Ivy League – or, am I cut out for Princeton?
The trials of making a Silverface (‘68) Princeton reverb walk the walk.

I acquired this puppy in a local pawn shop early summer of ’06 for a relative pittance. The amp functioned but the reverb was inoperative, so after the requisite hobby-haggle, I believe a walked out the proud daddy of the Princeton for about $65.

Back in the eighties I had owned bigger guns (a Twin w/ JBL’s comes to mind) and I recall at that time we spurned the little Fenders (Princetons, Deluxes, Vibroluxes, etc.) as being “too tiny” for serious work.
Like everything opinion I’ve ever held, time changes it.

I had managed for decades to hold onto my old Blackface Bassman, but it was both too loud (50 watts cooks when you are pushing it to get “the brown”) and too big, requiring a separate cabinet.

A wife, two kids, a mortgage and all the resulting responsibility later, music has become (more realistically) a stress-relieving hobby for me. The band riser seems long, long ago in a galaxy far, far away. So much for the reminiscence.

After getting the Ivy-league home, I disassembled it to see “what be wrong”. The driver tube for the reverb (a 12AT7 on these) had the top cracked off, the pilot-light was burnt out, the reverb tank had some broken leads from the connectors to the spring voice-coils and the speaker baffle was bowing. After some parts runs and some creative gluing and bracing on the baffle, she was up and running.

The little amp sounded (technically) fine, with no squeaks/hums/groans, but also sounded listless, lacking the typical fender snap. The speaker it had come with was aftermarket, nominally 4 ohm (measured 2.8) and way too big. This puppy had a 2” voicecoil and about a 6 lb. magnet. Aside from the fact that it could suck-up 5 times the power the Princeton could kick even on a good day, I speculated that the huge voice coil and heavy cone was killing what highs the amp could build.

I started looking online and liked the response curve some of the Celestions were showing. They had a peak right about 2.8K, upper mid for most young ears, but high-end for mine. I bid in an auction for a “Tube 10” and won it. 1 week later it was installed in the amp, and I was blowing through it enjoying the new fire. It really lit up with the old Tube-screamer set up to overdrive the front-end. Half-way through my nightly mid-life crisis, the thing developed a low freq. hum that sounded like feedback. Off the power switch went.
I lit it up the next night and let it idle with all on 10. About a half-hour later, the hum is back, so I grab a rag to shake some tubes. As soon as I grab one of the (original RCA) 6V6’s, the hum stops. When I let go, it starts again and so on. Apparently, the same drop that broke the reverb driver had done a number on the grids in the power tube.