70's Princeton - tremelo & tube questions

[SixStrRzr]

I have a Princeton "No-Verb". I have two questions:

1. The "vibrato" at minimum speed setting sounds fast. Is one (or half) of the 12AX7 tubes related to the trem circuit, and may have worn down to cause this? Or is the slowest setting on these amps actually fast,and typical of this amp? As you crank the speed,it definitely goes faster,so I don't think it's the pot. The intensity pot works fine.

2. RE Power tubes: I sent back the new 6V6's that I recently got as one is pulling 24 ma and the other 54. I found 2 older 6V6's in my tube collection that are different brands,but are both pulling 30 ma. Is this too hot for this amp,or am I ok,as long as they are both pulling equal current?

Much appreciated...

[Bruce / Mission Amps]

Originally Posted by SixStrRzr

I have a Princeton "No-Verb". I have two questions:

1. The "vibrato" at minimum speed setting sounds fast. Is one (or half) of the 12AX7 tubes related to the trem circuit, and may have worn down to cause this? Or is the slowest setting on these amps actually fast,and typical of this amp? As you crank the speed,it definitely goes faster,so I don't think it's the pot. The intensity pot works fine.

2. RE Power tubes: I sent back the new 6V6's that I recently got as one is pulling 24 ma and the other 54. I found 2 older 6V6's in my tube collection that are different brands,but are both pulling 30 ma. Is this too hot for this amp,or am I ok,as long as they are both pulling equal current?

Much appreciated...

To slow it down a little, there are three caps in the oscillator, two .01uF ceramic caps and one .022uF cap.
Replace one of the .01uF caps in the vibrato tube circuit with a .022uF cap.
With respect to the power tubes idling at 30ma... well, this is not so much the issue as what is the plate voltage vs idle current.
If you are using an old worn down 5U4GB, the plate voltage might be low enough that 30ma is OK... personally... setting them to 22ma to 24ma sounds better in these amps.