Trem-O-Nator Sharing Envelope With Reverb Recovery-OK?

[W5FH]

Hello-
    As it ends up I may be looking at putting the Sluckey Trem-O-Nator on one side and a reverb recovery amp on the other side in a 12AX7 envelope. Does anyone foresee a problem with the oscillator getting into the reverb recovery amp? Thought I would ask in case someone else has had an issue with something like this or similar. Thanks.

[sluckey]

I haven't tried it and ain't gonna. The oscillator produces a HUGE signal. On my Band Master it is 110V_rms. That's 311V_pp. And the reverb recovery deals with the smallest signal in the amp. Seems like an invitation to trouble to me.   

[W5FH]

Thank you Sluckey. I agree with you now that you have enlightened me on the strength of the osc signal! Scrap that plan, for sure.
Thanks, Byron

[PRR]

...The oscillator produces a HUGE signal. On my Band Master... 311V_pp.

A healthy oscillator, without fancy amplitude control, will make very nearly its supply voltage as peak-peak output. It wants to "grow without limit" but it can't exceed, or closely approach, its supply voltage. Seeing 311Vpp suggests a 350V or so supply, maybe 400V if you load it hard. (Yes, I also get a clue by knowing about what a Bandmaster is; but the same relationship applies in 3V systems or 100KW radar modulators.)

OTOH, 10Hz wobbles don't couple like radio waves. I can believe someone has done and lived, even thrived. But it seems a less-good bet.

[astronomicum]

I can believe someone has done and lived...

The Univox models U-320, 1221, 1226, 1000, and 1011 had the LFO and reverb recovery in one 12AX7.

[W5FH]

Very Interesting -
    Thank you for this information showing it being done, I will research it. Maybe just for the knowledge, but nevertheless a learning experience.

[tdvt]

Not to totally hijack the thread.... but what other circuits would be a less iffy use of the unused triode with the Trem-o-nator circuit?

[sluckey]

I don't have any qualms about leaving half of a 12AX7 unused. It's not a sin. But if it bothers you, switch to a 6AV6. Then ponder what to do with the two unused diodes.   

[tubeswell]

I’ve tried a LFO in the same 12AX7 tube as an ordinary gain Stage and got unwanted cross talk (‘thumping’), which was cured by separating the stages into different tubes.


Princeton Reverbs have the LFO on in the same 12AX7 as the cathodyne PI and get away with it (because a properly set up cathodyne has good common mode rejection).