Carvin VTR2800 combo

[Prairie Dawg]

Hi folks.

I am working on a Carvin VTR2800 combo amp circa 1976, a guy I know picked it up in a trade. It's really clean, still has the original fat bottle Sylvania 6CA7s and in all respects is a presentable amp.

The reason it came my way is that it has no bass tone on either channel. That's right. It doesn't matter where you place the eq sliders or which channel or both, you aren't going to get any low end thump at all.

I measured the bias on one tube and it was about 13 ma, so that may have something to do with it. I'm planning on getting it back to Carvin specifications or thereabouts.

It's also been suggested to me that the 4016 IC is suspect. It sits between the two channels and I'm told it is prone to failure. You couldn't prove it by me, but that's what I've been told and it's slated to get a new IC and a socket to mount it into.

Looking at the block diagram that's in the owner's manual, there is also a 4136 that is common to both channels, so I'll be looking at that too.

the rest of the ICs other than the 4016 are "war of the worlds" tripods.

Is there anything else that I should be looking at?

Thanks all.