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Jah Tubby preamp mods continued

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Category: Other Chat
Forum Name: Roots n Culture Forum
Forum Description: Talk about speaker box with other sounds here
URL: https://forum.speakerplans.com/forum_posts.asp?TID=21452
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Topic: Jah Tubby preamp mods continued
Posted By: Joseph Redhemption
Subject: Jah Tubby preamp mods continued
Date Posted: 19 November 2008 at 8:06pm
NEWNEWS FLASH Mostec 4 way on the bench
http://www.speakerplans.com/forum/forum_posts.asp?TID=21452&PN=10 - http://www.speakerplans.com/forum/forum_posts.asp?TID=21452&PN=10

NEWS FLASH  The resluts of the new crossover at this page http://www.speakerplans.com/forum/forum_posts.asp?TID=21452&PID=219657#219657 - http://www.speakerplans.com/forum/forum_posts.asp?TID=21452&PID=219657#219657




After modding a 3 way JTS preamp by adding tubes and upgrading the parts (see link to original post) http://www.speakerplans.com/forum/forum_posts.asp?TID=19980 - http://www.speakerplans.com/forum/forum_posts.asp?TID=19980 I decided to investigate further this preamp. In fact it is not the preamp I modded but another one from another sound from Geneva. In the future I will try to get back the modded one and make the same tests to balance the results.
The results below are made on an unmodded preamp.

I did make some measurments like frequency response, phase, distortions and some more tests. The results are sometimes very surprising.

Tests where done using a PC with EMU 1820M soundcard and RTA program.


This is the phase shifting measured from the preamp bass and mids crossover outputs.
PINK is Bass and BLUE is Mids. The problem revealed by this plot is the phase shifting that occurs around the crossover frequency set at 212Hz.


This plot shows the same problems but wiht the mids and highs output at 4330Hz
PINK is mids and BLUE is Highs


This is the frequency response plot taken at the tape output with all tone, equalizer and crossover pot at 12 o'clock. The parametric mids and bass pots are fully clockwise. For those who understand this plot no comment.
But for the neophytes this is the worst frequency plot I ever seen. An ideal plot should be flat from 30hz to 20Khz.

N.B : The signals taken at the tape output from the preamp are just the sum of the three crossover output.



This plot same as above exeption for the bass parametric that is fully anticlockwise.


this plot shows the behavior with a complex signal. Its an 1Khz sinus with harmonics up to 20Khz. In PINK the output of the sound card and in BLUE is the tape output of the preamp.


Ok this is enough for today. I will post other results this week like transient response and distortion.






Replies:
Posted By: Matthias
Date Posted: 19 November 2008 at 8:40pm
so finally someone did it...

we measured exactly the same frequency response, i would never ever connect this to my speakers.... Bass Dead

the bredda measured chose to let them not be seen by the public as JTS is a very respected manufacturer and this tests are poison for his business.

So maybe you should remove the plots ?!

It is a bit strange, on the one side people have to know that this preamp is soo bad, otherside when people have good ears and a bit of knowledge of equing this preamp can also sound good.

In fact, it just sells by its "traditional" character, not for its perfomance

The funny thing is, it is not possible to get real subbass out of this... parametric bossts at 50hz lowest frequency, this saves a little bit your speakers but it is not what people want when they speak about 30hz scoop bins Wink

To be honest, this plot is sweeeeet against the one we made. same curve but even deeper hills and valleys ....18db.... unreal stuff, i could not believe it.

I would say lets end this thread and respect to you for not believing everything people say

let us remove these posts and for those who where fast enough they were lucky, got the chance LOL


Posted By: RENSAAB
Date Posted: 19 November 2008 at 11:24pm
Fairplay to you for sharing these plots with us JR but lets be honest, i doubt whether anyone who purchases a JTS preamp is expecting audiophle quality or is even bothered about a flat response/phase differences etc.
 
I would imagine Tubbys is smart enough to realise that not many sounds play "flat", so i guess why not "tailor in " a typical response! I personally prefer equipment that can give a flat response when needed but the average sound system operator is rarely looking for that (others may disagree).
 
Just my two pennies worth  


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"The secret of the Scoop, what a wonderful piece of Science" - Tony ASS.

"when the amplifier and voice coil are in complete synchronicity there is magic" - A Well Respected Amp Guru


Posted By: mykey
Date Posted: 20 November 2008 at 5:44am

If you remove this, preamps will always be bad, atleast this will give the designer a kick and get things straightened out

Do agree with a lot of what Rensaab has said though



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......just all them hanging there like giant bananas.



Posted By: DC
Date Posted: 20 November 2008 at 7:27am
Why should tubbs make it better. The pre is used by many sounds for years. I think making it better will affect the character of the pre. And still it isn't that bad... a steep dip around 220, so what...and some boost between 40 and 50 is what a sound need. Things can be adjusted with the EQ The 30Hz cut is quite convinient as it will prevent your amps from consuming power wich isn't really audible. Some cut in tops.... hmmm, most sound attendenders won't hear anything above these freqs anyways.
Regarding the phase difference, i can't see the value for the timeline so these plots don't tell you anything.
Even the most expensive preamp will have phase shifting.
BTW would be interesting to see the measurements from the modded pre with tubes. I bet the phase shifting is even more and defo no flat responce either.
And also measuring thru an emu card like that won't give you fair measurements either.
If you got a good quality oscilloscope and good quality frequency generator then you can do such things.


Posted By: Matthias
Date Posted: 20 November 2008 at 11:30am
yes fellas, maybe the people just want something like this, but this is confusing me, i dont know... there could be also a flat response and you could eq it to this curve if you want lol.

Even in a 4 way, the "crossovers" are set so badly, no 12" plays up to 4k smooth.

I still think it is selling because of its traditional character, the preamps are very expensive for this performance. For this price, a flat response should be standard.

Things like this and the sound coming from it just keep down the roots music and many people of other music do not respect the works, because most systems i heard with this pre sound weak.

DC, i dont know if any Bass speaker could manage a boost of 12db +, at 50hz ( mine would not ) , the HP filter should work in this design, i think it is written in the manual that the lowest eq should always be turned down. ( 31.5hz probably )

Flat Bass response is not possible only a one  not bassline

We measured the same, even worse frequency response and also measured our soundcard, all i know it was ultraflat. I can ask what soundcard was used.

You as a very good producer know about the needs in the low mids, this section is quite the hardest to manage speakerwise and very important for every tune... if your speakers can do it and your preamp not... i cant follow.

The steep rolloff at 10k is not that dramatically, as you said most soundmen ears do not hear it, you could only get better highs with 100 piezos ;) This preamp is not really suited for a good 1,5" f.ex.

I respect jahtubbys as sound to the max, they had a really great influence over the years, that is why i said this is poison and i dont want to be a bad influence for his business, but the truth is also important.

I see that it would loose his character, i still think that everyone can build preamps which sounds good then...



Posted By: king david
Date Posted: 20 November 2008 at 12:01pm
if u have a preamp and combine scoops, folded horns, midrange horns, tweeters there is no chance for time aligment...
 
i have a jts 3way preamp and its a good unit, it has its limits, and this thread just confirm this...but it works good with a reggae sound cause it has a lot of useful things to colour the sounds and spice it.
 
everytime i play with preamp, sound isnt perfect (sometimes is very good sometimes is just good) but its great for live dubbing. with other equipment i can come close but i feel more at ease with preamp
and u dont see people at gigs doing measurements, they come to dance+have fun!
 
everytime i use the sound as a p.a....i bring out my crossover, equalizer and limiter and the sound is much much better!
 
cheers


Posted By: DC
Date Posted: 20 November 2008 at 12:05pm
Thing with these plots is the measured values depend on more parameters. Also gain setting is of importance, input level, what kind of input signal is being used. What is the source, etc, etc. Besides that... there's no scales on the pre sow how would you know what is the flat setting on the pre ? There's no accurate metering on the pre either.
I definatly heard some very good sound coming from the unit, but all depending on the operator. These pre's are built for soundmen who use their ears and not rely on metering.
As far as i know the so called 'Parametric EQ' is set at a fixed boost level and only shifts the freq up or down. So flat responce even not possible unless you turn down the lowend EQ.
But as said in the above plots all the EQ settings were at 12.00. So that explains the peak in the lowend.


Posted By: King Simeon
Date Posted: 20 November 2008 at 12:44pm
"The Truth is also important" 

The fact this is a 'roots & culture' forum means that the truth is in the history of sound system. These charts and the info seems better suited to the other parts of speakerplans. 

Tubbys pre's don't come with a booklet, they are sold according to what they do, and have been for many years. They are also sold at a reasonable rate and come with the back up that Keith can still service equipment bought 30yrs ago. Nuff new builders come and go, who is the one still around and running a successful business?

Tubbys also builds equipment for other businesses, that require the high end specifications you mention, when he builds a pre amp he builds according to his experience of playing sound.  I'm not sure i know of anyone who has more experience and 'in the arena' knowledge. 

Of course they could be better, tighter suited to the delivery of the speakers, but dont forget, every piece of equipment sold is also the same as Tubbys himself uses when he plays. They are regularly being updated. He doesn't blow his own equipment many times and in all the time Tubbys has been back in sound runnins, since 2000, no one has made a big fuss about him having the title, 'World Sound', nuff said.

I think that modern peeps are applying info to older technology. Of all the producers i know, just about all of them have 'older' equipment, use older produced FX, reverb, flanger, delays, eq's compressors... desks..... Some desks have 'character' a warmth... well if you run tests on them you would find that it would be 'distortion', now check out the prices on this equipment and how many people are after them! Are you saying they are all stupid/should know better?  

Some of the most sought after equipment now are older units, prices have only gone up and up. I see new eq's with hundreds of frequency controls, but they are lifeless, it just feels like you are playing with air. They are sold by the stats they offer, this frequency to point this of that.... They are sold on science, but to the human ear music comes out differently. People in music know differently, which is why they use their ears. I want to hear something sweet, warm, harsh and loud, dirty and gritty. Character!!!

I look forward to hearing new pre's, all new sounds, that is the only proof i want to hear. Make people know through the works it performs.


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https://www.facebook.com/KingSimeonSound?ref=stream     
https://soundcloud.com/king-simeon


Posted By: Joseph Redhemption
Date Posted: 20 November 2008 at 6:31pm
Raspect to every one who took time to write these remarks.

The truth is the truth and that is no offence

Thanks it is very constructive.

Sorry for the bad plot. I dont know what happens because the original plots are good. I ad a link below each plot for those who are interested.

Now to part two of results

This plot shows a real surprise. I was testing transient response by injecting a 90hz square signal in the preamp and this is what I get at the mids out. I cant explain this but normaly there should be no signal at all because we are way below the xover point at 212hz.
PINK is input and BLUE is mids out.

http://www.4shared.com/file/72242073/8a99278/Mids_out_squar_in_90Hz.html - http://www.4shared.com/file/72242073/8a99278/Mids_out_squar_in_90Hz.html

this is at the mids out with a 1Khz square in.
PINK is input and BLUE is mids out
The transient behavior is good. For shure this is no square signal at all at the output but this is not what we want and the cause are the blocking caps.


http://www.4shared.com/file/72242063/11b2a339/Mids_out_squar_in_1Khz.html - http://www.4shared.com/file/72242063/11b2a339/Mids_out_squar_in_1Khz.html
http://www.4shared.com/file/72242063/11b2a339/Mids_out_squar_in_1Khz.html - http://www.4shared.com/file/72242063/11b2a339/Mids_out_squar_in_1Khz.html

This plot shows a burst. It is at high frequencies >10Khz.
It shows that in the high frequencies some details are lost but if you believe like some who wrote that most soundmen didnt hear this freqs then it should be no problem for them.
PINK is the burst and BLUE is the tape out of the pre.

http://www.4shared.com/file/72242032/1bc267ea/Burst_tape_out.html - http://www.4shared.com/file/72242032/1bc267ea/Burst_tape_out.html

This is the THD (total harmonic distortion) with a 1Khz sine input. Not too bad, very acceptable. 
N.B. the signal led is not blinking look below when it blinks.

http://www.4shared.com/file/72242082/f836be21/THD_led_off_1khz.html - http://www.4shared.com/file/72242082/f836be21/THD_led_off_1khz.html




Same signal as above but the gain of the mids xover is raised until the corresponding led light up. Now distortion looks more like a guitar amp.
My advice is not to push the gain too much because when the led goes on the distortion become audible. This is because of the way this preamp drive the led. The signal is directly taken from the individual xover outs to drive a transistor who in turn drive the led.
It would have been better to buffer with an opamp before driving the transistor.
N.B. This can be a wanted effect to beef up the sounds.

http://www.4shared.com/file/72242105/af49cbbd/THD_Led_on_1Khz.html - http://www.4shared.com/file/72242105/af49cbbd/THD_Led_on_1Khz.html


Finally I want to say that I made these test to know whats happen in this preamp so I can improve them.
I'm working know on an linear phase xover to put into the JTS. For shure it will loose the actual caracter of the pre but hoping that it will sound more accurate/sharp.
I will then test this modded pre and compare the results.
Will it be better or worser? Wait and see
If everything goes well with the construction the results will be published next weekend.



Raspect





Posted By: mange
Date Posted: 20 November 2008 at 7:06pm
Originally posted by Joseph Redhemption Joseph Redhemption wrote:



This plot shows a real surprise. I was testing transient response by injecting a 90hz square signal in the preamp and this is what I get at the mids out. I cant explain this but normaly there should be no signal at all because we are way below the xover point at 212hz.



But a square wave is full of harmonics, getting no signal would be expected if you were injecting a sine wave. Surely a 90 hz square wave have harmonics above 212 hz.


Posted By: Joseph Redhemption
Date Posted: 20 November 2008 at 7:20pm
Alright this explain that
Thanks


Posted By: mange
Date Posted: 20 November 2008 at 9:01pm
Played around a little in Matlab (or actually GNU Octave).
I was using that a square wave can be written as an infinite series like this.

In other words, a square wave can be constructed by summing sine waves of odd multiples of the fundamental freq. from the first one to the inf. one.

In your example with the fundamental freq being 90 you would sum sine waves with the freq.:
90 hz, 3*90 hz, 5*90 hz, 7*90 hz ......, inf*90 hz

what i did was that I substracted sine waves with freq. lower than 240 Hz and higher than 4000 Hz from a perfect square wave. (xover points?)
I ended up with a plot looking like this: [edit - this is one period]


Edit: [pasted wrong plot first]
Comparing this to your plot you can see some resemblance..


But as I said, square waves are rather complex and it would have made much more sense to use a sine wave for this.


Posted By: mskeete
Date Posted: 20 November 2008 at 9:30pm
Originally posted by Joseph Redhemption Joseph Redhemption wrote:

My advice is not to push the gain too much because when the led goes on the distortion become audible. This is because of the way this preamp drive the led. The signal is directly taken from the individual xover outs to drive a transistor who in turn drive the led.
It would have been better to buffer with an opamp before driving the transistor.
N.B. This can be a wanted effect to beef up the sounds.
http://www.4shared.com/file/72242105/af49cbbd/THD_Led_on_1Khz.html - http://www.4shared.com/file/72242105/af49cbbd/THD_Led_on_1Khz.html
 
It's something I call the LED test. The circuit is OK as it is. The problem is due to something else


Posted By: DC
Date Posted: 21 November 2008 at 10:33am
I didn't say soundmen don't hear above 10k, i said most attenders. People who go stand in the middle of the arena and get harsch tops feeded into the ears definatly loose their high frequency hearing over time.


Posted By: Joseph Redhemption
Date Posted: 21 November 2008 at 11:20am
Originally posted by DC DC wrote:

I didn't say soundmen don't hear above 10k, i said most attenders. People who go stand in the middle of the arena and get harsch tops feeded into the ears definatly loose their high frequency hearing over time.
 
 
This is where the tubes come in and was the major upgrade to the JTS. The highs goes very high and they are so sweet. But for shure it depends of the driver you use.


Posted By: mykey
Date Posted: 21 November 2008 at 11:39am
Originally posted by king david king david wrote:

if u have a preamp and combine scoops, folded horns, midrange horns, tweeters there is no chance for time aligment...
 
i have a jts 3way preamp and its a good unit, it has its limits, and this thread just confirm this...but it works good with a reggae sound cause it has a lot of useful things to colour the sounds and spice it.
 
everytime i play with preamp, sound isnt perfect (sometimes is very good sometimes is just good) but its great for live dubbing. with other equipment i can come close but i feel more at ease with preamp
and u dont see people at gigs doing measurements, they come to dance+have fun!
 
everytime i use the sound as a p.a....i bring out my crossover, equalizer and limiter and the sound is much much better!
 
cheers
ShockedI do it in my head, the same as everyone else.
 
I'm sure if you went round with a questionnaire and asked people to fill it in on the way out, it would be all bad about the sound 
 
I have never been to a dance and been satisfied with the whole sound spectrum, there is always something missing or too much of something else
I have actually heard gaps in the crossover bands
 
most of it is down to the pre'sShocked
 
A selecta should own up and say he 'does not know' how a system work's, this way they could have someone with them who doesWink
 
what sound uses Digital LMS and a pre? would be interesting to find out
 
I know some will say i need to come back and listen, but it looks like I don't need to, seeing as this as cropped up
 
never heard one of yours though mskeeteWink
 
 


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......just all them hanging there like giant bananas.



Posted By: king david
Date Posted: 21 November 2008 at 12:23pm
when i play out and bring the sound i always bring the preamp, it has lots of useful things for live dubbing, i connect to the fx units and since i play lots of instrumental dubs, it works great for wild remixing...people would be much more into listening this wild things+looking at a selecta "working"on the tunes than taking care of missing frequencies
and when i see sounds playing out and they have their custom built equipment, stuff u cant buy in the shops,thats great, and it makes every sound different and not the usual dj thing with 2 decks and pioneer dj mixer and stop...
i know the limits of jts preamp, and u can add eq, other boxes(i tried to add a crossover+15"reflex or folded horns to ahve more lower mids) but theres no chance...use it for what it does dont ask for hi fi sound, if u want that go through normal dj-p.a. equipment.
also the 3 way is 30years old design...i found out it sounds better with roots music than with digital dubs
i have some boxes in my living room now and i'm listening roots and its perfect, it sounds "very reggae and warm" Tongue
 
i dont know about mostec, i just saw king shiloh with a 4way mostec, and the sound was excellent. so big respect to mostec, when i win the lottery i will try different preamps, no money to spend on it now. but really if theres a preamp that can work with different music styles and can give a flat response, while keeping some character of a classic preamp(kill switches, fx, parametric....) it would be perfect!
 
 
i did p.a. for a dub band 2 months ago, they played on my soundsystem, from their mixing desk to my preamp...sounded ruff and powerful but really lo-fi
we did it again 1 week later and used crossover, eq and limiter and no preamp. it sounded excellent!
i would never use the preamp again for a band or p.a. service.but when u come to dance to the warrior charge soundsystem, the preamp is essential!
 
just some random thoughts...


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http://www.warriorcharge.noblogs.org


Posted By: King Simeon
Date Posted: 21 November 2008 at 12:48pm
I'm glad we're getting a bit more open with the comments. I'll admit to being a traditionalist and even stuck in my ways, but i would not wish to hear roots and dubs played through a clinical/quality sound system... seems pointless/soulless. Most of the old tunes are not high quality made/mastered so what is everyone going on about?? I would love to hear different sounds with different equipment bringing each different character of sound, and hopefully different tunes!!

When it come to other music... well i wouldn't want to hear any of them through a pre. Makes no sense, just as half of the talk makes no sense. I was at SE1 last month and there was some big pa in one area and Tubbys/Aba/Ch.1 in the other. The pa sounded LOUD, but no dimention, the tops squeezed into the sound and the bass was boomy, but no round definition, just overall loud, compressed/crisp. But thats for there music, (Garage/R&B/Urban), they have it how they want it.
 
When Tubbys warmed in it was impressive, got a good few 'woofs' people couldn't help smiling and looking at each other, people banging on tables, like the old days. Nothing fancy, just simple control on sounds. No harshness, just power/sound. Everyone sounded different and all the better for it. Some folks don't run that clear, it is true, some could work a bit harder on there skills... but that is how it runs. All this clinical talk is entirley missing the point.. this is a roots and culture forum. . . . did i miss something?


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https://www.facebook.com/KingSimeonSound?ref=stream     
https://soundcloud.com/king-simeon


Posted By: DC
Date Posted: 21 November 2008 at 1:05pm
When Russ is @ the controls... he make sure it sound good. As said it upto the operator.
I've heard Russ get a real crisp and clean sound from a JTS pre. Steve Vibronics also know how to operate the JTS. But it definatly also got to do with the gear after the pre.
See some people getting an extra xover after a 3way pre trying to make a 4 way sound.
As King David says... use gear what it's built for. Soundsystems are not aiming for the highest soundquality but for a vibe (and some just for bass)
 
Shiloh using speakermanagement systems these days and that improved the sound significantly. It not only upto the preamp.
 
And esides all that... the one tune sound different from the other. Like lots of digital dubs are being mixed straigt in the box and that don't contribute to the warmness of a tune.
As Simeon mentioned.... some producers seek for older gear just for the charater of the sound. For instance i used to have a mackie console and all my mixes were done on that desk but i felt the desk lacked some warmth. Just couldn't achieve what i wanted. Now since june i own an old Soundtracs console..... and made the difference.
So soon come 1st release mixed on that console


Posted By: mskeete
Date Posted: 21 November 2008 at 3:51pm
DC, I think yuou need to give me some pre release mixes of the tunes dem so I can check they sound compatible with my preampsSmile
 
Shiloh were also using a LMS when they had a JTS preamp
I actually think the LMS can cause some headroom issues but that's for another topic
 
got some more comments to add but got to dash


Posted By: DC
Date Posted: 21 November 2008 at 4:10pm
Originally posted by mskeete mskeete wrote:

DC, I think yuou need to give me some pre release mixes of the tunes dem so I can check they sound compatible with my preampsSmile
 
Shiloh were also using a LMS when they had a JTS preamp
I actually think the LMS can cause some headroom issues but that's for another topic
 
got some more comments to add but got to dash
Haha... well them being tested thru your pre a lot and i can tell you ... them compatible.
My only advice for your pre is to use a bit more sturdy kill switches.


Posted By: Joseph Redhemption
Date Posted: 21 November 2008 at 7:04pm
Are those who satisfy themselfes with a not too bad JTS pre  forgetting the human nature?

Aren't we always wanting better for ourself,family,friends,humanity?

Aren't we folowing the example and teaching of his majesty? Be a better man thru
 education ?
I'm trying to explain - with the help of others -  to everyone what happens in their pre and even show them a way to make it sound better and some of you complain about that!

As Ijahman say - JAH IS NO SECRET.

And same thing apply to sound. There are no secrets. It must be told freely to everyone how to use and make sound with quality to spread the culture.
And as soundmen it is our roots and culture to know how our soundsystems works and the ways to improve it. We always have to give our best when spreading jah words.

I was hoping that people will post ideas to improve further this pre but I'm very disapointed . Anyway InI still continue pushing this pre to the max.


Posted By: Deadbeat
Date Posted: 21 November 2008 at 7:31pm
If you want to try to see how the transient response is, would running an impulse response help as opposed to your square wave?


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Away on extended leave.


Posted By: russ d
Date Posted: 21 November 2008 at 10:10pm

the thing is the way your putting it is like the jts pre-amp sounds absolute crap, yet many of us that have used them, and many of the people that come to dances, hear it sounding perfectly fine, and they have satisfied sound systems and dances over the last 3 decades... also, your only talking about a jts pre-amp, you have not evaluated any others to put it into context, for all you know mostec, links, lincoln, destructor, barracuda, metro etc all might come with the same spec and plot `inadequacies`, and if so then it means that the jts sits amongst its peers quite satisfactory, and you can bet your life none of them are made with any better components... so if then all of these pre-amps would sound bad, by your opinion, then surely the sound system world would`ve flopped many years ago... i can agree that there is no problem in trying to forward things, but your words need to be put into context... if no pre-amp out there is of any worth then can YOU supply the world with what you would consider decent pre-amps, are you going to go into manufacture and turn things around, will you be able to modify every existing pre-amp to come up to your level of acceptance ?... i think not, and as such people should know and understand, that the pre-amps out there, jts included, can do the job they`re made for when used right... if any `sound man` out there cant get a decent sound going with this gear then i`d say they really need to take more time to learn their art !

btw, jts dont want his pre-amp runnin flat response, who runs a flat response sound system ?...that would sound dull and flimsy and weak as dishwater, we want BASS, we want the system slashing the tops of our heads off, thats the vibe, not some safe pa sound bizness, thats for disco`s and bands, when you ever go see a band and it drops like a sound system...never... and thats why we love sound system... gimme the vibes of shaka`s ol` sound, distorting and rumblin` away, shaking down the walls of jericho, no place for a weakheart... if you wanna bring jah into it, thats JAH vibes !

anyways, dont take offence, nothing is meant so, keep on doing what your doing, but just make sure its all in context.
 


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Disciples on I-Tunes.

Disciples on Bandcamp: http://russdisciples.bandcamp.com/

Facebook: russ disciple

Youtube Channel: http://www.youtube.com/user/sargantbrown?feature=mhum


Posted By: Joseph Redhemption
Date Posted: 22 November 2008 at 11:03am
Raspect Russ

Blessed be the one that shows you things you know already under a different aspect/angle.

I should perhaps be more political correct and say that the components aren't the best suited for their intended applications and jah bless sound come out of the box.
But I'm not of this kind.
You say that since 3 decades these preamps are fine. Maybe in UK.
Here in Switzerland all of those I know who have a JTS pre are NOT SATISFIED. All those I know having a mostek don't complain at all. Perhaps mostek are easier to use or are of better quality. I never got one in hand so I cant say.

About the frequency response measured at the tape out there is a real problem. The bass out is only capable of max one octave  at a time instead of a theoric two and a half octave. This is due to the parametric bass who is set too sharp and this results (not always) in a one note bass line. For shure I want a boost in the bass but I don't one of this kind.

So now to the good points of the JTS :

It is complete - Phono, line, mics, fx send return, eq, parametric mids and crossover.
The parametric mids is really good and usefull to spice it up.
Its a simple design easy to repair.
Acording to the tree point above the price is correct.

Bad points of the JTS :
The sound is not great ( very personal )
Its only one chanel ( you have to choose if you want to listen to the right or left channel of your records )
The tendencie to hear a one note bassline.

And about you're question if I gonna supply the world with quality pre? Perhaps in a near future and until then I will modify/upgrade every pre that people give me. I have already 6 on the waiting list.

One love




Posted By: russ d
Date Posted: 22 November 2008 at 12:21pm

without disrespect to any of the swiss sounds, how long has switzerland been in the sound system business ?...  sound has been in the uk since the 60`s, it has a long tradition, if we here are satisfied with it then who`s to say what... yeah things can always be bettered, even with the jts pre the design and component use has`nt remained static in all the years, but its remained at a level that works for its intended use... if the swiss sounds want perfection then ok go look for something else, its thier choice, i will still stand and say that the jts pre can do a perfectly good job....

when i had my sound system i used an old early 80`s barracuda pre, i can tell you IT had its own sound, i`ve played a later 90`s barracuda and its different but still does its intended job, when i go play some club pa i usually take my little mini mostec, it does its job, i`ve used his bigger pre-amps only a couple of times, they also do thier job, i have used a lincoln pre-amp, its over complex but when understood it too can do a job, and i have used on many, many occasions both 3 way and 4 way jts pre-amps, and never had a problem with them either, they all have different characteristics, and of course all have to be learnt and understood...(i`ve had many studio mixers over the years and its exactly the same with them too)... on each and every occasion i treat each pre-amp the same, use as little eq as is neccesary, and balance using the bass/mid/tops controls, in the end i use my ears to get the sound i want, i will not say its THE perfect sound, but its the sound that will suit me, most times it also works for the dance...
 
your point about the jts pre-amp being mono, all the makes are, and its VERY easy to use a stereo to mono adaptor for any stereo attached gear, no one side missing !..if people cant figure that one out then its back to school !...but, the newer 4 way jts pre does come with `stereo` phono`s for decks and cd (albeit internally linked, which does the exact same job as the mentioned adaptor), so no more confusion !
 
well, good luck with all the conversions, i`ve probably sold about 20 - 30 jts pre`s over the years, and i know tubby has probably sold 10x + in that time, jah knows what before, so maybe that`ll keep you busy... in the meantime jts will keep supplying as is, so no worries for your future work !


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Posted By: Jhodas
Date Posted: 22 November 2008 at 2:22pm
@ Joseph.

I appreciate what you're trying to do. I've hear some members on this forum describe what goes on in a preamp as 'witchcraft', so furthering understanding of what to some is an  unknown quantity can only be a good thing.

I am curious to know how the Tubbs preamp sits in comparison to others. (Mskeete?)

At the end of the day though, taking a plot of a preamp is like simulating a scoop. It's only going to tell you half the story (if that!). But then Soundsystems have always been something of a paradox.

Scoops shouldnt work, but only one top sound doesnt use them.

Piezo boxes are a techicians nightmare, but again, only a very few sounds don't use them.

The preamp is just another link in the chain of things that really shouldn't work, but just do.




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Until the Lions have their own historians, tales of hunting will always glorify the hunter.


Posted By: Masai
Date Posted: 22 November 2008 at 3:28pm
Bloodfire!

Seems like there is a bit of Tubbys bashing going on here!

Will reply when I've got more time........


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Facebook: Masai Judah


Posted By: King Simeon
Date Posted: 22 November 2008 at 4:50pm

Joseph, i'm not dissing what you are doing, i think it is great that people have ambition to do such things, but like Russ has said, it is the way you are making your points. As this topic has gone on, there have been some very slack comments made that have been pretty slaunderous. A lot of diss-respect. 

I dont think any teachings place science to be this important, dont forget that science ammounts to a religion of it's own, coming on like a false prophet and idol bizness! The way the human ear works and how it is works with the brain is more siginificant to the way we appreciate hearing music than any piece of equipment, so lets not go too far with what is right or wrong at the mechanical stage. We are dealing with music of expression, that it was the music is about.

If you met tubbs and talked you would know that he knew much of the same as you, but with a whole lot more applied knowledge through the times. He tests equipment for big manufacturers, tests specs on loads of equipment, just the same as you, for the interest/love of the subject.
 
The bottom line is; there is not a definite science to sound, i know you are taking it like there is, but the brain does not come with a same plan as your charts. 
 
I think everyone is excited to hear your new pre's, i look forward to hearing one in the UK, alongside others.
 
On another note........

Masai... was that your pre Aba was warming up with yesterday...?   



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Posted By: Joseph Redhemption
Date Posted: 22 November 2008 at 6:01pm
King Simeon
Please show me what is diss-respect full in my posts. I just read them again and found no dissrespect in any way. I said that he sell preamps overpriced, some components inside are not made for audio and I dont like the sound.
Sorry if you felt slack comments, to my excuse english is not my mother tongue so perhaps my ideas and opinions go straight to the point.
And for shure there is no exact science for good sound but there are rules that you cannot deny like ceramic capacitors are not made for audio signals or electrolytic caps used as blocking caps with audio signals,...
Finaly I totaly agree that we are dealing with music of expressionTongueCryConfusedThumbs UpThumbs Down but here its a talk about the technical side of reproducing music and the price we are ready to pay for a certain quality of reproduction and nothing more.
Thanks for your posts, one more time you showed me what I already knew with a different angle. Rastafari


Russ
If you connect thru an adaptor the two channel of the TT to an phono input you will loose bass and it will sound edgy. This is because you parralel the cartridge coils impedance thus dividing it by two and so the load impedance will be to high. Same apply to load capacitance.
This is not a rule for every cartridge (coils impedance vary from 500ohms to 5kohms) so try before ( but it will have an incidence with every cartridge and in the worst case you will have a heavy boost of 5-10db around 13Khz to 20Khz).


Posted By: King Simeon
Date Posted: 22 November 2008 at 7:12pm

It's cool. You have been very specific with your topic, i totally respect what you have written. I am also greatful you speak English so well, so that we can engage in the subject. We English are the nation who struggle with language abroad!!LOL

I did not say you had been dissrispectful, i mentioned that during this topic some people had. I don't mention names. From the early days of sound things have changed, people trying new things, even people doing old things, but calling it new!! It is all part of the music/culture. No one is trying to stop any development... the more the better, new music, new presentation, new was of playing and expressing it is vital.

I just dont like topics when they don't stay positive to the point of the subject. A couple of us made points to make sure this section is the Roots & Culture section, not just part of the technical Speakerplans site. The two should work together.
 
Rspx for the news. Keep us all updated... you've created a good interest now!!

 



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https://soundcloud.com/king-simeon


Posted By: Matthias
Date Posted: 22 November 2008 at 7:54pm
i want to say that i dont like too clinical soundsystems too, i love it to hear different sounds from different systems.

I also do measurements with my ears, and when i hear no lowmids then something is missing for me ( personally ) also from my own experience in playing out it is a very important freq. range

I am sure that there are people around which can make it sound good ( not as good as it would be a flat response ), but i dont understand why not build a flat preamp ? It is exactly the same unit, with lots of fun playing on it, and you can also eq it like this response... BUT you could have a nice round bassline ( why so sharp "parametrics" )where you hear every note AND you feel it in the chest too...   i know a builder which builds flat pres with audio suited components and this is a 100% improvement . You can also eq what you want and get your own sound ....

For me personally, a Roots soundsystem should be always a progress and has forward vibes to me, i cant see why it is bad to improve things and bring them to a better level. As mykey said, it is not only the preamp, it is in fact the speakers and they want the food what they are made for. If you like to eq the lowmids out, then do it, it would be all possible, if you want to boost 5k 12db then do it ( i bet many would not do it :)

It would not affect the vibes i believe ! I also respect the traditional character and the people which go for jts, but i am missing the progress a little bit and many people just go for equipment which has a big name. No offense from my side to jts and i totally respect his works, even i still find the pre is overpriced for this performance. I am always up to pay people for their works and like small shops and people which go another way then the rest of the audio industry, but this is too much.

Respect

Respect


Posted By: Masai
Date Posted: 23 November 2008 at 11:46am
All me can say is WOW!!!

As that ragga tune went 'me can't believe me eye!!!'

There seems to be a case of the blind leading the blind, here.......

NO DISRESPECT INTENDED TO ONES AND ONES!!!!

I'm writting a loooooong post to all of the above.

As a good idren of mine use to say, when he was on radio..........

'Soon come a road'Wink

Simeon - No bless - it's not my pre. Maybe it's a new JTS unit.......
Don't worry, I've got some designs on the drawing board. You know what I'm gonna say...... 'soon come a road'Wink

By the way, I used to post under the name of Othello. I wanted to do all my Geordie Le Forge/ Panthro posts under that name, and all the non tech stuff under Masai.

Can't get back to that account, and can't be bothered to be honest.

Oh yeah, this is the 'Roots and Culture Forum' on a technical website! Where else are we to discuss the science and art, of sound system culture? Think about it.....
Blood and Fire for non tech discussions, Speakerplans for all the techie stuff. Obviously this is not the law, as both have crossed over - which is good.

Got runnings to do, but keep the posts coming. I post up my novel soonWinkLOLEmbarrassedSmile

Give Thanks

Masai


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Facebook: Masai Judah


Posted By: mskeete
Date Posted: 24 November 2008 at 2:13am
Originally posted by Masai Masai wrote:


By the way, I used to post under the name of Othello.
 
had a feeling it was you but wasn't 100% sure
Looking forward to your comments (I hope)


Posted By: mykey
Date Posted: 24 November 2008 at 3:11am
the chicken or the egg?
 
when I was A yut dem, sound systems were very bad, cabinets were made from chipboard and the rattling was super annoying, you could NOT enjoy the tunes
 
Now you can't tell me that all the people at those dances liked that, they would have wanted EFFORTLESS warm bass coming at them, with HIFI tops
 
Now! at a very young age (14) I started out to try and help with this problem of cabs rattling, I started to build cabs that were strong. IMPROVEMENT
 
also lets look at piezo's, were they there because they were nice and cheap, or was it the sound of them?
 
then all of a sudden, people started using JBL & celestion bullets. IMPROVEMENT 
 
I saw back in the day , everyone upgrade to ASS kit. IMPROVEMENT
 
now, if you read through what has been said, you are saying that it's an authentic sound you want to keep?
 
so why don't we go back to the begining?  amplifiers in biscuit tins, chipboard scoops, and piezos?
 
why go and spend BMW money on a sound system then put a pre on it? 
 
if you want this, i vcan build some scoop with the rear baffle machined out to 21mm and use a 18mm rear baffle board with no glue, this will sound very authentic, but NO IMPROVEMENT
 
can I have a FLAT response PRE please to put on a BMW costing sound system please?
 
Another thing, all my matesDads back in the day had PROPER amplifiers and beautiful HIFI and pre-amps on some lovely Tannoys, so they could listen to their lovely reggae
 
not a piezo in sight, only lots of lace doilies on sofas


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......just all them hanging there like giant bananas.



Posted By: mskeete
Date Posted: 24 November 2008 at 8:18am
mykey, not every preamp is the same
On paper, my preamps can play flat (except one model). One day I actually bothered to measure one. Been looking for the graph all week but can't find it
 
There was a slight hump because I had the bass finishing at 160Hz and the mids starting at 130Hz. It was my own one that I use to experiment on so I left it as it was
 
Now, I'm not suggesting for a second that I would play a session with a completely flat response (I wouldn't) but I have more of a choice and I can play a wide range of music (not just reggae) and be happy with the sound
 
Not bashing JTS or anyone else. Just saying that not all pre's are the same


Posted By: Masai
Date Posted: 24 November 2008 at 9:05am
Originally posted by mykey mykey wrote:

the chicken or the egg?
 
when I was A yut dem, sound systems were very bad, cabinets were made from chipboard and the rattling was super annoying, you could NOT enjoy the tunes
 
Now you can't tell me that all the people at those dances liked that, they would have wanted EFFORTLESS warm bass coming at them, with HIFI tops
 
Now! at a very young age (14) I started out to try and help with this problem of cabs rattling, I started to build cabs that were strong. IMPROVEMENT
 
also lets look at piezo's, were they there because they were nice and cheap, or was it the sound of them?
 
then all of a sudden, people started using JBL & celestion bullets. IMPROVEMENT 
 
I saw back in the day , everyone upgrade to ASS kit. IMPROVEMENT
 
now, if you read through what has been said, you are saying that it's an authentic sound you want to keep?
 
so why don't we go back to the begining?  amplifiers in biscuit tins, chipboard scoops, and piezos?
 
why go and spend BMW money on a sound system then put a pre on it? 
 
if you want this, i vcan build some scoop with the rear baffle machined out to 21mm and use a 18mm rear baffle board with no glue, this will sound very authentic, but NO IMPROVEMENT
 
can I have a FLAT response PRE please to put on a BMW costing sound system please?
 
Another thing, all my matesDads back in the day had PROPER amplifiers and beautiful HIFI and pre-amps on some lovely Tannoys, so they could listen to their lovely reggae
 
not a piezo in sight, only lots of lace doilies on sofas



You done know, king!!!ClapClapClapClapLOL


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Facebook: Masai Judah


Posted By: Masai
Date Posted: 24 November 2008 at 9:08am
Originally posted by mskeete mskeete wrote:

Originally posted by Masai Masai wrote:


By the way, I used to post under the name of Othello.
 
had a feeling it was you but wasn't 100% sure
Looking forward to your comments (I hope)


Yes, me ol' mucker!!! As theyuse to say in Highlander 'There can be only one'Wink

Must link up, soon.

Got to run. As the yoots would say - I'm on the grind. No laughing at the back, please!!!LOL

Give Thanks


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Posted By: Dub Defector
Date Posted: 24 November 2008 at 9:50am
All seems a bit odd to me, just saying that because something has been done the way it has for x-number of years does not mean it can't be improved. Even in reggae sound system business things have progressed over the years.. every part of the system has been upgraded from speakerbox to drivers to amps. Dubplates a run from Acitate to DAT to CD over the years.. (remember nuff heated debate about that one!) but things move on. So what gwaan with Preamp? We have to stick with Tubbys coz its been run fine for 30 years? Things move on.. and for the better IMO.

I'm not bashing Keith, we run one of his preamps (just had it serviced Wink) and things never sounded so good on our system... no complaints from me on that front. But say it cant be improved? and that the pre is 'the' character of a sound system? Why don't we go back to quad speakers built from wardrobes with 150 watt drivers? Now that is authentic!


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Rough Every Time... http://www.dubselector.co.uk - http://www.dubselector.co.uk


Posted By: mykey
Date Posted: 25 November 2008 at 4:44am
A mechanic or a carpenter will always have is favourite tool
 
that tool will be the best in the tool box
 
the Pre is a sound mans favourite tool.........but is it the best?
 
lets make it a proper tool!!
 
then I'll buy oneShocked 


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......just all them hanging there like giant bananas.



Posted By: mykey
Date Posted: 25 November 2008 at 4:45am
yes, done now MasaiEmbarrassed

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......just all them hanging there like giant bananas.



Posted By: mskeete
Date Posted: 25 November 2008 at 7:34am
Originally posted by mykey mykey wrote:

A mechanic or a carpenter will always have is favourite tool
 
that tool will be the best in the tool box
 
the Pre is a sound mans favourite tool.........but is it the best?
 
lets make it a proper tool!!
 
then I'll buy oneShocked 
 
and what's your spec of a 'proper' pre


Posted By: mykey
Date Posted: 25 November 2008 at 10:14am
Thats something you should be asking everyone
 
if you haven't already got your foot on ladder, maybe here's your chance
 
East London styleeWink
 
be quick before the Swiss get in there, we don't want them building Pre's as good as their time pieces 
 


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......just all them hanging there like giant bananas.



Posted By: Masai
Date Posted: 25 November 2008 at 9:34pm
I've just realised........

Nuff amp builders come from the endz (East London)!

Baracuda, Tubbys, Elvins, Mostech........

Anybody else?

You're right about the Swiss! Don't forget the Swedes, too! I know dem can build some good speaker boxes!

It does amazes me, how the features of the pre haven't changed in nearly 30 years. From when Bara came on the scene with his pre, JTS refined it, and there hasn't been much change since.

Same input channel featues, 10 band graphic eq (why?), parametric eq (yeah, right!), and how can I forget, the must have feature of all pre's - kill/ cut-out switches! With matching red, yellow, green, matching LED's and knobs. Yes, iya!LOL

Can anyone tell me when you last hear someone use their pre, to create a sonic delight?

The creativity it seems, has diminished. I think a lot of the music that the sounds play, also reflect this. Too be honest, if you have a pre with a flat response, and you're playing mainly UK style roots, it's gonna sound pretty lifeless. You see my brederns and sistrens, we are caught it viscous cycle. Sound system produces a certain sound, producers then try to replicate this sound on their productions, sounds play the tune, next producer trys to replicate this sound, etc.... Pure sub bass, stinging tops, not much in the middle. I'm sure if you looked at the graphic settings of most man's set ups, you will see the smiley face configuration. You put the mids up so that you can here the vocals, melody, chords, man start fi bawl!!!LOLConfusedCry

That's not to say that there are some good tunes being produced, but maybe it's a case that they are not being played because they are too 'musical'Confused or 'not hard enough'ConfusedConfused

I just wanna hear good tune, pon a good set. I wanna hear n feel the bass, but I want to hear the WORDS, the instruments, EVERYTING!!! I don't expect it to sound like a hi-fi, but if it did, is that such a bad ting? I don't my ears bleeding.

Audio electronics has been my profession for over 20 years. As soon as I mention Reggae, they (work colleagues) start to try and take the pee. It's only when the try n test me, they know that I'm not 'a typical Reggae man'. I remember one time when a ex colleague started to talk about about drum machines - Roland ones. When I started to correct him (which came first - 808 or 909, what was the difference between the two, etc.), he turned around to me and said 'You know your stuff - don't you? I don't want you to be offended by what I'm going to say (I thought 'here we go!'), but I've never come across a Black man like you' He started to comment about my knowledge, skills and workmanship, and how their isn't that many (Black men) in my field. In fact, we counted them, on one hand! I'm only talking about bredrens in technical positions (engineeers who can diagnois and repair to component level), in the music technology field and pro recording/ studio field. Not to say this hasn't changed, in the last few years.....

When they had a leading Reggae studio call up (they were a client), they use to roll up! You know what? I couldn't defend dem!!!

As a Nubian, I've had to deal with this ism n scism, as well as the other stuff. It's like someone who has studied to be a doctor, but also knows about alternative medicine that what used in his village by his elders....

Humble Tafari started a thread/ topic, several weeks back, where he stated that nuff of the UK sounds and sound men, are not doing enough in their communities (as well as some other stuff that he outlined). I agree with him. He made some good, and valid points

That's why I'm on a mission to educate the young people, with the knowledge and experience, that I have been Blessed to have gained, throughout the years. If one out of a hundred picks it up, it would be worthwhile. I'm going to do my best to help my Nubian young people. I won't and haven't excludeed others, but they are the ones, at the bottom of the pile right now. I'm working on a lot of guitar ampliiers lately, and there is a yoot who has shown some interest in electronics - the others don't give a toss! He will pop his head in my workshop and look over my shoulder and ask what's wrong with it, etc. I just tell/ show him, and sometimes show how bad some of this amps are badly put together (don't get me started on Mesa's!). He is of Anglo French descent.

Soooooo! Let's just keep tings on a positive heights! Yes, we should be critical of tings (bits of equipment in this case), and improve on tings, but let us not pick on something that has been a successful product for many years - just because you don't like it.
Better we just try to educate ones on how one feels sound systems should sound like, but remember that it's all subjective - he saysWink

If you was to look inside a Marshall amplifier, you would be shocked!

By the way, just look at the frenzy about the Bara on Ebay '£370'???Confused  'If I had the money I would pay a lot more for it'!!!ConfusedConfused

Now I wonder what ones would say, if they opened up that pre, to have a peek???Wink

Spectrum analyser at the ready, sah!!!

Me mother just ring to say she have some fish fi I n I, so me gawn!!!Tongue

By the way, this is not me novel. It was only meant to be a short reply! Just got carried away, while I was doing some other workEmbarrassed

Keep the positive vibes (and jokes) flowing, and keep the Fire burning!

Give Thanks and Praises!!!





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Facebook: Masai Judah


Posted By: Sheggy
Date Posted: 25 November 2008 at 10:24pm
Got me reminiscing Masai!

I was born and grew up in the East End (E2). I used to read Echoes, dream about having a roots sound, shop at Elvins, M&D, and even bought my first bits of gear from Elvins and Hi-Tec on Dalston Lane. I'd always go window shopping and then go Ridley Rd.

Most of all I wanted a Barracuda pre ('member the adverts in the back of Black Echoes?)!

I learned everything I know about music from black music, I learned most of what I know about sound from reggae sound system. I learned most of what I know of audio electronics from a black jamaican teacher and many of my heroes are self taught electronics technicians - I mean lets not forget King Tubby!

I fully support what Joseph is doing and I can't see his work as a criticism of Barracuda or JTS but nor can I argue with the sounds that I loved to rave to in the dances of the eighties and nineties (all Barracuda and JTS). 

But remember, when certain Jamaican producers wanted the edge on the competition they went outside: the Hoo Kims got API from Miami and the sound was fantastic. 

Now if I was a sound operator, I would comission an API pre based on a Barracuda system. 

Then I'd go Ridley for sumpin' fe nyam.

S



Posted By: Dub Defector
Date Posted: 25 November 2008 at 10:47pm
Truth truth about the music.. this happened in the 90's as well.. nuff sub standard digital uk roots dub coming out at that time. Things went bad and the roots market died a death in the late 90's IMO.

Originally posted by Masai Masai wrote:


By the way, just look at the frenzy about the Bara on Ebay '£370'???Confused  'If I had the money I would pay a lot more for it'!!!ConfusedConfused

Fe sure i would (maybe not 'a lot' more but still).. secondhand JTS pre is gonna be £300/350, so Bara is less common and comes with history Wink so worth at the very least what it went for IMO


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Rough Every Time... http://www.dubselector.co.uk - http://www.dubselector.co.uk


Posted By: Masai
Date Posted: 25 November 2008 at 11:58pm
Yes Sheggy!

A true born cockney!

So you must remember when Hytek was Park West, and Johnson & Jones, then?!

Yeah, I remember the ad. It look as long as the QE2! And yes - I wanted to get my hands on one, tooWink

Do you remember the ads by Cass Electronics? He use to say he was ex army, in his ads...

Good for you! Not sure if King Tubby was self taught, but I take your point. Can't forget man like Mad Professor, who was not self taught. He built his own mixing desk, and made a few hits with it tooWink I know he has upgrade that desk, to one of the most highest ranking brands in the land.....

I'm also self taught, but I also went to college (Hackney being the first. Keltan House on Well St.) and Uni (London Guildhall it was called, back in the day), and have no regrets.
Like I said, as a Nubian growing up in dem times, I couldn't get companies that i have worked for, by saying 'I know how to make a pre amp' but not having a clue of how it worked.
As my parents and elders said dem times (some of you would have had it said to you too) 'you will have to be at least twice as good as the white man, who is going for the same job'. Someitmes, it still wasn't enough.....

I found the myself on the otherside of the fence, when I had to interview a bredren who had come to apply for the post of an audio engineer. I was the head of the audio department at that time. We had contracts with hi-fi shops in Tottenham Court Rd, East End, and manufacturers (Sony, Phililps, B & O, Fisher, Sanyo, are a few I remember)

The first thing he said was that he can build pre amps. I said ok, but let me show you this - I pulled out a schematic of a typical amplifier. I asked him if the amplifier was dead - no power - where would start to look. After a long pause, he pointed to the output stage, the pre amp stage, and other places, but got it wrong all the time. I showed him the area, and gave him a few tips. He said him don't know about dem tings, but he can build pre! He pulled some schematics he had drawn and said 'you get a wicked b-line when you dis ting here, and if you change dat one der.... I said 'what is the component you want to change doing? How do you calculate it's value? He couldn't answer...

Did he get the job? Stay tuned for the next episode.....

I don't profess to know everyting about audio electronics, but I'm glad and Give Thanks for the knowledge inna my head, thus far. I'm always ready to learn, and am doing so with valves/ tubesSmile I've got ideas with dem, babies! Soon come a road - The Father willing.....

Yes' I know that the Hoo Kims wanted the best at the time - API. I think Joe Gibbs had one as well...

I may be working on some API stuff. I will keep you postedWink

Don't get it twisted. I'm not saying that Joseph or anyone else, shouldn't go ahead and improve a pre or whatever, but most people improve on something, because they like the essence of that what they are improving. A man pimps up a car but he likes the shape, a man chages the caps in his Marshall amp but he still loves the original sound, you like a certain recipe but you add a take away an ingredient, a man improves a pre because he likes the sound already, but thinks he can get to 'sound' even 'better'....

Like I told Joseph before, I would rather he build a pre from scratch, as I think he would produce a good unit.

API and Bara?!?!?ConfusedConfusedLOLLOL

I'm not saying nuttin'!!!

Except that you should go an fill you belly down Ridley first, before you die of hunger bruv!!!LOLLOL

Give Thanks!


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Facebook: Masai Judah


Posted By: King Simeon
Date Posted: 26 November 2008 at 12:01am
It was a good read today, cheers for that guys!!Clap
 
On that Bara/£370...! I can imagine its gonna cost a whole lot more than that before it sounds sweet again in yr3000, and could well be a headache to find someone good enough to open it and prepeared to spend time! Despite the 'want' factor of some of these legendary older pieces, the reality of actually using them/having them is often quite different and leaves you a bit sore!!!LOL  I've heard enough soundman offer there experiences, very greatful to them too.
 
However, with the likes of Masai about the place... and the internet, these things might become easier to fix, and with more openess/sharing across Europe.... interesting.
 


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https://www.facebook.com/KingSimeonSound?ref=stream     
https://soundcloud.com/king-simeon


Posted By: Masai
Date Posted: 26 November 2008 at 12:05am
Originally posted by Dub Defector Dub Defector wrote:

Truth truth about the music.. this happened in the 90's as well.. nuff sub standard digital uk roots dub coming out at that time. Things went bad and the roots market died a death in the late 90's IMO.


I agree. It would be good to hear other peoples view on this....

Originally posted by Dub Defector Dub Defector wrote:


Fe sure i would (maybe not 'a lot' more but still).. secondhand JTS pre is gonna be £300/350, so Bara is less common and comes with history Wink so worth at the very least what it went for IMO


True. Let's see if the current economic climate will have any effect, on the this!


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Facebook: Masai Judah


Posted By: King Simeon
Date Posted: 26 November 2008 at 12:11am
... i was warned about valves when it comes to modern sounds... somthing about how they wouldn't do well with the upper bass frequencies hitting them, as in some feedback/resonance issues.... this is getting interesting now... and some East London history too!!
 
I know a few locals who want Forest Gate area to rise again with sounds/music...  


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https://soundcloud.com/king-simeon


Posted By: Masai
Date Posted: 26 November 2008 at 12:25am


Originally posted by King Simeon King Simeon wrote:


However, with the likes of Masai about the place... and the internet, these things might become easier to fix, and with more openess/sharing across Europe.... interesting.
 


You're not gonna make me the John Sargent of Speakerplans, iya!!!LOLLOL

You have man like Colin Bird, Mostech, Joseph Redemption, Russ D, and I'm sure there are a few others on here, that are techies. Certain ones, have told me from time, to throw my hat in the amp builder areana. It's still on my head, but with a slight lean an a tiltWink

Like I said, I don't tink I will build for joe public, but I am going to build units for myself and......

I will definately keep you posted, when I get someting together.

I'm going to offer services for repairs and servicing of music technology, pro audio, and guitar amplifiers. Just trying to sort out a new mobile number, then it's all go.

In the meantime, feel free to send me a pm, then we can go from there.

Blessed Love.


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Facebook: Masai Judah


Posted By: mykey
Date Posted: 26 November 2008 at 6:23am
Shocked
Originally posted by Masai Masai wrote:

I've just realised........

Nuff amp builders come from the endz (East London)!

Baracuda, Tubbys, Elvins, Mostech........

Anybody else?

You're right about the Swiss! Don't forget the Swedes, too! I know dem can build some good speaker boxes!

It does amazes me, how the features of the pre haven't changed in nearly 30 years. From when Bara came on the scene with his pre, JTS refined it, and there hasn't been much change since.

Same input channel featues, 10 band graphic eq (why?), parametric eq (yeah, right!), and how can I forget, the must have feature of all pre's - kill/ cut-out switches! With matching red, yellow, green, matching LED's and knobs. Yes, iya!LOL

Can anyone tell me when you last hear someone use their pre, to create a sonic delight?

The creativity it seems, has diminished. I think a lot of the music that the sounds play, also reflect this. Too be honest, if you have a pre with a flat response, and you're playing mainly UK style roots, it's gonna sound pretty lifeless. You see my brederns and sistrens, we are caught it viscous cycle. Sound system produces a certain sound, producers then try to replicate this sound on their productions, sounds play the tune, next producer trys to replicate this sound, etc.... Pure sub bass, stinging tops, not much in the middle. I'm sure if you looked at the graphic settings of most man's set ups, you will see the smiley face configuration. You put the mids up so that you can here the vocals, melody, chords, man start fi bawl!!!LOLConfusedCry

That's not to say that there are some good tunes being produced, but maybe it's a case that they are not being played because they are too 'musical'Confused or 'not hard enough'ConfusedConfused

I just wanna hear good tune, pon a good set. I wanna hear n feel the bass, but I want to hear the WORDS, the instruments, EVERYTING!!! I don't expect it to sound like a hi-fi, but if it did, is that such a bad ting? I don't my ears bleeding.

Audio electronics has been my profession for over 20 years. As soon as I mention Reggae, they (work colleagues) start to try and take the pee. It's only when the try n test me, they know that I'm not 'a typical Reggae man'. I remember one time when a ex colleague started to talk about about drum machines - Roland ones. When I started to correct him (which came first - 808 or 909, what was the difference between the two, etc.), he turned around to me and said 'You know your stuff - don't you? I don't want you to be offended by what I'm going to say (I thought 'here we go!'), but I've never come across a Black man like you' He started to comment about my knowledge, skills and workmanship, and how their isn't that many (Black men) in my field. In fact, we counted them, on one hand! I'm only talking about bredrens in technical positions (engineeers who can diagnois and repair to component level), in the music technology field and pro recording/ studio field. Not to say this hasn't changed, in the last few years.....

When they had a leading Reggae studio call up (they were a client), they use to roll up! You know what? I couldn't defend dem!!!

As a Nubian, I've had to deal with this ism n scism, as well as the other stuff. It's like someone who has studied to be a doctor, but also knows about alternative medicine that what used in his village by his elders....

Humble Tafari started a thread/ topic, several weeks back, where he stated that nuff of the UK sounds and sound men, are not doing enough in their communities (as well as some other stuff that he outlined). I agree with him. He made some good, and valid points

That's why I'm on a mission to educate the young people, with the knowledge and experience, that I have been Blessed to have gained, throughout the years. If one out of a hundred picks it up, it would be worthwhile. I'm going to do my best to help my Nubian young people. I won't and haven't excludeed others, but they are the ones, at the bottom of the pile right now. I'm working on a lot of guitar ampliiers lately, and there is a yoot who has shown some interest in electronics - the others don't give a toss! He will pop his head in my workshop and look over my shoulder and ask what's wrong with it, etc. I just tell/ show him, and sometimes show how bad some of this amps are badly put together (don't get me started on Mesa's!). He is of Anglo French descent.

Soooooo! Let's just keep tings on a positive heights! Yes, we should be critical of tings (bits of equipment in this case), and improve on tings, but let us not pick on something that has been a successful product for many years - just because you don't like it.
Better we just try to educate ones on how one feels sound systems should sound like, but remember that it's all subjective - he saysWink

If you was to look inside a Marshall amplifier, you would be shocked!

By the way, just look at the frenzy about the Bara on Ebay '£370'???Confused  'If I had the money I would pay a lot more for it'!!!ConfusedConfused

Now I wonder what ones would say, if they opened up that pre, to have a peek???Wink

Spectrum analyser at the ready, sah!!!

Me mother just ring to say she have some fish fi I n I, so me gawn!!!Tongue

By the way, this is not me novel. It was only meant to be a short reply! Just got carried away, while I was doing some other workEmbarrassed

Keep the positive vibes (and jokes) flowing, and keep the Fire burning!

Give Thanks and Praises!!!



 

<cough! Cough!!?

 

The4 boys from C1 (channel 1) went to the same school as me, they have never met me and still to this day I would like them to have the DubSub's

 

Born in West Ham

 

Lived Leytonstone, Leyton and forest gate

 

My first blues parties were at Cathall youth center at the age of 14, I was 6'1'' and they used to let me in 

 

First and last Pre I ever bought was an Elvin’s Pre with Kill switches

Had it for less than a month, it was either sell it or launch it at Elvin’s head

 

I actually liked the old git, so I sold it. The reason I sold it was because I was at a gig in a club in Hackney, and just as the DJ was doing a superb mix, the F'king Elvin mixer picked up a local Taxi signalShocked  an old story that I like to repeat from time to time

 

Was going to Elvin’s since I was 16, so dedicated was I, I used to get 3 bus's from Leytonstone. This is how long ago it was, does anybody remember when Elvin had a flap down counter that was flush up to the front door? He used to sit at his chair behind the counter at the shop doorLOL talk about Para

You were only allowed in if you had nough wad 

Does anyone also remember that cage he had in the back that was full if all the dear kit, wired to the mainsShocked wouldn't get away with that today

 

The Guitar shop a bit further down did the recons, and they wasn't very good at it

I think the giant Alsatian in the doorway would have been better at it

 

Fact; did you know that Elvin took on a spotty young ginger kid, that worked for him for a while, then stole the plans for his mixer and went out on his own

 

A few years later I was at Plasa, and this spotty young kid who now was about 21 had his own little booth at Plasa with this new MIXER Shocked yes you guessed it, kill switches

The kid made a fortune; they sold all over the world

 

Anybody remember the name of the Mixer?

 

Barracuda had a plain fronted shop at the Top of my road; the whole shop was grey fronted with no sine what so ever, even the windows were painted grey

 

Those were the days when the East end was buzzing with sound systems

 

My other favorite shop was Early Riser in Walthamstow, many of Saturday afternoons was spent in there sniffing all the new kit, that was where I first laid my hands on what was then the new fane Colossus 400

 

 


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......just all them hanging there like giant bananas.



Posted By: mskeete
Date Posted: 26 November 2008 at 8:07am
Originally posted by mykey mykey wrote:

<cough! Cough!!?

 

The4 boys from C1 (channel 1) went to the same school as me, they have never met me and still to this day I would like them to have the DubSub's

 

 
Are they in the country yet?
Could have sorted that out for you ages ago


Posted By: DC
Date Posted: 26 November 2008 at 9:13am
An API preamp... ? Wouldn't that be overkill for a soundsystem and a bit expensive ?
I just can't see the point in modding the JTS (without any disrespect, just my point of view). Joseph modded a JTS pre with valves on the output stage. So basicly you just add some harmonics and valve distortion to an already bad sounding (as some people say) unit.
 
Modding with better for audio suited components doesn't make a unit sound better per definition.
I have an old Soundtracs console and some people who own the same desk modded the original opamps in the desk. The desk is loaded with TL072's, they replaced them with the better spec'd NE5532 or even some people with Burr Brown opamps. After using the desk for a while and comparing mixes done before and after the modding. They all come to the conclusion that the modding made the desk sound clinical and all went back to the TL072's
That's the point ... some units have a certain character due to the components used.
Even a ceramic cap can make a difference in how a units sounds. Valves being used these days to give some character to a certain sound, basicly it's distortion and added harmonics.
Back in the day there's wasn't anything else available until the transistor made it's appearance. No one used valves anymore.....
So in the 1st place some people say they want a flat responce of a preamp but on the other side the want to have distortion and harmonics wich definatly don't give a flat responce. Mmmm... i just don't get it.
 
BTW didn't mad prof worked for Soundtracs and still have a Soundtracs Jade in his studio ?


Posted By: mykey
Date Posted: 26 November 2008 at 11:36am
Originally posted by mskeete mskeete wrote:

Originally posted by mykey mykey wrote:

<cough! Cough!!?

 

The4 boys from C1 (channel 1) went to the same school as me, they have never met me and still to this day I would like them to have the DubSub's

 

 
Are they in the country yet?
Could have sorted that out for you ages ago
gonna be 2 Dubsub's and 2 brute 45's in the country, January
Go see Trevor for a listen
you mite want to take a box of kleenex with ya, Shocked joke  


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......just all them hanging there like giant bananas.



Posted By: Deadbeat
Date Posted: 26 November 2008 at 7:43pm
DC, it's really not that simple with tubes.

But your premise is quite sound.


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Away on extended leave.


Posted By: DC
Date Posted: 27 November 2008 at 7:47am
Originally posted by Deadbeat Deadbeat wrote:

DC, it's really not that simple with tubes.

But your premise is quite sound.
 
Explain please !
 
I use valve gear in my studio set up and really that's what it does.


Posted By: mykey
Date Posted: 27 November 2008 at 1:56pm
Too slow?

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......just all them hanging there like giant bananas.



Posted By: Deadbeat
Date Posted: 27 November 2008 at 1:59pm
Have been a long time user of anything tube as well.

I can tell you that a 'flat response' in terms of FR is very achievable with tube amps.

You can get gear that has the 'classic tube sound' and still go for the goal of flat FR. The mystical tube sound is distortion as you know, obviously. Distortion is deviation (not FR) from the original signal. This is very dependent on design, actually. Automatically including tubes opens up a lot of doors. It is the types of distortion which matter in producing the trademark sound (whichever type you want). The way such distortion types interface with the brain is also part of it. Even order harmonics are perceived as warmth; very roughly speaking. The most common tube design with this in is the SET. You can also have very low distortion tube amps.

Another nice example is the Japanese vs American tube amp design philosophy. When going for the same type of design for the example's sake, the Japanese amp will choose the lower power lower distortion route, and the American one the opposite.They can both have roughly the same FR.

It is up to the choices of the designer and the type of design that make a tube device sound.


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Away on extended leave.


Posted By: Masai
Date Posted: 29 November 2008 at 10:32am
Yes Mykey!

I'm a Hackney man. Then we up sticks in '79, and move out to the country - LeytonstoneWink

I use to walk up the High Rd and look in Holiday Muisc, and especially Freedmans. They has a Synare 3 in the window. Cost £129.99 I think. The only good ting about Leytonstone I thought - at the time.

Well, I'm not gonna say nuttin' 'bout Elvins equipment, or prices!Wink

As for the ginga, I think it was just before my time there. I heard rumours at the time. Wasn't it a Soundlab unit?

DC - Yes, I've heard the Soundtracs story (TL072) before. Even though TL072, NE5532, have the same pin-out configuration, and can be interchanged to some extent, they are quite different devices. TL's are JFET devices (high input impedence, low current current dissipation, etc), NE's are bipolar (good at accepting and driving low impedances, lower noise - under certain conditions, etc). Other things come into play, of course. The design of the circuit, quality of components, psu, etc.

I can't answer your question about Mad Prof/Soundtracs link.

Deadbeat - I more or less agree, with what you say about valves/tubes.

The Japanese and American differences go much deeper.....

Most traditional Japanese/ Oriental music, contain a lot of mid to high frequency content. Delicate strings, percusion, and metalic sounds. American traditional music contains a lot bass to mid content. This has transfered itself down to all areas of audio design.

Japanese analogue synthersisers (Roland, Korg, Yamaha) were known for producing mainly delicate and swirlly sounds. American analogue synths (Moog, Sequential, APR) were known for producing bass, aand fat sounds. Same goes for speakers, microphones, phono cartridges, amplifiers, mixers, etc.

Who remembers the advertising war between Mackie and Soundcraft? Too be honest, it was more about Mackie running down the 'Great Britsih Eq', which was inherent to Soundcraft consoles.

British ears lay in the middle of the two. Maybe that's why the UK are still producing top class gear. SSL, Neve, Focusrite, just to name a few.

By the way.......

I got some pics of a nice unit that appeared on my bench, this week. Never seen one before, so I will try n post a pic up.....

Give Thanks

Masai




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Facebook: Masai Judah


Posted By: Maarty
Date Posted: 01 December 2008 at 8:17pm
This is a great topic, good to see people finally been a bit more open regarding the pre-amp debate. For too long our UK brethren have been stick-fast and quite defensive regarding the use of such equipment. Something I do understand considering the history and development of sound culture within the UK. But it has became so entrenched within UK reggae culture that even bridging the subject was a frightening prospect for anyone, let alone an outsider. Generally I've kept well away from such debates.


Posted By: RENSAAB
Date Posted: 02 December 2008 at 8:44pm
I love pre-amps and the emotions they can stir up between sound men!

"...you preamp never tune right from from it build because my tops sound "tschh tschh" and yours sound "tsss tsss..." LOLLOL

Sound argument between Blacka Dread and King Tubbys. Laughed so hard i nearly dropped!




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"The secret of the Scoop, what a wonderful piece of Science" - Tony ASS.

"when the amplifier and voice coil are in complete synchronicity there is magic" - A Well Respected Amp Guru


Posted By: Joseph Redhemption
Date Posted: 14 December 2008 at 7:54pm
Some teasing before new tests and tweaking



Posted By: mskeete
Date Posted: 14 December 2008 at 8:19pm
how will I sleep tonight...


Posted By: Masai
Date Posted: 15 December 2008 at 2:10pm
Originally posted by mskeete mskeete wrote:

how will I sleep tonight...
 
LOLLOLLOLLOL
 
I've got some Calpol here, if you need it!
 
Me have a new name fi him - Hot Rod Joe! The fastest amp mod/tweaker inna di area!!!
Pow, pow! Or should that be bang, bang..... Joke me a make, iya!
 
Can't wait to see your the finished products and a full report, Joseph.
 
Dis is more thrilling then 'Hereoes' to blouse n skirts!!!


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Facebook: Masai Judah


Posted By: wasup
Date Posted: 15 December 2008 at 3:37pm
Yes keep up the works!! keep ur intention straight!

mind you isnt that how some speaker company start out EXPOSE everyones secrets but now them are very secret about their own!beware lol
more time
andy


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a butterfly can cause an whirl wind!
Plant a sead and JAH WORKS BE DONE!!


Posted By: Rootsdriver
Date Posted: 15 December 2008 at 11:21pm
Hey Mark,
seeing that you can not sleep anyway, you should have some spare time to clear your inbox.
 
Cheers Chris


Posted By: Joseph Redhemption
Date Posted: 24 December 2008 at 7:28pm
Ok, finally I got the JTS finished with my new linear crossover.


And replaced the power supply with my new one. The original one was no more enough to drive the opamps.


First the phase timing test
This is with the original xover
Bass and Mids out at 212Hz


And this is with the new one.
The plot speaks for itself
Bass and Mids out at 140Hz.
I changed the crossover point a little lower.


Now Mids and Highs at 4.3kHz of the original one
80uS of delay


And this is the new one
Mids and Highs at 5Khz
20uS of delay


This is the frequency response taken at tape out with all pot at 12 o'clock (exept parametric mids full clockwise) from the original xover.


And the new one with same settings


I'm very happy with these results.
This preamp will be used in january in Geneva with a special guest from UK(The special guest sells preamps on behalf of JTS).
This will be the real test.

Soon I will publish the results of a Mostek 4 way.
I can tell you now that the build quality is 10 time worser than JTS. This doesnt mean it sound bad.

Raspect
Jo






Posted By: russ d
Date Posted: 24 December 2008 at 8:59pm
ha ha... the `real test`, hmm maybe i will make it sound crap because its all different now !...ha ha.... anyways, it`ll be interesting to hear... now if the eq can sound anything like the SSL x-rack eq i just got for the studio, then you`ll see me smiling, so get to work joseph ! 

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Disciples on I-Tunes.

Disciples on Bandcamp: http://russdisciples.bandcamp.com/

Facebook: russ disciple

Youtube Channel: http://www.youtube.com/user/sargantbrown?feature=mhum


Posted By: Rootsdriver
Date Posted: 27 December 2008 at 12:36pm
This is turning into a really interesting thread. It`s one thing finding weak spots on any product but it`s another thing when improvements go along with it. Really nice job!!
Are you going to add a "Pimp my Pre" programm too or sell mod kits?
 
Quote Jo:
Soon I will publish the results of a Mostek 4 way.
I can tell you now that the build quality is 10 time worser than JTS. This doesnt mean it sound bad.
 
Really waiting for this report. I`d say that most electrical products are not really meant to be opened as most do not know what they see anyway. I am more interested into the functionality but on the other hand, if this will result in improvements again, nothing wrong with that.
 
Keep it coming.


Posted By: wasup
Date Posted: 27 December 2008 at 4:34pm
Originally posted by Joseph Redhemption Joseph Redhemption wrote:

Soon I will publish the results of a Mostek 4 way.
I can tell you now that the build quality is 10 time worser than JTS. This doesnt mean it sound bad.

Raspect
Jo
 
Well dont forget some Photos highlighting the bad build quality! please.............


-------------
a butterfly can cause an whirl wind!
Plant a sead and JAH WORKS BE DONE!!


Posted By: Joseph Redhemption
Date Posted: 27 December 2008 at 4:45pm
Raspect,

Rootsdriver - The idea of kits is not bad I will look into this.

Wasup - You will be amazed by the picture, never seen that even in those nearly 70 years old pre that where hand wired to a much higher quality.

Bless
Jo


Posted By: PISSHEAD
Date Posted: 27 December 2008 at 4:52pm
You can see the inside of mostec preamps on his webpage.

heres the link http://mostec.co.uk/electronics/preamps/4-way/4-way-preamp-build.htm - http://mostec.co.uk/electronics/preamps/4-way/4-way-preamp-build.htm



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The 'drunken master' strikes again.


Posted By: wasup
Date Posted: 27 December 2008 at 6:20pm
Originally posted by PISSHEAD PISSHEAD wrote:

You can see the inside of mostec preamps on his webpage.

heres the link http://mostec.co.uk/electronics/preamps/4-way/4-way-preamp-build.htm - http://mostec.co.uk/electronics/preamps/4-way/4-way-preamp-build.htm

Nice link ! Looks pretty good to me!Would explain why HE has the BEST SOUNDING PREs .lol.................
 Mostec doesnt come over as anyone who would do HALF WORK!
again thanx
andy
 
Joseph what do you mean? Whats wrong with them? I hope it isnt a sales PITCH for that guy your hiring ! The one who is selling the other make??
Maybe u have an early one before the print was made by a machien! Mind you even then !lol
 
 


-------------
a butterfly can cause an whirl wind!
Plant a sead and JAH WORKS BE DONE!!


Posted By: Joseph Redhemption
Date Posted: 27 December 2008 at 10:20pm
First I also tought it was a prototype but after contacting the owner - who is by the way very satisfied with the sound but not the construction quality ex. cheap pots - it is his third Mostec pre and this one is of his current production with the machined board.
What I mean by poor build quality is the solders. Example : if you need to solder a copper wire into a board first you put solder onto the wire then put it thru the hole and solder. But I found a wire that has no solder on it but plenty of solder around the wire on the board - picture will come - and you can just pull out the wire. How it worked until now is miracle.
 
And the wires go everywhere like spaghettis - why not attaching them together?
The difference between JTS and Mos is that JTS you know its a finished product since years and with Mos plenty parts are flying like if you do prototyping and the quality of the solders are really very poor.
But once again this doesnt mean nothing at all to the sound of the pre but only the reliability over years.
 
Oh yeah and by the way the owner told me that the first pre he had from Mostec the wires where just wrap around pins with no solder!!!
 
And Wasup when you open a JTS it is clean. Really nice building work. No parts flying around. When you look Mostec pre at the picture from the link above its a real mess.
 
Sorry Mos but shame on you.


Posted By: Rootsdriver
Date Posted: 28 December 2008 at 12:50pm
That brings up memories.
About 20 years ago I had to learn the "wire wrap" technique. The wrapping was handled by something like a pistol. Put the wire in the pistol, place it on the pin and shoot. :-) With the right wire the connection was just as good as soldering but it was only used for fixed pins. Loose components like resistors etc. need the soldering for fixing.
I assume using the wire wrap stuff for connections on pots and buttons which are held in position by itself, is perfectly okay.
 
Component quality.
This topic always pops up every now and then. This only applies to movable parts anyway so it would be only for pots and switches. Of course there can be differences in quality and price but their lifetime also depends on how and how often you use them. Changing them just takes a few seconds. Spending a lot more on high class components are no guarantee that nothing will happen and using middle class stuff does not say that they will break. I`d always go for middle class stuff.
 
Cable routing?
HHmm, I guess this is more or less left for the builder to decide. You can spend hours on this if you didn`t take care of it right from the beginning. As long as it doesn´t effetc functionality, most customers will not care. I guess it all brings pros&cons. A proper routing either by channels or just bundled wires looks nicer but if you are trying to find a mistake or need to do some adjustments, it can turn into a nightmare, let alone trying to put everything into back place when finished. Try to find an electronic prob on a new care. The replace the complete cable tree as nobodys can open it and put it back together again.
 
Let`s see some graphs. I`d say cable routing a "nice to have" but really low priority....but that`s just me.
 
Still, you obviously know what you`re doing on the electronic side so if there is something to improve, keep going.
If my upcoming Mostec preamp will do what I hope it will, it`s all good with me. :-) 


Posted By: Rootsdriver
Date Posted: 28 December 2008 at 1:40pm
Sorry for the grammar. :-) Next time I use the spell checker before posting.


Posted By: tweeter box
Date Posted: 28 December 2008 at 6:17pm
we have a spell checker?
 
my mostec runs beautifully, the sound is excellent, the kills are 100% im very happy with all its features
 
these changes/upgrade graphs etc that you show are they noticable to the human ear?
 
coz my pre sounds lush man!
 
keep up the good work Mostec Thumbs Up
 


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PRECISION SOUND SYSTEM.

Feeding the peoples needs for Roots Music.

Strictly premium grade reggae and dub steppers from the early 70's to present day.


Posted By: DC
Date Posted: 29 December 2008 at 8:27am
Originally posted by russ d russ d wrote:

ha ha... the `real test`, hmm maybe i will make it sound crap because its all different now !...ha ha.... anyways, it`ll be interesting to hear... now if the eq can sound anything like the SSL x-rack eq i just got for the studio, then you`ll see me smiling, so get to work joseph ! 
 
Yes Russ, now you have to reproduce that dip around 200 and shift that peak back to 50. You bring your mini pre Smile?
 
now that would be great...an SSL pre, hi end power amps and some scoops loaded with PMC designed 18"s... and then run some tune from a garrard deck.


Posted By: Rootsdriver
Date Posted: 29 December 2008 at 11:11am
Some years back I had a car which was pulling to the left but I had no money to fix it. I kept driving it like this for 3 years. When I finally had some money, I got it fixed - and almost hit a wall on my way home. ;-) Guess it all comes down to what you are used to.
 


Posted By: Joseph Redhemption
Date Posted: 29 December 2008 at 10:21pm
Tweeter Box - For sure you will hear the difference. Like on your pre turn one of the graphic eq pot from the 12oclock pos to say 3 or 4 oclock and I bet you will hear.

DC - Why run a tune on a Garrard? It must be a Swiss Thorens TD124!!! Lol


Posted By: Calculus
Date Posted: 30 December 2008 at 6:05am
you should really speak to the makers of these pre's about the mods you're making and maybe get them to make a upgraded version with your input... however that would mean they'd have to be humble enough not to take it as a insult to thier work. But if everyone reads this they may not have a choice.


Posted By: DC
Date Posted: 30 December 2008 at 8:13am
Originally posted by Joseph Redhemption Joseph Redhemption wrote:

Tweeter Box - For sure you will hear the difference. Like on your pre turn one of the graphic eq pot from the 12oclock pos to say 3 or 4 oclock and I bet you will hear.

DC - Why run a tune on a Garrard? It must be a Swiss Thorens TD124!!! Lol
Big smile


Posted By: russ d
Date Posted: 30 December 2008 at 10:57am
Originally posted by Calculus Calculus wrote:

you should really speak to the makers of these pre's about the mods you're making and maybe get them to make a upgraded version with your input... however that would mean they'd have to be humble enough not to take it as a insult to thier work. But if everyone reads this they may not have a choice.


they always have a choice !... the mods dont do anything without the pre in the first place, any new / upcoming soundman will still have to buy into having a pre, or going a different route (which is another discussion in itself), at the moment you`ve little choice but JTS or Mostec as the most easily available of pre-amp suppliers, so they will still sell, or sounds will do without pre-amps, those are the choices !....

it will be the buyers choice wether he wants his new pre modded or not (btw, such mods will void any garauntee by the pre builder), for those with old pre`s, well there`s nothing wrong with going to joseph for his mods, or if he sells kits for diy-ers, this sort of thing is maybe part and parcel of your sound system career, upgrading and such... the same happens with many a higher end studio gear, with people upgrading valves, opamps and other components, its nothing to do with the original manufacturer, who will continue making thier equipment as is.



-------------
Disciples on I-Tunes.

Disciples on Bandcamp: http://russdisciples.bandcamp.com/

Facebook: russ disciple

Youtube Channel: http://www.youtube.com/user/sargantbrown?feature=mhum


Posted By: mskeete
Date Posted: 30 December 2008 at 11:05am
Originally posted by Calculus Calculus wrote:

you should really speak to the makers of these pre's about the mods you're making and maybe get them to make a upgraded version with your input... however that would mean they'd have to be humble enough not to take it as a insult to thier work. But if everyone reads this they may not have a choice.
 
Well, I like to think of myself as a humble person (sometimes too humble).  I can (and do) talk hours with other builders. Jo's main complaint about my work seems to be some soldering and some pots. I will comment on that but not yet
 
The thing with some "upgrades" is you can quickly reach a point of diminishing returns
How many people can go a session (not home listening) and hear the difference between a phono stage built around 1 opamp or 2 opamps, serires feedback or shunt feedback


Posted By: King Simeon
Date Posted: 30 December 2008 at 11:54am
.... well i certainly can.....
 
And i refuse that my music be played through anything but 2 opamps with series feedback.... and people must have red, gold and green silk ear plugs, otherwise it just wouldn't have the same effect.... ConfusedLOL
 
It's a great excersize all this... but thats all it is. In amongst the science it's a Daily Mail style thread, un-covering the 'Truth' about 'so called' pre amp builders in London, watch out guys, i think i saw Roger Cook at the last session, snooping about.... he'll be bursting in on you Mskeete to ask some uncomfortable questions!!LOLLOL   


-------------
https://www.facebook.com/KingSimeonSound?ref=stream     
https://soundcloud.com/king-simeon


Posted By: Rootsdriver
Date Posted: 30 December 2008 at 12:28pm
Hahaha,
I could feel the ice geting thinner on this one. I assume that most preamp experience is with the UK soundmen as they`ve been handling them for ages. They learned how to make them work best. The rest of us is just trying to catch up. 

Over here, besides from a handfull of people who started earlier, we are just starting to look into things. Trying to understand how things work. The preamp is kind of a black box with a good portion of mystery around it. Everyone knows what filters are being used etc. but that`s just theory. If you want to know what a black box is doing, put something in and see what comes out. Looking at the output you can maybe tell what it is doing but not how it`s done. Joseph took it one step further and I don`t see anything wrong with that. I personally don`t have the chance to run such test....as the preamp availability is not as good as mentioned by Russ, hahaha.....but I`d love to run the same test. Just to have a go.

All this is just part of the learning process. Could these results end in a more precise preamp? Maybe. Will this make a good sound session? Definitely not! 

I guess the issue with upgrading is because this whole thing is soo tiny. A Russ mentioned there are only very few building preamps so there is no real competition. As a customer you can either take it or leave it. 
If other "markets" were working in the same way, we would all still be driving a VW Beetle and our mobile phones would still have the size of a brick.

Just take it as a technical test result. Of course the pre builders can ignore it but what`s the benefit? The results might even be wrong or limited only that one tested unit. There might even be a reason to have it that way.

P.S: My biggest prob with a pre is - actually getting one. ;-)

Wishing you all a healthy and humble start into 2009. I`ll be running a private session tomorrow playing all night, trying to make it joyfull for everyone even without a preamp. It`s all about the music, isn`t it?

Chris



Posted By: tweeter box
Date Posted: 30 December 2008 at 12:59pm
Originally posted by King Simeon King Simeon wrote:

.... well i certainly can.....
 
And i refuse that my music be played through anything but 2 opamps with series feedback.... and people must have red, gold and green silk ear plugs, otherwise it just wouldn't have the same effect.... ConfusedLOL
 
It's a great excersize all this... but thats all it is. In amongst the science it's a Daily Mail style thread, un-covering the 'Truth' about 'so called' pre amp builders in London, watch out guys, i think i saw Roger Cook at the last session, snooping about.... he'll be bursting in on you Mskeete to ask some uncomfortable questions!!LOLLOL   
 
LOLLOLLOL


-------------
PRECISION SOUND SYSTEM.

Feeding the peoples needs for Roots Music.

Strictly premium grade reggae and dub steppers from the early 70's to present day.


Posted By: DC
Date Posted: 30 December 2008 at 4:18pm
 
To build a really good sounding preamp, Try this for EQ buildingblock. More of those schematics around on the net.


Posted By: bitzo
Date Posted: 30 December 2008 at 5:17pm
sorry but.... this only an equalizer with kill switch, I mean it don't have 3 output (bass, mid, high)


Posted By: Joseph Redhemption
Date Posted: 30 December 2008 at 5:51pm
Mostec on the test bench

Before I publish the audio test ands plots here are some picture from the inside.

Here on the top left of the board is a wire that seems to be soldered but its not if you pull the wire it comes out. On the picture the colors are not true but the wire is still copper color.
One of the first technique you learn when you study electronics is to put solder on the wire before soldering it to anything else. This for two reason - first to avoid oxidation of the copper wich causes false contact and second to ensure solder makes full contact with the wire thus ensuring as less possible solder resistance.
The wire is also not isolated. You can see the shielding coming out between the white and gray part of the wire. If this touches some supply voltage or opamps output...Confused


On this one you see the xover outputs with blocking caps.
So whats wrong? In absolute nothing but as electronician I just can't believe that is the current production. It looks and is constructed like a prototype.
First why can't this cap be on your proffesionnal boards? And by the way why electrolitic caps?
Second why can't you put some heat shrink tube instead of tape that will inevitabely and slowly fall off? Perhaps you sell your pre's too cheap and you're out of money for spending 30pounds for heatgun?Wink



Here on the top middle where the red wire are soldered you can see a nice antenna.
I think its used for listening to Shaka or Rodigan on KISS FM.
Very nice feature for an pre LOL


Why make expensive machine drilled board by profesionnal company and the bend the pin of the cap around it?


Perhaps I'm too demanding but I'v not learned electronic building of this kind.

The owner of this pre gave it to me because he broke one plastic pot. He asked me to put some metal pots and he sayed he was not satisfied with the build quality. I totaly agree. Why sell it so expensive when its so cheap quality?
This kind of building can explain why this unit is so noisy. With all kill switch off you hear the wind blowing thru your speakers - the wires fly around, antenas, flying components,....
The JTS in comparision is dead quiet.
Even worser I approached my laptop PSU accidentaly near the side of the Mostec pre and I heard it thru the speakers. That because of the aluminium casing wich is not as good as steel against EMI/RFI pertubations. JTS use steel like Lincoln.

I'm just talking about the build quality wich is not at level.
But I like the modularized design, the layout and the VU meters

Soon some audio tests

Raspect
Jo


Posted By: Masai
Date Posted: 30 December 2008 at 7:00pm
Well, kiss me neck back!!!!!!

No long ting but looking at the pics of mans workmanship, I think it's a case of the pot calling the kettle black!!!!

The blind leading the blind, also springs to mind.......

Just going off on a tangent......

I would like to Bless up Channel One and Touch Above, for a nice lickle sesion down Silent Whispers, last Saturday. It seems like a nice place for sounds with two good stacks. I think ths would help to bring up small/medium sounds. I hope promoters and the people would go out to support and encourage, such a session.

So long as they all used a Mostech pre which was pimped up with valves n ting by Joseph 'hotrod' Redemption, it would be irie......

Give Thanks and Praises - everytime


-------------
Facebook: Masai Judah


Posted By: Rico
Date Posted: 30 December 2008 at 7:36pm
Originally posted by Joseph Redhemption Joseph Redhemption wrote:

Tweeter Box - For sure you will hear the difference. Like on your pre turn one of the graphic eq pot from the 12oclock pos to say 3 or 4 oclock and I bet you will hear.

DC - Why run a tune on a Garrard? It must be a Swiss Thorens TD124!!! Lol


Whats the joke about those two players?
are they weack?

I only know that shaka is using a Garrard...




Posted By: Rootsdriver
Date Posted: 30 December 2008 at 8:44pm
That`s not the kind of wire wrap I had in mind. That`s wild


Posted By: DC
Date Posted: 31 December 2008 at 8:18am
Originally posted by bitzo bitzo wrote:

sorry but.... this only an equalizer with kill switch, I mean it don't have 3 output (bass, mid, high)
 
Obviously you can't read schematics. There's no killswitch. And i said use it as building block.
This is one of the best tube EQ's around.


Posted By: PISSHEAD
Date Posted: 31 December 2008 at 9:38pm
Have a look at this eq looks like a space age pre amp.  Just scroll down and check out the additional pics you can see the various roll off freq.

http://cgi.ebay.de/Klein-und-Hummel-UE-1000-RARITAT-VERY-RARE-TOP_W0QQitemZ170286900979QQcmdZViewItemQQptZStudioequipment?hash=item170286900979&_trksid=p3286.c0.m14&_trkparms=72%3A1229%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 - http://cgi.ebay.de/Klein-und-Hummel-UE-1000-RARITAT-VERY-RARE-TOP_W0QQitemZ170286900979QQcmdZViewItemQQptZStudioequipment?hash=item170286900979&_trksid=p3286.c0.m14&_trkparms=72%3A1229|66%3A2|65%3A12|39%3A1|240%3A1318




-------------
The 'drunken master' strikes again.


Posted By: russ d
Date Posted: 31 December 2008 at 10:06pm
to be pedantic, its a mono vinyl cutting / mastering equalizer, not a pre-amp, and wont do the job of one !... its from the early 70`s, weighs in at around 25kg... as an equalizer, if working good, then it should sound good, a bit extreme for any sound system use tho`, and expensive !

-------------
Disciples on I-Tunes.

Disciples on Bandcamp: http://russdisciples.bandcamp.com/

Facebook: russ disciple

Youtube Channel: http://www.youtube.com/user/sargantbrown?feature=mhum


Posted By: mskeete
Date Posted: 01 January 2009 at 12:00pm
Originally posted by Joseph Redhemption Joseph Redhemption wrote:

Mostec on the test bench

Before I publish the audio test ands plots here are some picture from the inside.

Here on the top left of the board is a wire that seems to be soldered but its not if you pull the wire it comes out. On the picture the colors are not true but the wire is still copper color.
One of the first technique you learn when you study electronics is to put solder on the wire before soldering it to anything else. This for two reason - first to avoid oxidation of the copper wich causes false contact and second to ensure solder makes full contact with the wire thus ensuring as less possible solder resistance.
The wire is also not isolated. You can see the shielding coming out between the white and gray part of the wire. If this touches some supply voltage or opamps output...Confused

 
That first picture is a bit "out of context". Looks like you've removed the xover board and all the parametrics and have 2 of the parametric boards hanging over the LED meters
 
If that's how I soldered that connection then there's no defending that. As for the little bit of exposed shielding, the wire is part of a double screened wire. it's not likely to touch a supply rail or opamp output. The supplies are short circuit protected and so are the opamps
 
Anyway, you'll be pleased to know that already have a new version of that circuit board with input / output connectors as well as power connectors (that one only has power connectors). I'll post a picture if you really want to see it
 
Originally posted by Joseph Redhemption Joseph Redhemption wrote:


On this one you see the xover outputs with blocking caps.
So whats wrong? In absolute nothing but as electronician I just can't believe that is the current production. It looks and is constructed like a prototype.
First why can't this cap be on your proffesionnal boards? And by the way why electrolitic caps?
Second why can't you put some heat shrink tube instead of tape that will inevitabely and slowly fall off? Perhaps you sell your pre's too cheap and you're out of money for spending 30pounds for heatgun?Wink

There's a simple reason that those caps aren't on the board which I don't really need to go into because as you have said, nothing is actually wrong with that. A few components mounted off board doesn't  = prototype. I've seen JTS other preamps with a few components mounted off board but you didn't call them prototypes.
 
As for electrolytics in the signal path, I've seen that all all sorts of equipment. We can have endless debates about that
 
Originally posted by Joseph Redhemption Joseph Redhemption wrote:


Here on the top middle where the red wire are soldered you can see a nice antenna.
I think its used for listening to Shaka or Rodigan on KISS FM.
Very nice feature for an pre LOL

That wire's too short to pick up KISS FM
 
Originally posted by Joseph Redhemption Joseph Redhemption wrote:


Why make expensive machine drilled board by profesionnal company and the bend the pin of the cap around it?


Perhaps I'm too demanding but I'v not learned electronic building of this kind.
No big deal here. Must have been out of stock of some small caps. I used some bigger ones
That wire hasn't and isn't going anywhere
 

Originally posted by Joseph Redhemption Joseph Redhemption wrote:


The owner of this pre gave it to me because he broke one plastic pot. He asked me to put some metal pots and he sayed he was not satisfied with the build quality. I totaly agree. Why sell it so expensive when its so cheap quality?
This kind of building can explain why this unit is so noisy. With all kill switch off you hear the wind blowing thru your speakers - the wires fly around, antenas, flying components,....
The JTS in comparision is dead quiet.
Was this from the tape output of both units? if so, I can explain the difference
In most of the sessions I've been to, I don't notice a great amount of bakground noise out of my preamps (except one particular sound but that's another story)
 
I've heard JTS (the sound system) with some large background noise (Played against touch above) and I seem some other sounds that use noise gates just before the amps because their set is so noisy
 
Originally posted by Joseph Redhemption Joseph Redhemption wrote:


Even worser I approached my laptop PSU accidentaly near the side of the Mostec pre and I heard it thru the speakers. That because of the aluminium casing wich is not as good as steel against EMI/RFI pertubations. JTS use steel like Lincoln.
You got me thinking about that. I did some searching on the net and then checked my case supplier and notice they have some EMI/RFI shielding case options. I'll speak to them on Monday. The use of aluminium cases was never about cost. I don't need to sell preamps to pay my bills
 
Originally posted by Joseph Redhemption Joseph Redhemption wrote:


I'm just talking about the build quality wich is not at level.
But I like the modularized design, the layout and the VU meters

Soon some audio tests

Raspect
Jo
Looking forward to the audio tests (good or bad)
you like the VU meters?
I got about 300 sitting here pre built. I'll sell you some Tongue
 
 
somebody bring me a gun....
 
 
Heat gun of course


Posted By: tweeter box
Date Posted: 01 January 2009 at 1:49pm
HAPPY NEW YEAR TO EVERYBODY IN THE ROOTS AND CULTURE FORUM
 
HAS BEEN A VERY EDUCATIONAL YEAR
 
ALL THE BEST FOR 2009
 
Clap


-------------
PRECISION SOUND SYSTEM.

Feeding the peoples needs for Roots Music.

Strictly premium grade reggae and dub steppers from the early 70's to present day.



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