2. home-theater
  3. 161953-9815

Madrigal Proceed PAV Schematics

I have a Proceed PAV (the one with button volume control instead of knob) that I inherited from my uncle. I was using it just for 2 channel listening. It started shutting itself off intermittently when I adjusted the volume level. Now, when I power it on, all of the lights go on for a second, and then blank and then I hear a regular clicking sound. I assume that's a relay. Any advice on this issue would be appreciated.
But I am also looking to obtain the schematics or service manual for this component. Madrigal Labs is out of business, and I can't find any contact info for Madrigal/Mark Levinson on the Harman International website.
ubersujith

Showing 4 responses by auxinput

auxinput
2,920 posts
 
Yeah, he is probably right.  It is most likely the capacitors that need to be replaced, but it could very well be something else.
auxinput
2,920 posts
 
Wow, this PAV is from 1995!!   When stuff gets this old, it's very typical for the electrolytic caps to have dried up and will not contain capacitance charge.  This, in turn, will not hold that relay on.  You want somebody to replace those caps.  The following link has a large number of PAC pictures:

http://amp8.com/tr-amp/foreign/proceed/jpeg/

The "pav-b.jpg" picture shows the power supply board specifically.  I can't see anything that might be a relay, but you would probably want to re-cap the entire board.  If you're getting this work done, it's probably worth it to recap the entire unit.
auxinput
2,920 posts
 
Are you planning on doing the re-cap yourself?  Or having somebody do it?
auxinput
2,920 posts
 
You may not have any control over what choice of capacitors they use in the PAV.  I know some of these older equipment used specific brands/models of capacitors to get a certain sonic signature.  If they are just a hi-fi / music repair shop, they may use the cheapest capacitors available for a generic "fixit" solution.  It may change the voice of the PAV.

For what it's worth, I have found the Nichicon KZ caps to be the absolute best for a smaller size cap (1000uf or under).  These are absolutely excellent, but they are larger in physical size and will often not fit into a specific location.  It's often worth it to try to shoe-horn in these caps even if they are sticking out with 1/2" of lead.

For places where the KZ caps can't fit, the Nichicon KW caps are the next best thing.  You will probably have to use KW for the big main power supply caps anyways.

If your repair guy can identify the "standby power supply section", then I would advise using something like the Nichicon PW caps, or something that has a long life (such as 5000 hours at 105 degree).  These definitely don't need the KW/KZ audio caps.
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