I Meant: Any Amps with 7868 tubes? (2024)

I was curious if anyone here has any amps with 7868 tubes.
I believe that some Ampegs had them.
I think that they were also used in the old Fisher audio systems.

I have 2 Sound amps from around '67-'68, both with 7868 tubes.
They sound great, but you really have to crank them to get any serious grind out of them.

My Gemini I with 7591's will break up but needs to be hit pretty hard to do it. Jumping the channels helps with that too. Mine didn't have the original P12Q in it when I got it and now sports an Italian C12N, so not much speaker breakup being added to the equation with mine. Like I said, it will break up but it's not likely to be mistaken for a Valco. I've used it out when I needed a warm but clean tone at reasonable (drummerless) volumes. That it does very well.

I do have a P12Q in a box somewhere and have been meaning to stick it in my Gemini just to hear the difference.

Heritage 80 said:

But also keep in mind that Everett didn't see any reason that guitarists would need to turn their amps up over half volume and the Jets and Gemini 1's in particular get pretty rocking when cranked up. That said, based on my experience the 60s Ampegs with 7591 tubes break earier and with more grit than those with 7868s.

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The way an amp breaks up is very much a function of the circuit, and not really dominated by the type of power tube. The 7591 tube is electrically identical to the 7868. The only difference is the base and socket type. I made up a set of socket adapters so I could plug 7868 tubes into my old Capitol amp, instead of the 7591 tubes. The amp sounds identical. These tubes are 19 watts, which puts them in between a 6V6 and a 6L6 in power output. They are also easy to drive to full power output with a low signal voltage swing - in other words, high sensitivity. My Capitol amp has glorious tone.

"The 7591 tube is electrically identical to the 7868. The only difference is the base and socket type."

Incidentally, there's a third type that's also essentially identical electrically to 7591 and 7868 except for base and socket, the 6GM5. The latter has a 9-pin miniature base, like EL84. Anyone got a guitar amp that's stock with 6GM5s?

That Capitol looks like fun!

chuckNC said:

Can you jump channels on those, Lou? Reverb and Trem?

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I never tried jumping channels with them.
I haven't run them in a long time, and I should get them checked out.
I should also get them properly grounded.

Diablo1 said:

The way an amp breaks up is very much a function of the circuit, and not really dominated by the type of power tube. The 7591 tube is electrically identical to the 7868. The only difference is the base and socket type. I made up a set of socket adapters so I could plug 7868 tubes into my old Capitol amp, instead of the 7591 tubes. The amp sounds identical. These tubes are 19 watts, which puts them in between a 6V6 and a 6L6 in power output. They are also easy to drive to full power output with a low signal voltage swing - in other words, high sensitivity. My Capitol amp has glorious tone.

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Nice Capitol amp.
I have to get those 2 amps up to snuff.
They're in NY and I've been in Chicago for a few years, so it hasn't been easy to maintain my guitars and amps.
I'll be in NY next month, I'll get some better pictures of them.
I can't remember what speaker is in the combo, though it is original.
The 2x12 has the original Jensens in it, can't remember which ones.

loufed52 said:

Nice Capitol amp.
I have to get those 2 amps up to snuff.
They're in NY and I've been in Chicago for a few years, so it hasn't been easy to maintain my guitars and amps.
I'll be in NY next month, I'll get some better pictures of them.
I can't remember what speaker is in the combo, though it is original.
The 2x12 has the original Jensens in it, can't remember which ones.

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Say Loufed52, if you bring your amps back to Chicago, and are looking for someone to fix them up, I could do it. I rebuilt the Capitol amp after I bought it DOA. No schematic was available, so I had to trace the individual sections to understand the design. I started with a recap and grounded power cord, and found a couple of open resistors and a shorted rectifier tube. PM me if you want me to work on your amp. Do you have a schematic for your amp? If so, post it up or a link if it's on line. Also, do you have any other information on the manufacturer of Sound amps? Where they were built or who designed them etc.? I'm pretty sure my Capitol was built by Lectrolab in Cicero IL. They also built amps under the name of Sound Projects.

Diablo1 said:

Say Loufed52, if you bring your amps back to Chicago, and are looking for someone to fix them up, I could do it. I rebuilt the Capitol amp after I bought it DOA. No schematic was available, so I had to trace the individual sections to understand the design. I started with a recap and grounded power cord, and found a couple of open resistors and a shorted rectifier tube. PM me if you want me to work on your amp. Do you have a schematic for your amp? If so, post it up or a link if it's on line. Also, do you have any other information on the manufacturer of Sound amps? Where they were built or who designed them etc.? I'm pretty sure my Capitol was built by Lectrolab in Cicero IL. They also built amps under the name of Sound Projects.

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If I remember correctly, they were built by a small company on Long Island, NY.
As far as I know, the company never sold much beyond locally.
I've never looked for a schematic, maybe I'll do so.
I may be moving back to NY soon.
If I don't, I will bring them to Chicago and contact you.
I have a few 7868 tubes stashed too.
I'll get more info off them next month.
Thanks-