Mini Gold 12AU7 & 12AX7, what to do with them?

[symbolique]

Got these mini JJ12AU7 & JJ12AX7 that was planning for a mini guitar head project.

Anyone know of any good builders or old models that can make some use out of these unused tubes?

[symbolique]

No 1w ro 5w builders?

Was a Frequency Central UK project before he went euro rack...

[crochambeau]

I'd save 'em for rolling in amps or what-have-you, or consider a preamp build, the 12A#7 dual triodes are very common and highly supported.

They are, by themselves, not really well suited to make power.

[waltdogg]

Hang onto them for an emergency. You never know when you or someone you know will need 'em but cant wait for an order from an online retailer. Those gold pin JJs are very common and fairly cheap. Nothing worth building an amp around but a nice upgrade for an amp that comes with regular JJs or Sovteks in the preamp. And yeah 9 pin 12A#7 tubes don't have much output and don't put one in an EL84's socket either. Great way to kill your amp.

[lordgalvar]

http://www.cgs.synth.net/tube/noise.html

[Uncle Grandfather]

http://www.cgs.synth.net/tube/noise.html

magnets

[crochambeau]

You need the Thyratron tube as the noise source though, the AX is just doing standard preamp service in that scheme.

[lordgalvar]

I know. But it's something to do

Just thought it was neat.

[crochambeau]

I know. But it's something to do

Just thought it was neat.

Yeah, it is neat. I've been meaning to building those Eric Barbour circuits for years, even have a perfect enclosure collecting dust in the garage... one of these days.

[culturejam]

And yeah 9 pin 12A#7 tubes don't do output

You can do push-pull output with a 12AU7. Check out the Firefly circuit by Doug Hammond:

[waltdogg]

Oh nice.

[symbolique]

This is similar to what was going to use the Minis for.