The Amp Garage

New jacks? Make VERY sure that you've wired them correctly. Bad ground reference on the input grid will hum a lot. I stared at the inputs on a '54 Twin for days before realizing what I had screwed up.

The other thing about solid core is that it's better at transmitting mechanical vibrations.
Since capacitors are all microphonic to some degree, this can do good things or bad things.
I think Ken Fischer knew how to make this work for him.
Just a thought.

Marshall used both 82K and 150K over the years. Try it yourself. You won't hear much difference. The tubes will be happier with lower resistance. KT88s seem less fussy about this, but that is only my experience.

I'd lose the GZ34 and use the space to spread the 6550s farther apart. Pretty hot tubes. If you get them far enough apart, you might be able to use KT88s, too. For the 6550s especially, you should reduce the grid return resistors from 220K. I don't think you have go all the way down to the 50K the t...

I saw the 10W resistor and assumed.

70W "ultralinear"?

+1 on Stephen's 5V4 suggestion. Get a NOS one, tho.

A DR has a 220K to ground from the junction of the 3M3/470K. The Princeton Reverb omits it to compensate for lack of gain in the PI. If you put it in, the amp should clean up a bit.

tedsorvino wrote: ↑Thu Sep 21, 2017 8:55 pm Lug 3 goes to a 1A/1200v diode (+ side) and a 47uf/100v , the diode (- side) goes to a 1k ohm/5w resistor

As described, the diode is backwards. Check.

Don't forget to add a coupling cap off the V1B plate. Your schematic doesn't show it.

15 volts on pin 8 through 1 ohm?

You might want use snail mail for this. Write to their Legal Department in San Jose and maybe look up their registered agent for service in New Mexico. The have agents in all 50 states to receive lawsuit paperwork and other state-level notices. They used to use National Registered Agents Inc. and ma...

Did you measure it?

The tick comes from the neon bulb in the roach flashing. Sometimes a new bulb helps, but the principle causes of the tick leaking into the signal are conductive board or lead dress; the trem leads should be dressed well away from the tone stack leads. You might even try shielding them.

Bias mod trems on output tubes can be fussy about how the tubes are biased in the first place. If the bias is set hot, the trem will typically have less effect. Since it was working and then didn't, I'd guess the 6V6s have settled in and are drawing too much current. Try adjusting the bias circuit t...

This is the problem I've always had with Mr. Keen: I know that he knows what he is talking about, but I have no idea what he's talking about. Love you RG.