Carver C4000 Preamp Help....!

nadude98

nadude98

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It turns out my Preamp has been the culprit all along when I thought I had messed up the build of my WOPL. Is it possible for me to potentially fix it or do I need to leave it to a pro. The problem in high dc at the output on the left channel. I also tried turning off everything i.e. tone, sonic holography, etc.

Left channel has about 250mvdc on it which will go down to about 150 when I take the tone controls out.. Also it was making the amp sound bad at high volumes, plus I have always thought I had to turn up the volume control too much to get the volume I was actually getting.

I'm going to download the manual and start researching but any input I can get would be appreciated!
 
nadude98

nadude98

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laatsch55 said:
Just happened to have some laying around??
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I had read something about those possibly needing to be replaced and so I had ordered a couple and had them on hand. :happy3:

After my wife went to work I could finally crank it up and the preamp is still acting up, just not as bad as it was.. ! Dang it!!!
 
nadude98

nadude98

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grapplesaw said:
Here are those located for future reference?
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There is a bulletin in the service manual on them. They are located on the main board and you have to pull the 3rd board from the left to gain access. If they have been replaced they will be facing the back of the amp otherwise they will be facing the front.
 
nadude98

nadude98

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I was going through the preamp as I had changed the two jfet's which took care of the high DC on the left channel but the preamp is still not right. Really bass heavy stuff at higher volume sounds washed out or muddy... trying to describe it is hard... lol.

I did a little recapping with caps I had on hand. Well I got to the Peak Unlimiter board and discovered that C7 and C7R are listed on the schematic as being 4.7uf 6.3v and what was on the board was a 2.2uf 63v and a 2.2uf 50v

Can someone verify what is or should actually be in there? I have the C on my serial number.
 
laatsch55

laatsch55

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There were probably so many undocumented changes you should stick with what you find on the board...
 
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