Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: nateflanigan on January 23, 2011, 03:35:54 pm
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Hey folks,
I picked up one of those little solid state vox cambridges cheap on craigslist. It's an attractive cab and a decent sized chassis so I thought it'd be a good rebuild candidate. Thinking I might want to do something like a vibro champ but with an el84 like Doug's schedule 40 and possibly a 1 tube reverb circuit. I have a few questions though...
-Will the standard champ PT handle the extra tubes or should I go with something else?
-I know that the 1 tube reverb circuit works with the tank that doug sells, but I'd need to get one of the shorter one's. What input impedence am I looking for? tubes and more sells this one which would fit nicely...
Reverb Tank - Medium Decay, Short Tank, 8DB2C1B
310 ohm input, 2,575 ohm output, medium delay, horizontal, open side down mounting. Used in Marshall™ amps.
Outer channels measure 9.25" Length x 3.375" Width x 1.313" Height
RoHS Compliant
Any design suggestions would be nice, I'm not really concerned about keeping the amp voxy sounding.
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Your tank input needs to be 8 to 10Ω
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Thank you. Looks like a type 8A*** would do the trick.
I did the math for the PT and it seems ok. Heaters for 3) 12ax7 and one el84 should be 1.66a, with the trannie rated at 2a so that's just over 80%. The high voltage should be ok too.
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Hi Nateflanigan, Sounds like a good home for a VJ HOT ROD. I picked up a Valve Jr. cheep and was undecided what to do with it as it played well as it was. But being unable to help my self it had to be tweaked, so i found a schem for the VJ HOT ROD and it was an easy add on to the existing PCB. I also required a short tank (8AB2A1B) @ 10ohms to fit the small combo cab. I had no idea the sound this would produce being a short tank ,i was rapped that it was more than enough for a small amp.Thanks