Ampeg B-12XY Scratchy intensity pot (Sluckey) HELP

[punkykatt]

http://el34world.com/charts/Schematics/files/ampeg/Ampeg_B12XY.pdf

I  did a clean up/routine maintenance, replaced all E caps and out of spec R`s.   Everything on the amp works  and sounds beautiful.  I noticed that when the vibrato is activated and I turn the intensity pot I get a scratchy sound at the beginning and then at the end of the pot rotation. When the vibrato in not activated there is no scratchy sound.  What I have done so far:  Triple clean pot, replace pot, replace cc C-18, 19 & 24.  Scratchy sound still there????  Is that normal for this amp?  Thanks in advance Punky

[sluckey]

Does the scratchy sound persist even when you quit turning the knob?

[punkykatt]

No.

[sluckey]

You've already changed all the obvious stuff. I'd just let it ride, ride, ride.

[punkykatt]

Let it ride ride ride.  Thanks Sluckey.  I guess it just is what it is what it is what it is.  I tried.  The customer will have to live live live with it. 

[PRR]

> replace cc C-18, 19 & 24

Replace C8 C10 C11 C12.

Try adding 0.02uFd from pot wiper to ground.

[punkykatt]

PRR, thank you for the suggestions. I tried them, scratch is still there.

[PRR]

Sorry!

I was trying to find ANYthing which could be leaking DC onto the pot wiper. As you had cleaned and changed(?) the pot, DC leak seemed likely. Wish it had helped.

[punkykatt]

Thats ok.  I even tried several pots too, thinking I had defective new.  One of those rare mysteries.  Thanks again.