Bridgeclone - Rowland Concentraclone - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

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 18th June 2003, 06:41 AM   #21
diyAudio Member
Join Date: Oct 2001
Location: .
jrdg usually use its metal case as gound
  Reply With Quote
Old 6th July 2003, 11:37 AM   #22
Luke is offline Luke  New Zealand
diyAudio Member
Join Date: Sep 2001
Send a message via AIM to Luke
anyone got any ideas what the schematic looks like?
  Reply With Quote
Old 6th August 2003, 11:32 PM   #23
diyAudio Member
Join Date: May 2002
Location: Los Angeles, CA
Send a message via ICQ to acliao Send a message via AIM to acliao
Any "back-engineered" schematic available for the Rowland Concentra or Model 10/12 ? thanks.
  Reply With Quote
Old 7th August 2003, 10:12 AM   #24
diyAudio Member
Holger Barske's Avatar
Join Date: Jan 2001
Location: Ruhrgebiet
Concerning Linn2250, perhaps this picture might help .
I can't remember if it was TDA7294 or TDA7293V, but definitely 3 of them paralleled.
Attached Images
File Type: jpg linn.jpg (75.3 KB, 4393 views)
Best regards: Holger
  Reply With Quote
Old 9th September 2003, 01:04 AM   #25
diyAudio Member
Join Date: Aug 2003
Location: Alabama, USA
Originally posted by cm961
It looks like a very nice amp, I hope mine turns out like that

As soon as I get a mill machine and start making two sided PCBs, the possibilities will be endless.

Mills are certainly affordable:

PCB Mills are not that expensive, either.
  Reply With Quote
Old 9th September 2003, 06:42 AM   #26
Electrons are yellow and more is better!
diyAudio Member
peranders's Avatar
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
This is what I ment in this thread. Jeff Rowland looks how it can be expected, very shiny solder joints. I wonder though why the have an opamp in a socket?. Very nice with red pcb, very unusual. Comparte the looks with a Gaincard....inside!
/Per-Anders (my first name) or P-A as my friends call me
PA03 LM4780 amplifier group buy, SIGN UP HERE for the group buy 0 boards left. 118 paid.
  Reply With Quote
Old 12th April 2004, 11:05 AM   #27
LBHajdu is offline LBHajdu  United States
diyAudio Member
Join Date: Feb 2002
I too would be interested in building a similar amp. On the Jeff Rolland site I found a review of there Concentra. It was not in English. There was however an abstract schematic of the amp there.
Attached Images
File Type: jpg jeff rowland concentra.jpg (20.7 KB, 1881 views)
  Reply With Quote
Old 15th April 2004, 09:18 AM   #28
diyAudio Member
Join Date: Sep 2003
Location: MA
If anyone is interested those nice 1% non inductive metal output damping resistors informational PDF is available here: Vishay/Dale output resistors The ones shown in Kuei Yang Wang's pictures are sold @ Mouser for $1.03 USD Mouser

  Reply With Quote
Old 10th October 2006, 04:45 AM   #29
Mrpong is offline Mrpong  Thailand
diyAudio Member
Join Date: Aug 2004
Location: Bangkok
I'm wondering. Why doens't it have elec caps (i.e. 1000uf) near each chip? How is power sent to each chip enough?
  Reply With Quote
Old 11th November 2006, 01:26 AM   #30
rjm is offline rjm  Japan
Richard Murdey
diyAudio Member
rjm's Avatar
Join Date: May 2004
Location: Kyoto
Blog Entries: 165
Is six LM3875 / LM3886s per channel better than one? Certainly more power. Less heat stress on the chips, lower output impedance. Would it also have a better S/N? Not sure. Sound better? Dunno.

Looks like fun to try though. I found the following app note from Apex to be useful:

Apex Application Note #20

Looking through it, one needs to pay attention to the slave amps since they run in unity gain and thus less stable than the main amp which can have a gain of 20 or 30 or so. They recommend using noise gain compensation.

That's if you are going to configure it all as a parallel bridge. Using an input transformer as a phase splitter and running all the amps directly from the tansformer output signal removes this issue completely. :-/

Attached Images
File Type: gif apex.gif (17.6 KB, 536 views)
  Reply With Quote


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bridgeclone carlmart Chip Amps 138 1st April 2005 07:53 AM
Bridgeclone question B.VDBOS Chip Amps 9 2nd September 2003 07:56 AM

New To Site? Need Help?

All times are GMT. The time now is 04:46 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2