6U10, 6AC10, 6D10, 6AV11 Tubes

[zozoe]

Greetings,, Are the above titled tubes, & others like them, interchangeable in the precise sense the 12**7's are swappable with a resulting change in gain? Or is there too much 'other' stuff going on in those compactrons? In particular, My Ampeg C-12 calls for a 6U10, as do many, many Ampegs, and I wanted to know if the other Compactrons mentioned are drop in substitutes that may offer different, or more, amounts of gain?

Many Thnx, Kenny ॐ

[sluckey]

The pin outs are the same.

[Stevem]

The pin outs are not all the same .

I went thru this type of thing 15 years ago when I made a compactron adapter/ selector to allow testing of these tripple triodes on my Hickok 600 tube tester.

A 6U10 and a 6D10 are not the same pin out.

One is a 12BY type base and the other ( the U10) is a 12FE base.

The first triode in a U10 is a medium mu 17.
The second is a high mu 98.
The third is a medium at 17 again.
So a U10 is like two 12AU7s and a 12Ax7 in the same bottle.

Pin out wise there are no other compactrons that will just drop in without rewirering the socket.

I guess your best shot is to see if you can get a hold of a few 6K11s which is one medium mu and two high gain mu sections .

You will need to re-wire the socket then like my chart shows here.

[martin manning]

Compactron Rosetta stone.

[zozoe]

"I uess your best shot is to see if you can get a hold of a few 6K11s which is one medium mu and two high gain mu sections .

You will need to re-wire the socket then like my chart shows here."

Thanks SteveM,,, curiously, what would such a swap from a 6U10 to 6K11 offer in the end.... higher gain, given that all other parameters differ solely in the pinout? It's nothing i'm truly thinking of doing, but very curious....... Thnx, Kenny ॐ

[sluckey]

The pin outs are not all the same .
A 6U10 and a 6D10 are not the same pin out.

They certainly are the same pin out

[Stevem]

Thanks for the list Martin!

Yes the pin out is the same between a 12FE base and a 12BQ base but for pin 8.

Pin 8 on a 6U10 goes no where, however pin 8 on a 6D10 is a internal shield, so where talking 6 of one and a half dozen of the other type deal.

[FUCHSAUDIO]

I've thought for a long time about making an adaptor for putting a 12AX7 or whatever number would work best, and an LND-150 fet to cover the third triode section and be done with it. You might even do it all FET's.
You could change the socket to a 9-pin in some models (except most Ampeg's have them on PC boards), and add a FET inside the chassis (which I did a few times), but I'd love to make a plug in of some kind.
Unfortunately, I just don't see enough units to justify designing and making it. PLUS: There are multiple pin-outs for the compactrons too...oy.

I did the tremolo and vibrato modules years ago (and they still sell regularly), but that wasn't as big a project as this compactron adaptor would be.

[Stevem]

That's interesting!

Another way to go might be to install a 9 pin socket in place of the 12 and set that up to take a 12DW7, then drill the chassis for a 7 pin socket and run a 6AU6 set up to run as a triode, or maybe keep it a pentode if looking for a bunch more gain.

PS, I think a 7274 is also a disimlar 9 pin duel triode?