Rick-Tone Trem-O-Drive capacitor voltages

[Yazoo]

Yet another lock-down project, the Rick-Tone Trem-O-Drive. The details are here: http://www.ricktone.com/tremodrive.shtml

I am going to dispense with the voltage doubler as I am using 2 230:12 volts transformers in the UK. On the schematic the capacitors are noted as being 400v unless otherwise marked but I think only the 2 capacitors directly connected to the plates of the 12ax7 need to be this high, the .015uf and .047uf capacitors. I was going to use 50v caps for the cathodes (noted for the 10uf) and 100v caps elsewhere. Have I got this right please?

[antonis]

IMHO, 10nF & 33nF should also be rated at 400V..

[PRR]

At turn-on, before the tubes warm, you can hit 336V or more. That's on the plate caps. But when running, the voltages inside the C-R-C-R-C-R network are astonishingly high. I've heard of too many "for no reason" failures here. Often after much time; there's considerable headroom in most caps but eventually it all burns away.

I'd go 400V on the "*" caps, >2V on the cathode caps. I doubt the grid cap can see high voltage but it is cheap to make it >>50V.

[Yazoo]

Thanks, I went ahead and ordered 400v versions.

The reason I asked was because I thought the caps connected to the plates would block the high DC voltages fron the rest of the circuit. I modelled the circuit in LTSpice and sure enough the voltages were higher than I expected.

[LightSoundGeometry]

Uncle Doug

[Yazoo]

Yes, it was Uncle Doug who introduced the Trem-o-Drive to me. I'm an avid viewer. I really like D-Lab's videos as well.