Princeton Reverb screen/grid resistors

[POWDOG]

Well, had Orange Drops in the phase shift positions. Pulled all three and replaced with some Circle D ceramic discs. That was it! It's a little weak, even with a 470K resistor in place of the 1 Meg depth control. But when I lift the NFB, WOW! Real deep. Still gonna tweak the phase shift cap values a little to slow it down, but I would say problem solved. Can't thank you enough for your assistance. Thanks Martin.

[martin manning]

Great! Maybe you can reduce the NFB a bit (increase the FB resistor) and find a sweet spot.

[POWDOG]

I thought about putting a pot in series with the NFB resistor to make a Presence control, still might. But I'm kinda digging the switch. Goes from warm Blackface to kick-in-the-pants Tweed hair with the flick of your finger. I was worried that the Reverb and Trem would bug out when dialing down the VVR, but they both hang in there nicely.

[tubeswell]

Re: the weaker trem - do you notice that it takes a fair bit of pot rotation for the depth control to kick in?

[POWDOG]

The trem actually becomes noticeable quite early in the knob rotation. Definitely more pronounced with the NFB lifted. Put the amp in a cab and hooked up a Weber 12A150A, sounds pretty amazing. A different feel than a PR with fixed bias, but not over-the-top distortion like I expected. Actually about the same amount of headroom. I really like this amp!