Help identifying Bottlehead preamp & rectifier

[iLikeSound]

Hello all,

New here. At some point I'll buy and build a kit. In the meantime:

I recently bought (via craigslist) a Bottlehead preamp. Hoping you could help tell me which one it is (or if it's a FrankenHead). The small tubes are both 12au7.

I also can't identify the rectifier. The base says RCA Electron Tube, and has Made in USA, and 3-39. The internal parts look interesting to me: The upper and lower spacers are toothed, like a bike cog, and the plate is cylindrical. It glows blue.

Pictures below. Thanks in advance!

[Natural Sound]

Thats a Foreplay III. The "regulator" is an 0D3, 150V regulator. The rectifiers are solid state. Does it work OK?

[iLikeSound]

Thanks a lot - that was fast!

Yes, it works fine. Sometimes I need to wiggle the input cables a little to get one channel to work, but I'll clear that up as soon as I open it and check the solder connections.

Will changing the regulator (to a different brand, or a different type) affect the sound much (or at all)?

[Natural Sound]

I never found regulator tube rolling to have an effect on the sound.

[Doc B.]

It looks like it uses the basic Foreplay III circuit and probably one of our power transformers. But it's not a Foreplay III factory chassis. So yes, it is in some ways a Frankenstein.