Rega Brio (one channel dead) - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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
Reply
 
Thread Tools Search this Thread
Old 30th March 2005, 12:06 AM   #1
cosinus is offline cosinus  France
diyAudio Member
 
Join Date: Mar 2005
Location: paris
Default Rega Brio (one channel dead)

Hi everybody !
I'm new here and I need a hand.
I have an old rega brio integrated amp with one dead channel on the power amp. I don't know what happened to it, I just got it like that.
So I opened it. Besides the fuse, there are a few resistors that are badly burnt. The schematics show which ones.
My question is: how should I proceed to fix it ? I mean which method should I follow.
-Should I change everything in the faulty channel, including all transistors and just set idle current at the end ?
-Are there any other components that are most likely dead too ?
-Should I only change the burnt resistors ?
I have an oscilloscope, a digital multimeter. And I'll use my PC as a signal generator to feed the preamp.
And I'm willing to spend some time on it because I find it interesting. Otherwise I'd have it serviced but it's a lazy option.
I would really appreciate the help of one of you guys. I am far from having your skills, but I studied electronics at school and can use all the instruments I listed. If I need something more, please tell me.
Thanks in advance.
Attached Images
File Type: jpg brio.jpg (40.0 KB, 1756 views)
  Reply With Quote
Old 30th March 2005, 03:19 PM   #2
cosinus is offline cosinus  France
diyAudio Member
 
Join Date: Mar 2005
Location: paris
Default Found something

Hi there !
I realise it was a complex question, so I went searching a lot more. Well, I found this:
http://sound.westhost.com/troubleshooting.htm
It looks really good, just what I wanted. You might know it already. I post it in case some of you don't.

But there are still a few questions for you guys:
-What's your opinion about this amplifier, looking at the diagram ?
-What are your ideas to improve it ?

Regards
  Reply With Quote
Old 11th July 2005, 09:58 AM   #3
diyAudio Member
 
Join Date: Jan 2002
Location: Europe
What a coincidence! I have the same amp with one channel dead. When I opened it, one fuse was blown. And two resistors.

But I don't see the resistor number listed on your schematic. Is that the complete schematic?

Maybe you have another part of the schematic.

Your help is highly appreciated.

Frank
  Reply With Quote
Old 11th July 2005, 10:24 AM   #4
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
It is likely that T1, T2, T5 and T6 will be blown. You should replace these. Also check the op-amp is working. You may as well replace all the transistors as there's so few of them. You might be better dropping a better op amp such as NE5532 in there instead of the TL072 too, but if all you want is to get it working, replace with a TL072.
  Reply With Quote
Old 11th July 2005, 11:09 AM   #5
Banned
 
Join Date: Jan 2005
This is a DC coupled amp, most likely the output transistors went which fried the fuse and the paralell resistor, this means you need to changre about everything on this channel board, including the opamp. Look for burnt copper traces too.
  Reply With Quote
Old 11th July 2005, 12:59 PM   #6
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
It's not exactly a very well designed amplifier. The driver transistors are only rated for 100mA, and well, the 2955/3055 is older than time. Theres also no resistance to isolate the 2955/3055's from the speaker line. Looks like a recipe for disaster when it goes wrong.

Don't bother getting it serviced if you can do it yourself. Luckily the low parts count means it's relatively cheap to replace all the parts in the channel. You can get all of the transistors from OnSemi as samples
  Reply With Quote
Old 11th July 2005, 01:08 PM   #7
diyAudio Member
 
Join Date: Jan 2002
Location: Europe
Thanks a lot for your replies. Does any of you have the complete schematic with a parts list?

Best regards,

Franco
  Reply With Quote
Old 20th July 2005, 11:11 AM   #8
Ipanema is offline Ipanema  Malaysia
diyAudio Member
 
Ipanema's Avatar
 
Join Date: Jun 2004
Location: KL
Default Layout

Hi,

Out of curiosity of how this simple circuit may sound I build it with the layout attached. Currently one channel is working and another is coming. The working channel sounds find but it have a fairly loud "waterfall" noise, not "motorboating" sound, which is noticeable when no music is playing. Pls help to check what is wrong with my layout that causes this.

FYI, I use wire jumper to connect the "unrouted" path, which is VEE, VEE and regulator (7815/7915) to opamp.

Pls advise.

Thanks.
  Reply With Quote
Old 20th July 2005, 11:13 AM   #9
Ipanema is offline Ipanema  Malaysia
diyAudio Member
 
Ipanema's Avatar
 
Join Date: Jun 2004
Location: KL
Default Layout attachment

Here's the layout. Sorry
Attached Images
File Type: jpg rega brio nocomp.jpg (46.0 KB, 1128 views)
  Reply With Quote
Old 20th July 2005, 11:15 AM   #10
Ipanema is offline Ipanema  Malaysia
diyAudio Member
 
Ipanema's Avatar
 
Join Date: Jun 2004
Location: KL
Default with components

With components
Attached Images
File Type: jpg rega brio with comp.jpg (88.9 KB, 1075 views)
  Reply With Quote

Reply


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
Help. dead channel on GFA 555. chucker Solid State 4 17th May 2008 08:45 AM
Dead channel Carlp Tubes / Valves 15 1st February 2007 04:54 AM
2020 T-Amp Kit: One Dead Channel mourip Class D 5 14th February 2006 02:09 AM
HELP with a rega brio! jercab Solid State 1 5th October 2005 02:43 AM
Peavey 8.5C DeAd cHaNnEl Pbassred Solid State 3 10th May 2005 12:44 AM


New To Site? Need Help?

All times are GMT. The time now is 04:34 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2