Speakerplans.com Homepage
Forum Home Forum Home > General > Amp Forum
  New Posts New Posts RSS Feed - bss epc 740/780
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

bss epc 740/780

 Post Reply Post Reply Page  <1234>
Author
Message Reverse Sort Order
madboffin View Drop Down
Old Croc
Old Croc


Joined: 03 July 2009
Location: Milton Keynes
Status: Offline
Points: 1537
Post Options Post Options   Thanks (0) Thanks(0)   Quote madboffin Quote  Post ReplyReply Direct Link To This Post Posted: 05 October 2013 at 8:58pm
The power supply design was highly innovative too.
Back to Top
SMP View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 March 2013
Location: East London
Status: Offline
Points: 1226
Post Options Post Options   Thanks (0) Thanks(0)   Quote SMP Quote  Post ReplyReply Direct Link To This Post Posted: 05 October 2013 at 8:55am
very nice kit run in class AB with a higher than usual bias so that they run in Class A mode for significantly more than the usual class B such as Labgruppen and others

Cannot remember now if it was fixed high bias or a sliding bias that was used. The other thing that is very different about these is the output stages most amps use a lesser amount of high wattage devices BSS turned it on it head and used lots of lower power devices this amongst other things has the benefit of reducing output impedance of said stage so improving Damping factor which is largely a product of the ratio of load impedance to output stage impedance as it contained lots of devices which in parallel exhibit a much lower value

it does have the disadvantage of giving you more of said devices to drive with there increased Gate capacitance but not difficult to address this issue though many other MOSFET it is a common
 issue not to address this at all the list for this is pretty endless  but C-Audio and many of that type are the culprits using Pseudo "class A" drive circuits to drive them so that cheaper transistors can be used and reliability increased but to the detriment of performance

Sadly very few audio designers fully grasped the principles of MOSFET use for high power Audio Amps but BSS and of course Adyton used them to good effect though the latter used them in a hybrid output stage (Bi-MOS)
so now we are mostly back to Bipolar devices as the impetus for MOSFET development was not continued for audio but they do many other tasks such as control the Motors on your Tube Train and many other power control tasks many SMPS contain MOSFET switching devices or it#s brother the IGBT such as QSC

perhaps i will have look at the service files think still have some on file at the old workshop jog my memories
but all in all super kit often ponder buying some for my collection of old amps coz they really were a wonderful ground breaking design

Back to Top
madboffin View Drop Down
Old Croc
Old Croc


Joined: 03 July 2009
Location: Milton Keynes
Status: Offline
Points: 1537
Post Options Post Options   Thanks (0) Thanks(0)   Quote madboffin Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2013 at 12:12pm
Quote when they were released a hi-fi magazine tried some out to see if the claim that a pa amp was suitable for the studio could possibly be justified, the verdict was: sell everything else, buy bss epc!


That's true, my ATC passive monitors sounded wonderful when I tried running them off an EPC780. A direct comparison with a Macrotech 2400... oh dear oh dear...

Back to Top
mk2_ginger_biscuit69 View Drop Down
Old Croc
Old Croc


Joined: 03 November 2008
Location: Brighton
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote mk2_ginger_biscuit69 Quote  Post ReplyReply Direct Link To This Post Posted: 28 September 2013 at 9:39pm
Originally posted by james folkes james folkes wrote:

the electrical power converter series of amplifiers were, at the time of making, some of the most ambitious pa amplifiers ever built. packed with innovative technology, there is an awful lot of stuff crammed into those 2u chassis, they do indeed weigh a ton too. there aren't that many people who even know how, let alone enjoy repairing them, but i totally lust after them nevertheless. i wanted to get a pile for the martin modular rig from brit row, but they'd all gone before i got the cash together.

by modern standards they aren't insanely powerful, a bit over 1k a side into four ohms for the 780, but the spec is absolutely off the charts compared to almost anything you can buy today (like damping factor >1800), they control cones very well. at lower power levels they operate at pure class a topology, but then gets to class a-b as it gets above 20 something watts a side. as suitable for the studio as they are for the stage, they even come with a fan defeat switch to keep them hush-hush, no worries about overheating though as they have excellent protection circuits and you can keep an eye on the temperature with handy gauges on the front. behind the electrostatically charged dust filters you'll find little switches that configure the protection systems for 4 or 2 ohm usage.

when they were released a hi-fi magazine tried some out to see if the claim that a pa amp was suitable for the studio could possibly be justified, the verdict was: sell everything else, buy bss epc!

the manual is available from the bss website, it makes great reading. well, i think it makes great reading, but then again i do read operating manuals as a leisure activity.

james.



looks like someone has been stealing your words James!!

http://www.ebay.co.uk/itm/BSS-epc780-amplifier-4-2-ohms-/330921325379

sorry for the bump, been shopping for one to play with....


Edited by mk2_ginger_biscuit69 - 28 September 2013 at 9:41pm
''Remember that the object of a subwoofer is to enhance the output of your main speakers, not overpower it''

''Dubstep - an elongated electronic fart''
Back to Top
4D View Drop Down
Old Croc
Old Croc


Joined: 13 November 2008
Location: Winchester
Status: Offline
Points: 4255
Post Options Post Options   Thanks (0) Thanks(0)   Quote 4D Quote  Post ReplyReply Direct Link To This Post Posted: 17 February 2011 at 10:47am
Originally posted by Bob@DAE Bob@DAE wrote:

Hi,
I just bought a Turbosound Flashlight system with 5 amps (2 EPC760 & 3 EPC780)

I've been looking for the amplifiers manual on the web for several days.
Unfortunately, the link you posted above is out... Can you post an other link to download it ?

thanks !!!!!

Thumbs Up



removed for copyright infringement.. rather sad but true, pm me an email address and I will mail a copy.
DMZ. "The bass was intense. Girls were literally running up to stand next to the subs"
Back to Top
Bob@DAE View Drop Down
Registered User
Registered User


Joined: 18 September 2006
Location: Paris, France
Status: Offline
Points: 10
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bob@DAE Quote  Post ReplyReply Direct Link To This Post Posted: 15 February 2011 at 2:23am
Hi,
I just bought a Turbosound Flashlight system with 5 amps (2 EPC760 & 3 EPC780)

I've been looking for the amplifiers manual on the web for several days.
Unfortunately, the link you posted above is out... Can you post an other link to download it ?

thanks !!!!!

Thumbs Up

Back to Top
4D View Drop Down
Old Croc
Old Croc


Joined: 13 November 2008
Location: Winchester
Status: Offline
Points: 4255
Post Options Post Options   Thanks (0) Thanks(0)   Quote 4D Quote  Post ReplyReply Direct Link To This Post Posted: 22 August 2010 at 1:54pm
ha

Edited by 4D - 11 October 2012 at 1:21am
DMZ. "The bass was intense. Girls were literally running up to stand next to the subs"
Back to Top
Dr T View Drop Down
New Member
New Member
Avatar

Joined: 20 September 2009
Location: UK
Status: Offline
Points: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dr T Quote  Post ReplyReply Direct Link To This Post Posted: 21 August 2010 at 11:24am
Also i have a user manual pdf somewhere, when i find it i'll post it.
Back to Top
Dr T View Drop Down
New Member
New Member
Avatar

Joined: 20 September 2009
Location: UK
Status: Offline
Points: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dr T Quote  Post ReplyReply Direct Link To This Post Posted: 21 August 2010 at 11:18am
I would say that getting 3000w bridged is a bad idea, as the power supplies are completely separate entities, and furthermore, the 4ohm/2 ohm switch function  reduces the power supply rails voltage (at 2 ohms) to prevent the whole thing cooking. Using the amps set to 4 ohm and bridged would be a bigger strain on the capacity of the output devices.  I am currently nurseing one of these beasts back to full health!
Back to Top
djyves View Drop Down
Young Croc
Young Croc
Avatar

Joined: 06 April 2009
Location: the Netherlands
Status: Offline
Points: 564
Post Options Post Options   Thanks (0) Thanks(0)   Quote djyves Quote  Post ReplyReply Direct Link To This Post Posted: 20 August 2010 at 3:59pm
does anyone have a manual, of a epc amp? I can't find them on the internet.

Edited by djyves - 20 August 2010 at 3:59pm
"If brute force doesn't work, you're just not using enough!"
Back to Top
djyves View Drop Down
Young Croc
Young Croc
Avatar

Joined: 06 April 2009
Location: the Netherlands
Status: Offline
Points: 564
Post Options Post Options   Thanks (0) Thanks(0)   Quote djyves Quote  Post ReplyReply Direct Link To This Post Posted: 20 August 2010 at 3:57pm
I think the splitter lead was, to set one channel 180 degrees out of phase, so they could be used in bridge.
"If brute force doesn't work, you're just not using enough!"
Back to Top
4D View Drop Down
Old Croc
Old Croc


Joined: 13 November 2008
Location: Winchester
Status: Offline
Points: 4255
Post Options Post Options   Thanks (0) Thanks(0)   Quote 4D Quote  Post ReplyReply Direct Link To This Post Posted: 20 August 2010 at 1:16pm
I have seen them running in bridged mode with a funny splitter lead on the inputs but as far as I know its not recommended....

250uk pounds is a good price for a superb piece of kit..
DMZ. "The bass was intense. Girls were literally running up to stand next to the subs"
Back to Top
 Post Reply Post Reply Page  <1234>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.094 seconds.