Classe DR-9 Big Bang Theory - 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 15th May 2014, 01:15 AM   #1
diyAudio Member
 
Join Date: Feb 2005
Location: Brooklyn, NY
Default Classe DR-9 Big Bang Theory

Hello everybody

When they say "No good deed goes unpunished", they really mean it! My friend in Europe asked me to buy him a Classe DR-9 amp. I found one, in decent shape. Then he asked me if I could convert it to 220 volts. I asked Classe and they sent me a diagram, which, actually, comes as standard in the service manual, which I downloaded. It seemed as simple as one-two-three, so I told my friend I'll do it. It boils down to reconfiguring windings on the block-post. I did it according to the diagram, asked my super to give me a 220 on my fuse box, and plugged it in. There was a huge "bang" as the fuse went, and it began to smell pretty funny. I reconfigured it back to 120, put it on variac (should have done it in the beginning, but it looked so simple, and my variac is only 120), stated to raise the voltage, and around 60v saw the burned parts. They are all on the filter circuit-board all the way down at the bottom, and you need to disassemble the whole thing to get to them (very smart). On top of that, all the bolts are so frozen, that I can't even undo them. Eventually, I think I will get to the board.

I called Classe and asked them if they have a schematic for that board, answer is - no.

So my questions are:

1) what caused the damn thing to blow-up in the first place, if I followed their diagram?
2) were the 220 that my super wired for me responsible in some way? Is the amp very sensitive to where exactly hot and neutral do?
3) does anybody have a schematic for the filter/protection boards? Protection board has 3 red LEDs on it, and I don't know what they are for, service manual says nothing.
4) can anybody fix the amp for me?

Thanks in advance

Mark
  Reply With Quote
Old 15th May 2014, 04:23 PM   #2
DRC is offline DRC  United Kingdom
diyAudio Member
 
DRC's Avatar
 
Join Date: Jan 2003
Location: UK (south west)
Its possible, when wiring two 110 volt windings in series, to get the 'phase' wrong. If this happens then the magnet field cancels and the primary impedance is very low - this will pull a huge current from the mains until something opens the circuit, hopefully a fuse. Reversing the connections on ONE of the windings will correct the situation.

dc
  Reply With Quote
Old 15th May 2014, 10:52 PM   #3
diyAudio Member
 
Join Date: Feb 2005
Location: Brooklyn, NY
Thank you DRC

So, since it's possible, I don't feel like a total moron :-))

M
  Reply With Quote
Old 16th May 2014, 02:16 AM   #4
diyAudio Member
 
Join Date: Feb 2005
Location: Brooklyn, NY
Hello DRC

I just found a very fine print in the service manual. In addition to rewiring the windings, you are supposed to "replace the varistor with correct value". Which value, they don't say. I found a DR-15 manual, which says that the varistor should be replaced from 221 to 441, it does not say however, where this mysterious varistor is located.

???

I think that this is exactly what burned.
  Reply With Quote
Old 16th May 2014, 03:07 AM   #5
diyAudio Member
 
Join Date: Mar 2002
Location: Canada
Look like smarties ; no joke !
__________________
Praudio
  Reply With Quote
Old 16th May 2014, 03:09 AM   #6
diyAudio Member
 
Join Date: May 2010
Location: Skokie Il
Did you test it with 120 volts?

It's too late now.
  Reply With Quote
Old 16th May 2014, 03:36 AM   #7
diyAudio Member
 
Join Date: Feb 2005
Location: Brooklyn, NY
Found the burned varistor. So things may not be as bad as I think.
  Reply With Quote
Old 16th May 2014, 04:05 AM   #8
diyAudio Member
 
Join Date: May 2010
Location: Skokie Il
Quote:
Originally Posted by marknoir View Post
Found the burned varistor. So things may not be as bad as I think.
That would be a nice, simple fix.

Good luck and let us know what happens.
  Reply With Quote
Old 16th May 2014, 04:29 PM   #9
DRC is offline DRC  United Kingdom
diyAudio Member
 
DRC's Avatar
 
Join Date: Jan 2003
Location: UK (south west)
A varistor for 110V would do it :-) .

OK to test with it snipped out, IMHO.
dc
  Reply With Quote
Old 2nd June 2014, 03:55 PM   #10
diyAudio Member
 
Join Date: Feb 2005
Location: Brooklyn, NY
Default Varistor

I'm a bit confused: when shopping for a new varistor, I saw that Classe recommends 221 for 120v and 441 for 220V. I looked at specs, and 221 is a 220v varistor, and a 120v varistor is actually 121 series. Any ideas?

Thx!
  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
Classe DR-8 Modded... willie-aspen Solid State 3 15th July 2013 12:42 PM
Classe DR-3B JohnnyT5 Solid State 3 3rd December 2010 03:01 PM
Where to send my Classe' DR-2 5u4 Solid State 1 12th July 2009 11:58 PM
Classe DR-9 lpd Swap Meet 3 19th May 2004 03:08 PM


New To Site? Need Help?

All times are GMT. The time now is 08:03 AM.


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