Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: floyd on December 10, 2013, 12:46:14 pm
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I gutted this non-working 2-12 Peavey tube hybrid , ( tube output , solid state pre - amp ) years ago , and finally got around to building something worthwhile in it... a 1-12 , 35-ish watt , cathode biased AB763 with reverb. I used an Allen SR power trans and a smaller Allen Bandmaster output trans. Then , since it's snowing outside , I went with an EVM12-L for adding weight to the rear end of my '86 station wagon. Wonder tone !
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Looks Great. How does it sound and operate. With 35 watts it must be two 6L6's with something like a Super Reverb/Bandmaster AB763 circuit? I did the same thing with a Peavey Pacer SS amp and went with the Deluxe Reverb AB763. Platefire
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First , I dropped the PT voltage from 340 to 320. Then I used F&T caps ..series 80uf for the main , then 22 uf for the screens , then 16 for both the phase inverter and pre-amp. Believe me .. there's no "ice pick " in this build.. very smooth , even the breakup is nice. Mallory 150s' and silver micas' throughout. VERY pleased , and maybe a little surprised by the warmth. Sorry , yes, 2 x 6L6s' and GZ34 .. typical AB763.
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Looks pretty good! I like these stories about tubing up old Peaveys...I actually got a Bandit for free because supposedly it didn't work...but it did! Now I don't that much want to take it apart even though it's (all) SS.
Generally, SS amps have pot vlaues quite a bit different from those req'd by a tube amp. Did you change those out or were you able to re-use? (I suppose I could look at a schemo to find out)
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I did away with every thing but the nice aluminum chassis and the cabinet , ( and made a new baffle board ), although I still have the Peavey transformers here for whatever reason. The original pots were PC mount , so I would not re-use those.
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Nice job. I just love it when people recycle. I have done that to several amps myself.
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Yeah man....very cool.....looks real nice now
We'd love to hear it if you get a chance
I gutted this ............. years ago , and finally got around to building
Congratulations on that alone........we've all got those type projects laying around
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Nice clean build you have there. I've been scouring CL for a suitable cheap donor chassis to re-purpose for the same amp you built except with fixed bias. Gutting a cheap solid state amp is less expensive than buying a new combo cab and chassis.
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:thumbsup:
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"Gutting a cheap solid state amp is less expensive than buying a new combo cab and chassis."
Profoundly. I have been looking on CL for dead amps and found fairly few, in fact, none, other than the one I found. (A Peavey Bandit which was free...said wasn't working...problem is staticy pots only!) I imagine this has something to do with people not wanting to go thru the "take a chance and meet someone" ritual for something they know is in bad condition. My suggestion, especially if you wanted to build several of these, would be to place a "$25 reward!" ad for a dead amp or two, or to call a few local music stores to see if they have any carcasses. I would bet you that virtually every music store has a carcass they have unable to fix lying around. Can't hurt. You don't have to accept what's offered. Who knows....you might even get an old tube amp!
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Did anyone notice in the gutshot photo , the most important tool ? ... a chopstick !
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Impressive job, nicely done! Cool.
I am somewhat "biased" towards cathode biased also. Using 270 ohm resistors, I can switch between 6V6's and 5881's in two of my builds with no problems at all.
with respect, Tubenit
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Very nice looking - where did you get that grill cloth, it looks great with the black tolex.
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Mojotone Fender oxblood grillcloth