# What to do with these tubes?



## peccary (May 18, 2022)

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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## andare (May 18, 2022)

First of all this is perfectly normal behavior, @peccary 

I think @vigilante398 might be able to make suggestions.


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## vigilante398 (May 18, 2022)

@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.


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## peccary (May 18, 2022)

vigilante398 said:


> @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:
> 
> ...


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.


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## peccary (May 18, 2022)

Bummer the 12AF3 won't be of any use. It's wearing a pretty stylish little hat.


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## Harry Klippton (May 18, 2022)

Shove em up your butt!!!













Sorry Joe, I want to respond with that _EVERY_ time someone asks a question like this but restrain myself


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## peccary (May 18, 2022)

Harry Klippton said:


> Shove em up your butt!!!
> 
> 
> 
> ...


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## fig (May 18, 2022)

peccary said:


> 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. 

@vigilante398 left out this possibility...


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## Harry Klippton (May 18, 2022)

fig said:


> Yours came in boxes? Mine arrived loose in one box. You must have bought the _premium_ discount grab bag.
> 
> @vigilante398 left out this possibility...


That one looks like you already shoved it up your butt


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## Barry (May 18, 2022)

You could always make them into Christmas ornaments


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## EGRENIER (May 18, 2022)

Harry Klippton said:


> That one looks like you already shoved it up your butt


Buttplug tube ?


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## fig (May 18, 2022)

EGRENIER said:


> Buttplug tube ?


I’d suggest socketing and experimenting until you find a _fit. _


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## Coda (May 18, 2022)

fig said:


> Mine arrived loose in one box. You must have bought the _premium_ discount grab bag.




I thought they were packing peanuts…


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## HamishR (May 19, 2022)

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.


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## jjjimi84 (May 19, 2022)

Harry Klippton said:


> Shove em up your butt!!!
> 
> 
> 
> ...


@Harry Klippton with the best advice that has ever been given on any forum.


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## benny_profane (May 19, 2022)

fig said:


> Yours came in boxes? Mine arrived loose in one box. You must have bought the _premium_ discount grab bag.
> 
> @vigilante398 left out this possibility...


Is there a breakout / adaptor board you _don't_ have? Convert a tube to a TQFP!


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## Feral Feline (May 19, 2022)

I got one of those tube grab-boxes, too.


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## Mcknib (May 19, 2022)

Oohhh a 4AV6

A double diode triode

Now that's a name and a half...

Just don't ask me what to do with it





__





						4AV6, Tube 4AV6; Röhre 4AV6 ID4397, Double Diode-Triode
					

Tube 4AV6 or Röhre 4AV6 ID4397, Double Diode-Triode, Miniatur-7-Pin-Base B7G, USA 1940 and Audio Frequency shown. Radio tubes are valves.



					www.radiomuseum.org
				




I'm attempting this at the moment from different noises


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## Chuck D. Bones (May 19, 2022)

peccary said:


> 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.
> 
> ...


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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## fig (Jul 16, 2022)

Chuck D. Bones said:


> 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.
> 
> ...


I’m just now looking through these, while at the same time trying to learn more about them in general. So to start, I grabbed a 9-pin socket and chose all that fit. I _did_ know that the first number of the PN is the filament voltage, and as Dave said, we don’t need no stinkin’ weirdo filament voltages [paraphrased], so I whittled that batch down to 12s and 6s (with one exception). This is that batch;

6U8A - Marshall-esque preamp?
6GK6 - like a EL84 with weird pinout
5687 - preamp tube
12B4A - could be nice

Now to test them. hmm…


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## Paradox916 (Jul 16, 2022)

That reminds me I got a bunch of tubes from my grandfather he was really into building HAM radios and 99% of of them I’m just to sure if they have any practical applications for me

I’ll try and post a pic of them later.


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## Chuck D. Bones (Jul 16, 2022)

I started testing mine, so far they all test "good."   I think most of these haven't been lit up in decades.  My TV-2B/U tester can't accommodate the 12-pin compactron tubes.  I haven't found test parameters for some of the more obscure part numbers.  A few tubes have the part # worn off.





Once upon a time, I worked with a couple of old ham radio operators.  They collected cool surplus stuff like this and they'd sell me their leftovers.  I think I paid $50 for this baby.  It's built like a tank.  Note the watertight gasket around the edge.


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## Paradox916 (Jul 16, 2022)

Well I guess I need a tube tester or just toss them back in the box, and forget about them for another decade or 2. There is some 12ax7, at7 and au7s in there but actually serviceability unknown, they are all US made so that gives some idea of age I guess… I don’t know if I really want to sort through these today… back i. The box you go🤣


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## Chuck D. Bones (Jul 16, 2022)

Good Score!

The US made small-signal tubes last forever.  For testing the dual triodes, you could breadboard the 1st stage of a Fender amp.  You'll need 200VDC or so for the plates.  If they bias correctly, you're in business.  Or just plug 'em into an amp and give a listen...


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## Paradox916 (Jul 16, 2022)

Chuck D. Bones said:


> Good Score!
> 
> The US made small-signal tubes last forever.  For testing the dual triodes, you could breadboard the 1st stage of a Fender amp.  You'll need 200VDC or so for the plates.  If they bias correctly, you're in business.  Or just plug 'em into an amp and give a listen...


I’m definitely keeping all the 12A*7’s out just to roll tubes, but the rest I probably won’t play with anytime soon.


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## fig (Jul 16, 2022)

I pushed the easy button. theBay had a 161 for $30.


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## Harry Klippton (Jul 16, 2022)

Send them to me?


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## Feral Feline (Jul 17, 2022)

I love the funky vintage tube testers, wish I could find such a score — more importantly, I wish I knew how the hell to use them if I should ever be so lucky as to have one cross my path.


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## vigilante398 (Jul 18, 2022)

I finally bit the bullet and ordered a µTracer kit so I could have a nice computerized tube tester and I put it together about 8 months ago, but haven't gotten around to boxing it so I can actually use it. When I finally do I'll get rid of my vintage tube tester for cheap. I think I paid $40 for it in 2015 and have more than gotten my $40 worth out of it.

The vintage testers you see around eBay are excellent for determining if a tube is good or bad and also useful for finding internal shorts in tubes, which as you can imagine are undesirable. The big things they can't do that I want is match power tubes tubes and plot response curves, and that's why I thought the $200 or so for a µTracer would be worth it.


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