Jah Tubby preamp mods continued

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|66%3A2|65%3A12|39%3A1|240%3A1318




Edited by PISSHEAD - 31 December 2008 at 9:55pm

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...

Raspect mskeete

I really apreciate your honest replies. Raspect in every aspect.

The readers will make their own opinions about.

I will chase this noise issue and keep you informed. Because I did the check the individual xover output and the noise is mainly on the hi-mid and the highs. Bass and lo-mid are quiet.

About the caps as you say this is a great debate but theres defenitly an answer.
Electrolitycs cap have a greater - 5 to 10 times - impedance thus creating problems in the linearity of frequency response and greater distortions.
Its not because you saw it in many lo-cost or so called consumer electronics that this is a good thing.
When I look in some of my gear - Urei 2-1176, Thorens PR15, Aura Evolution, Dynacord Eminent1 and Exellent - I don't see any electrolityc on the output but only quality film caps.

About the flying components your right in JTS there are a few. But in yours there are many and not like JTS where the components are between a board and a switch. They cannot move.
I will not say by yours it will move nor I would say it will not.
In my proffesionnal route I had to design and build tools for the oil and gas that goes down hole. There are many vibrations and shock and I saw many times broken wire or components that moved. A wire or a component that is not firmly attached will brake its only a matter of time.
For the shielding I can only strongly suggest you to use steel and to cut all of these antennas. Once again in my proffesionnal journey I had to develop and build - not alone-  a chirurgical simulator and we had to pass EMI/RFI tests. We did go to a anechoidal room and we where really surprised how sensible it can be to make it EMI proof. Every little hole in the case or bad shielding inside where the entry point of the pertubations.

Thank you anyway for taking time to reply to my remarks. Big Up

Raspect.

Jo




Edited by Joseph Redhemption - 01 January 2009 at 7:12pm

mostecs soldering iron !!

mostec gets to grips with latest pre-amp build....

Greetings,

Edited by joseph - 11 January 2009 at 9:45am