Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Beezerboy on October 14, 2023, 09:03:51 pm
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So, my friends G60 shat the bed. power tranny primary is open. I've been searching for a replacement but no good yet. Pig is apparently now owned by Arai. The Pig website doesn't any list parts and says that no order will be filled anyway.
I did a quick check of Hammond and don't see an obvious replacement for this weirdo tranny. output primary is 370 going to the solid state rectifier. it needs to be about 200 mA. the OEM is not center tapped though I guess a guy could work around that. it also needs the 6V heater at about 3A.
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How is this different from any other two-6L6 amp?
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Catalog pages here:
https://www.hammfg.com/electronics/transformers/classic/290?referer=1101
This should work. You'll likely need to fabricate a mounting plate.
https://www.hammfg.com/files/parts/pdf/290EBZ.pdf
Odd; first guitar amp I've seen with R core transformers.
--Pete
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Replacements can be found for all transformers.
The real problem is the physical, mechanical installation
G60 circuit;
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Something appears off to me. 360V at 110mA is 40VA. Seems a bit small for 6L6GCs. Also, 3A and 4A fuses on the primary of a 40VA PT seems a bit big. Could the 110mA on the schematic be in error or am I missing something?
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Something appears off to me. 360V at 110mA is 40VA. Seems a bit small for 6L6GCs.
Right , it is good for 6V6
Fender Deluxe Reverb ; 330 V at 120ma
Tremolux / Vibrolux with 6L6 ; 325 v at 180 ma
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A toroidal option. https://www.antekinc.com/as-3t350-300va-350v-tube-transformer/
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A toroidal option. https://www.antekinc.com/as-3t350-300va-350v-tube-transformer/
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This is a Fender Bassman 5F6-a, but solid rectifiers and funny mounts. R-core is odd but there seems to be space for normal iron.
...40VA. Seems a bit small for 6L6GCs. Also, 3A and 4A fuses on the primary of a 40VA PT seems a bit big. ...
The primary fuses are so you don't burn-down your house, not to protect a lowest-price amplifier. Burn it up, buy another.
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So, my friends G60 shat the bed. power tranny primary is open. I've been searching for a replacement but no good yet. Pig is apparently now owned by Arai. The Pig website doesn't any list parts and says that no order will be filled anyway.
I did a quick check of Hammond and don't see an obvious replacement for this weirdo tranny. output primary is 370 going to the solid state rectifier. it needs to be about 200 mA. the OEM is not center tapped though I guess a guy could work around that. it also needs the 6V heater at about 3A.
Did you ever replace the OT? If so what did you go with? Mine has been dead for a few years and I’ve been holding onto it hoping I could find a replacement. It’s my all time favorite amp.
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Too often the authors do not come back to us with the solution found or the sequel.
It would help other members
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sorry for the late reply. I put in that toroidal trans and it worked but the amp has other problems. lots of noise that I assumed is due to old failing caps. I asked the owner what he wanted to do... like do you want me to re-cap it? he said no. I put it on the back burner. he has aspirations of building an amp and use the Pig's hull as a base. I suggested a blackface AB763 and offered parts etc because I have them, but it turned to summer and there are other things to do. so it sits... taking up space in my shop. he called 2 days ago.... now he wants to do a 5E3. like a whole Mojotone kit. that might be good because that is an easier thing and he is fairly handicaped electrically speaking. wants to learn but I have reservations. as for the pig is in stasis. I have my own projects