Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

An oldie. Maybe a goodie?
An oldie. Maybe a goodie?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 26th January 2009, 10:54 AM   #41
east electronics is offline east electronics  Greece
diyAudio Member
east electronics's Avatar
Join Date: Jan 2006
Location: Athens GREECE
Default triple woaw !!!!!!!

Perreaux factory tour

thats they way i like to make amps .... no mater if cost effective or not .....
  Reply With Quote
Old 26th January 2009, 01:31 PM   #42
SpeakerScott is offline SpeakerScott  United States
diyAudio Member
Join Date: Jul 2008
Send a message via AIM to SpeakerScott Send a message via MSN to SpeakerScott Send a message via Yahoo to SpeakerScott
Default Re: thanks OS

Originally posted by sakis
but your answers dont look really enough ......

what i mean is ....How come an amp like that runing at so much high rails doesnt requier CCS and out resistors ????


Matched transistors and lateral mosfets which have a negative temperature coefficient. Personally, at those power levels, with that number of transistors even with matched lateral devices....I wouldn't do it. But I'm an overly cautious sort. I would strongly recommend against running without degeneration resistors with hexfets or bipolar transistors.

As far as CCS...proper dominant pole compensation and most likely higher distortion...and it'll be fine.

I bought a BGW amp at a pawn shop and proceded to spend over a year fixing someone elses "fixes" on a previously blown channel. When something as a time constant of an hour or two there are only sooo many tests you can run in one night. The BGW used Motorola bipolar output devices, 10 per channel with .22 ohm emitter degeneration resistors. I eventually traced it down to the previous repair tech did not adequately tighten 2 of the transistors to the sink.

https://www.facebook.com/DIYRM/ See FaceBook page for >100 pages of design guides and articles.....
  Reply With Quote
Old 26th January 2009, 03:20 PM   #43
Steve Dunlap is offline Steve Dunlap  United States
diyAudio Member
Steve Dunlap's Avatar
Join Date: Sep 2008
Location: Here
Originally posted by jacco vermeulen
The static killed them ?
The 80s fashion of restamping or making output devices incognito was pretty amusing, as if there was a vast array of different devices to pick from.

The static killed them. They were using a wire wheel on a grinder.
  Reply With Quote
Old 15th February 2009, 08:02 PM   #44
ungie is offline ungie  Canada
diyAudio Member
Join Date: Dec 2002
Location: Ontario, Canada
Things have been very hectic at work over the past couple of weeks, so I have not had a chance to continue working on the PMF5550. I will likely start with replacing all of the front end electros and see if that improves the DC offset.
I also had a very nice reply to an e-mail I sent to Perreaux service.
In his response he said that the correct output bias is 50ma per device. This applies to all Perreaux amplifiers.
Also, interesting enough, their current service people do not really know what effect RV2 has on audible performance and indeed it has nothing to do with DC offset.
Apparently it's an adjustment to improve measured performance in some way, but I am told that they usually set it so that +6.2V appears at the wiper.
  Reply With Quote


An oldie. Maybe a goodie?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

New To Site? Need Help?

All times are GMT. The time now is 04:43 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio