This was a fun and interesting project. Came from Division Street Guitars in Peekskill, a great lil' shop run by my good friend Paul Decourcey. When it came to me it was, well, truly a barn find. Translation: absolutely disgusting. Barns are no places for instruments and definitely not a place to store an amplifier. This amp was badly water damaged on the bottom with plenty of mud to prove it. Some of the plywood had separated so much gluing and clamping was needed. Very time consuming and rather educational. I never realized how many layers of stuff are between the wood and the tweed exterior. More than I thought! And I also know, I'm not the man to do a re-cover job. Used a lotta Simple Green on this one.
He bought it on Reverb from a store in the midwest as a project amp. At least 2 other very good techs turned down working on it. I don't blame them either. If I wasn't a little nutty myself, I may have made the same choice. Amp was full of dead egg sacs from some unknown bugs and some of the wires had been chewed by mice. First order of business was to use a couple cans of compressed air outside just to get the nasties out. Next was the black mold. That and the mud is where I used a lot of Simple Green and a lot of towels, old toothbrushes.....gross man.
It also came with a replacement output transformer that was nice, but the wrong type. This amp had the transformer mounted to the speaker originally, but that old Jensen was long gone. So since this amp is so ugly and we're not re-tweeding it, we decided to just make it player friendly. I replaced the output transformer with a Heyboer tweed 8 ohm Bandmaster transformer availble through Mojo Musical Supply. Not terribly expensive and they are fantastic sounding transformers. I believe Mercury makes the proper '51 Pro part but it's much more expensive and we want to keep this amp affordable for re-sale. And truthfully, I like the Heyboer Iron I've used a bit better though my own amps are loaded with Mercury.
Power transformer was the original Triad. Bakelite fuse holder was broken in half and the power cable and switch were done. Replaced all that and grounded the poor thing!
No tubes came with it. Had to buy 3 6SC7 tubes. A word about those: at this stage of the game, they are risky to purchase. Most of the remaining tubes suck. A decade ago when I was really doing this I could buy a dozen for $60, reject 1/2 of them and still make my money of the remaining ones. Now they set me back at least $18 a bottle. Most I come across are microphonic or have a good hum going on. This one 2 outta 3 were passable, the third I used as the phase inverter. RING! It works but I advised Paul to get another one or buy a 6SC7 to 12AX7 converter on EBay. Other octal preamp tubes are plentiful, like the 6SL7 or 6SN7. For some old Gibson amps 6SJ7 tubes are cheap and plentiful. But, I'm not rewiring this amp for those.
The filter caps were all leaking. They had to go. Don't even bother turning an amp on with those old caps still in it. Throw them away right away. All the electrolytic caps had exploded in this amp. Also the original signal caps were all leaking, badly. I use polyester Orange Drop Spragues in the phase inverter and my favorite Mojo Dijon caps in the preamp. The input caps I left alone. No DC on those so why bother. I'm sure they leaked when they were new but that's a part of the sound so, leave them be!
Also replaced the power resistors with 10k 5 watt wire wound types and the load resistors with carbon composition like the originals. Amp was making those telltale spitting sounds. It's dead quiet now.
When he got the amp it had one of those ugly ass 70's Disco square magnet heavy 15" CTS speakers that belong in an Ampeg cabinet. Nope! Not for a tweed amp! Paul fortunately had this beautiful sounding and great looking Jensen from a 60's rather useless Epiphone amp that lives in his window. He bought the thing for the "someday I may need this speaker" factor. That someday is today and this amps just gives up a beautiful tone now....
It really needs a Telecaster. That is what this amp was built for. My '58 Jazzmaster loves this amp as well. That's a combination from heaven. Big, warm with lots of bite.
Nice and simple 2 channel amp with a single tone control. One channel is nice and dark and is set up for a microphone, the other has plenty of bite. Whenever I get a chance to show a Mesa Channel Switch reared youngster one of these amps I take it. They usually plug in and wonder where the 27 other knobs are but when they start playing something always happens: they start playing better. More grit? Turn the tone knob up and play harder. More clean, back off that pick.
I wound up bolting the new output transformer to the chassis and adding a 1/4" Switchcraft jack so you can plug this amp into any 8 ohm cabinet of your choosing. Also this amp is cathode/self biasing. You can simply drop in any matched pair of 5881, 6L6 or KT66 tubes of your choice and jam out. That's the fun/madness of these early tweed amps. Endless choices! You can make decisions about your tone on the fly. New amps they pretty much make the choices for you. No thanks. But ya know, those new amps are good for getting you there. A real amp like this is good for the one who has already arrived dig?
Mandatory photo with a Tele:
So if you want to see this amp, hang ten and make the drive to Division Street Guitars in Peekskill NY. Great shop and Paul may even sell it to you!
JB
