Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on August 22, 2022, 08:41:26 pm
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Look at this beautiful amp! It has the original brown base Mullard EL34 tubes. Original case cover and foot switch. Don't know if there is a way to date the Belkins storage sticker. To late to remove chassis tonight. Just need's a general check out. Ok i can here it now! :l2: I quess it's Sunn fever? Definitely a blessing. Will check it out in the morning.
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Edit... removed link to wrong schematic. See reply #11 for correct schematic.
That's from about '68 or '69. It has the original early style grill cloth. Biggest combo amp I ever toted. The last band I played with had one. The Solarus changed to piggyback in March of '69. Grill cloth changed too. I currently have a Solarus 2x12 cab to go with my Sceptre head. This is what the newer '70s grill cloth looked like...
(http://sluckeyamps.com/6v6plexi/P-6V6_09.jpg)
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Oh, yeah... You'll like the looks under the hood much better than the Model A.
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The Sunn Sonora was a matching bass amp companion. Same size, same power amp, different preamp.
https://reverb.com/item/1203409-60-s-sunn-sonaro-bass-guitar-amp
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Oh, yeah... You'll like the looks under the hood much better than the Model A.
I'm sure i will like the underside of this amp. The Model A was my first Sunn experience. The design was a nightmare layout wise. The best part of this is i don't have to lift another cab on the bench to get the chassis out and back in. I'm going to like checking this out. It's like brand new under the Sunn cover.
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You got the cover too? Wow! What a find.
Hopefully everything works.
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Your right! What a find! Look at this sweet circuit! Having problems with my phone camera.
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Get's polarity switch out of circuit.
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trem on those is nice but dang i can't imagine a time when the engineers said "we need a three gang pot" and the MBAs didn't counter with "no you don't, you get ONE GANG"
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> the engineers said "we need a three gang pot" and the MBAs didn't counter with "no you don't, you get ONE GANG"
I think there was a time, a few years, when Conrad was the Head Engineer *and* the Chief Financial Officer.
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> the engineers said "we need a three gang pot" and the MBAs didn't counter with "no you don't, you get ONE GANG"
I think there was a time, a few years, when Conrad was the Head Engineer *and* the Chief Financial Officer.
Agreed. And those early Sunn amps were built with high quality in mind. Bean counters were not yet in the picture. That 3-gang pot gives a prettier LFO signal with a more constant amplitude over a wider frequency range. Spend the money and do it right. Add the cost to the price tag. People will pay for the quality.
I have a passion for the Sunn amps from that era. Not so much for the later stuff. I'm always happy to see another one brought back to it's glory.
Nice pic BTW.
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I just realized the schematic link I posted in reply #1 is for the later head version with 6AN8 PI and 6550 output tubes and bigger iron. Your amp should have a 7199 PI and EL34 output tubes with smaller iron. Here's the correct schematic for your amp...
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plexi50, that is an amazing amp in incredible condition.
That's the first time I've seen bright caps across input grid stoppers. And, five components soldered to one pin (#7).
Thanks for the photos!
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That's the first time I've seen bright caps across input grid stoppers.
Doesn't that defeat the anti-RF effects of the grid stoppers?
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Now it's a waiting game on the Capacitors to get here. I have another amp that is if not one of the King's of amp's. Posting that one in a few minute's. Surprise!