Princeton Reverb volume issue

[Curbdog]

I just finished a Princeton Reverb build, and the volume is stuck on full-up, all the time, no matter where the amp volume knob is dialed. It looks like it is wired correctly to me. What could be the problem? Thank you.

[tubeswell]

definitely wired incorrectly. Have you got the vol pot ground lug grounded?

[Curbdog]

Yes, as I look at the back of the volume POT, the left lug is grounded.

[Bob-I]

The first thing I would do would be to trace out all the connections. Print out a copy of the layout and one by one, trace the connections, using a highlighter to mark the one's you've verified as correct. I do this with every amp I've built and prevented a bunch of mistakes this way.

If you don't locate the error this way, post detailed high res pics of the build and other eyes will help.

Good luck.

[jhaas]

Yes, as I look at the back of the volume POT, the left lug is grounded.

If you're judging by visual inspection alone, that may not be enough, verify it is connected to ground using your DMM. I had the same situation once. The pot was grounded thru the input jack, which *looked* fine, but one of the solder joints on the (Cliff) jack was bad.

[tubeswell]

Yes, as I look at the back of the volume POT, the left lug is grounded.

Yes but does it read as grounded (to the chassis) with your R-meter?

[Curbdog]

It was a bad volume POT. Replaced it, and all seems fine now. Thanks for all the trouble-shooting tips.

[Curbdog]

New problem - now, when I turn the volume up high, about 2/3 or 3/4, and play I begin to get some harsh crackling and static in the tone. It appears to be worse the harder I pick. I am tempted to just use the shotgun approach again (worked the last time) and replace all the POTS and coupling capacitors. I have some mica caps in there, and I have had them be noisy like this in the past. Anything else I might check out? I have read that the concertina splitter has the potential to cause some nasty distortion. Thanks.