'72 Princeton Reverb problem... help!

[pedrohead]

So I just picked up a Princeton Reverb this evening that had basically been sitting in a closet for 30 years (it's true, it really does happen).

I turned it on and once you get the volume above about 2-3, horrible static/farting bursts start blowing through the speaker. I was thinking (hoping) it was just a tube problem. You could tap on the pre tubes and occasionally that would start light static noise (or stop light static noise) and some it was like hitting a tuning fork and a shrill tone just shot out of the speaker (with the volume all the way off).

I swapped out the preamp tubes en masse with some that I know are working, and the problem was still there (not as much with the microphonic tapping, but loud bursts of static that were only there during playing over 2-3, especially with bassier notes). I plugged the speaker into another amp and the speaker seems ok.

I took some 6V6 tubes out of an old Deluxe that I have (these tubes are likely even older though...) and didn't help. And didn't have another rectifier tube like this amp had.

Does this sound like a power (likely not) but maybe rectifier tube problem?

Anything else I can do to try and diagnose? I don't have a good amp tech too near me and would like to eliminate some easy possibilities before paying a bunch to go get it fixed somewhere. Thanks.

 

[hathisisfunnyha]

take it in to amp tech. it sounds like it needs a thorough cleaning and checkup. also check to make sure the speaker is unharmed.

i just dropped my 65 princeton reverb off to get a full checkup, and hoping that it has minor issues versus major.

the more you play it in a dilapidated state the more damage you can cause

 

[pedrohead]

take it in to amp tech. it sounds like it needs a thorough cleaning and checkup. also check to make sure the speaker is unharmed.

i just dropped my 65 princeton reverb off to get a full checkup, and hoping that it has minor issues versus major.

the more you play it in a dilapidated state the more damage you can cause

Yeah, I hear you. I'm just hoping to get anything obvious or cleaning out of the way first.

Any other ideas?

 

[slider313]

The electrolytic caps in the amp are 37 years old. You are in dire need of a cap job.

 

[pedrohead]

The electrolytic caps in the amp are 37 years old. You are in dire need of a cap job.

Thanks for the input. Do you have any idea what something like that typically runs on an amp this size?

 

[slider313]

Thanks for the input. Do you have any idea what something like that typically runs on an amp this size?

Typically between $150 and $250 for caps and a complete service which would include cleaning tubes sockets,pots,grounds,input jacks,switches,checking for leaking coupling caps,bad tubes,solder joints and making sure all resistors are in spec.

 

[Blue Strat]

Try cleaning all tube pins and sockets. Check the FAQ on my website under RESOURCES. Bad connections, sometimes tube related, are a very common cause of the symptoms you're experiencing.

 

[pedrohead]

Thanks guys. I had actually gone in this morning and cleaned all the pots, input jacks, tube pins and tube sockets, and it seems to have gotten a little less noisy, but still the same loud bursts of static if playing a bass-ier chord or turning it up louder.

You mentioned checking or cleaning "grounds", what are you looking for there?

 

[leftyaxeslinger]

I wouldn't go poking around in there. Take it to a reputable amp tech.

 

[teleking36]

cap job needed. once you get that taken care of, along with a routine service of the amp, you'll be good to go. i haven't stopped playing my '68 PR since i got it a few weeks ago.

 

[pedrohead]

I wouldn't go poking around in there. Take it to a reputable amp tech.

Trying to do so right now... can't get any of them to call me back

 

[hathisisfunnyha]

where do you live? odds are someone on here knows a good tech in the area

 

[pedrohead]

where do you live? odds are someone on here knows a good tech in the area

I'm near Detroit, MI. I ended up getting it in this afternoon, just had to call these guys every 30 minutes until someone answered...