ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Behringer Mixer help


 
7/30/2003 11:32 PM
DanJ
email
Behringer Mixer help
Hello,  
 
Does anyone know where I can get a schematic for a Behringer MX3282A mixer. This thing lights up like a Christmas tree. It has a seperate power supply. Any help would be greatly appreciated. Thanks all.
 
7/31/2003 3:54 AM
Enzo
email

Dan, if all the peak lights and everything come on, it is almost certain one of the analog power rails is missing. The power supply provides +/- 15 or 18 or something close. If one of those goes away, then all the op amp outputs slam over to the remaining rail and the peak meters just interpret that as a max signal.  
 
Look at the corners of any op amp in the mixer and see if the volyages are both there. COuld be a connector problem in the umbilicle, or the supply itself has a problem. I think this thing uses three terminal regulators, whatever the next step up from LM317 is.  
 
On the other hand, I have had to chase down a short across one of those rails out in the mixer. Every chip has a small blue bypass cap mext to it, and if it shorts, then the rail will load down to nothing. Usually a small black hole forms on the part, but not always. It can be a real bear to find it. Separating the sections of PC board can help.
 
 
  Wednesday
Book Of The Day The Ultimate Tone, Volume III by Kevin O'Connor
Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

Note: The Ampage Archive is an Amazon Associate site. A small commission is paid to the site owner on any qualified purchase made after clicking an associate link such as the one above.
 
8/3/2003 1:23 PM
DanJ
email

Enzo,  
 
Thanks for the info. I knew when I posted that I was missing the 12VDC supply. Thanks for the explanation of why that would cause it to light up.  
 
The power supply board has a few open runs and lifted pads from a previous "repair". So I'm trying to figure out what all should be connected.  
 
Hopefully its just the open runs and not in the board itself. That does sound like a pain in the butt to find. Thanks again.
 
   Page 1 of 1