What to do with these tubes?

peccary

Well-known member
So I feel kind of silly, but Electronic Goldmine was having on a sale on some silver mica and, feeling that I needed to buy more to justify the shipping and initial purchase, I did what any decent hoarder collector would do and bought some random stuff I don't need or have any current plans for.

They were selling grab bags of old tubes and I figured what the heck.

Well, now I need to find something to do with them but have no idea whether or not these will be useful in anything I might do in the future.

If anyone has any advice or knows a project that could use something here I am all ears (eyes?). Also, if someone sees something here they need let me know.
 

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vigilante398

Authorized Vendor
@peccary You've got some weird ones in there my dude. The only one you're likely to find anything ready to go for is 12AT7, that can of course be used anywhere you would use a 12AX7 but with a little less gain.

There are some interesting things in there that would make fun one-off projects if you're looking to experiment though:
  • 8AR11 is an RF tube, not much use for audio there.
  • 12AE10 is a dual pentode, but one is a sharp-cutoff pentode and the other is a beam power pentode, so you could do a pentode preamp into a pentode power amp, all with a single tube! Pretty neat.
  • 10DE7 is a dual triode, but the pinout is different than 12AX7 so it's not a drop-in replacement. Also is takes a 10V heater instead of 12.6V. Looks like the plates are pretty beefy though, you could possibly use it as a triode power section for a low-wattage amp.
  • 4AU6 is a sharp-cutoff pentode, you could use rig up a single pentode preamp, but it's not pin-compatible with anything common so it would have to be a one-off design.
  • 12AF3 is a flyback diode, not much use to the modern audio world there either.
  • 6KZ8 is neat, it's half triode and half pentode, so you could cascade the two of them for some neat tones or you could do a dual channel preamp where you can choose triode input or pentode input.
  • 25C5 is a neat little beam power tube, you could use it as a power stage in a low-wattage amp build.
  • 2AF4 is a triode designed for use as an oscillator. The datasheet says UHF, which means it would be too fast for anything like a tremolo, so probably not much use there.
So there are a good handful that something interesting could be done with, but you're unlikely to find anything already out there except for the 12AT7.
 

peccary

Well-known member
@peccary You've got some weird ones in there my dude. The only one you're likely to find anything ready to go for is 12AT7, that can of course be used anywhere you would use a 12AX7 but with a little less gain.

There are some interesting things in there that would make fun one-off projects if you're looking to experiment though:
  • 8AR11 is an RF tube, not much use for audio there.
  • 12AE10 is a dual pentode, but one is a sharp-cutoff pentode and the other is a beam power pentode, so you could do a pentode preamp into a pentode power amp, all with a single tube! Pretty neat.
  • 10DE7 is a dual triode, but the pinout is different than 12AX7 so it's not a drop-in replacement. Also is takes a 10V heater instead of 12.6V. Looks like the plates are pretty beefy though, you could possibly use it as a triode power section for a low-wattage amp.
  • 4AU6 is a sharp-cutoff pentode, you could use rig up a single pentode preamp, but it's not pin-compatible with anything common so it would have to be a one-off design.
  • 12AF3 is a flyback diode, not much use to the modern audio world there either.
  • 6KZ8 is neat, it's half triode and half pentode, so you could cascade the two of them for some neat tones or you could do a dual channel preamp where you can choose triode input or pentode input.
  • 25C5 is a neat little beam power tube, you could use it as a power stage in a low-wattage amp build.
  • 2AF4 is a triode designed for use as an oscillator. The datasheet says UHF, which means it would be too fast for anything like a tremolo, so probably not much use there.
So there are a good handful that something interesting could be done with, but you're unlikely to find anything already out there except for the 12AT7.
Wow!

Thank you for all of this information. I was going to look them up tonight after work but you saved me an hour or two at least, and that's just discovering what they are, let alone what they may be useful for.

Thank you for the starting points, I really appreciate it. If you want anything here to experiment with let me know and it's yours.
 

fig

Village Idiot
They were selling grab bags of old tubes and I figured what the heck.
Yours came in boxes? Mine arrived loose in one box. You must have bought the premium discount grab bag. :ROFLMAO:

@vigilante398 left out this possibility...

c9qcCax.jpg
 

HamishR

Well-known member
You know the christmas ornament idea is not so silly - I think a lot of these tubes are quite attractive. I've seen people make little figures out of transistors and resistors, so why not with tubes? You could make some '50s sci-fi robots with them. If you were keen you could even work out a way to make them into christmas tree lights. Except you'd probably burn the house down.
 

Chuck D. Bones

Circuit Wizard
So I feel kind of silly, but Electronic Goldmine was having on a sale on some silver mica and, feeling that I needed to buy more to justify the shipping and initial purchase, I did what any decent hoarder collector would do and bought some random stuff I don't need or have any current plans for.

They were selling grab bags of old tubes and I figured what the heck.

Well, now I need to find something to do with them but have no idea whether or not these will be useful in anything I might do in the future.

If anyone has any advice or knows a project that could use something here I am all ears (eyes?). Also, if someone sees something here they need let me know.
Fig & I are in the same boat, only we went hog-wild and bought the 50-tube grab bags.

What I got was mostly TV tubes with odd-ball filament voltages, but there were a few gems in there like 6SN7, OA2, 6U8, 6BQ6 and some metal-case tubes. Lotta compactrons, some of which are dual pentodes that like Vigilante says, could be used to build a 1-tube practice amp.

Gonna take some time & creativity. The odd filament voltages can be accommodated with a series resistor.

I have yet to test any of them.
 
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