Tube Amp Tremolo Thumping

[RGP]

PRR. The Wurlitzer 44 used 2 triple pole switches to select speed, depth and on'off.  What I'm doing is making a clone of the vibrato circuit using a solid state LFO. the switch to ground does work but it takes a few seconds for the LFO to oscillate, which is acceptable. Would it be best to start another thread for that project? I'm not sure how to do that.       

[RGP]

PRR. You mentioned a trick Fender used to start the LFO. How did they do it? 

[merlinb]

PRR. You mentioned a trick Fender used to start the LFO. How did they do it?

One of the shunt resistors was connected to cathode, so it gets a small DC kick when the switch is opened.

[PRR]

There were several variations. As Merlin shows, own-cathode gives small kick. On some large amp (don't ask me which!) the output stage bias supply was used for a big kick. If scaled right, the LFO starts in one cycle with minimal glitch.

[RGP]

Is there a way to do this with the op amp LFO I posted?

[RGP]

Merlin. Thanks for the info. I really love your UBoat. I built one a while back and it works great!