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View Full Version : SF Princeton problem

Bluesbuff
02-03-2009, 01:02 PM
I just aquired a silverface Princeton from an estate. It;s condition was unknown other than the light comes on so I get a good deal on it. So last night I plugged it in and tried it out. The output level is really low, clearly audible though and sounds nice and clean. I have some new tubes I'll try out tonight but are there any other suggestions as to what the problem might be?
slider313
02-03-2009, 01:22 PM
It's most likely in need of service; a cap job and making sure all resistors are in spec. The first thing I do when buying any amp is check to be sure the correct fuse value is being used. Princeton and Deluxes without reverb start sounding good around 4-5 on the volume knob.
Bluesbuff
02-03-2009, 09:23 PM
OK replaced all the tubes, worked great so I put the originals back in 1 at a time. The first: V1 12aX7 still worked fine; second: power tubes still worked fine; third rectifier 5U4 still worked fine: last V2 (closest to the power tubes) voila there's the source of the loss of power. This is the phase inverter right? So maybe it was only sending signal to 1 of the power tubes. Just some interesting info for those who may find a similar problem. Serial # and transformer codes date it to 1970. Sticker is missing off the speaker and I haven't pulled it yet so uncertain if it's original but a nice find for $350 I think. Next off to my amp tech for general service.
Born2Blues67
02-04-2009, 02:12 PM
OK replaced all the tubes, worked great so I put the originals back in 1 at a time. The first: V1 12aX7 still worked fine; second: power tubes still worked fine; third rectifier 5U4 still worked fine: last V2 (closest to the power tubes) voila there's the source of the loss of power. This is the phase inverter right? So maybe it was only sending signal to 1 of the power tubes. Just some interesting info for those who may find a similar problem. Serial # and transformer codes date it to 1970. Sticker is missing off the speaker and I haven't pulled it yet so uncertain if it's original but a nice find for $350 I think. Next off to my amp tech for general service.

$350 for a SF PR? That's what i paid for my last one. That was a quite a
few years back. Excellent find. Good luck with the amp.