Looking at your picture, you've got a MM 2475-65 Check out the model chart. http://www.pacair.com/mmamps/Misc__Info/Model_Chart/model_chart.html MM used the 65 watt power rating series in their first generation, which also used the 12Ax7 phase inverter. The 12Ax7 is on the left side in your picture too. Yours also has the original speakers, which are alnico, adding to the legend of your score. IF you decide to swap speakers for something lighter do not trash those speakers.
I didn't think what he has in it as stock speakers, were particularly heavy. Am I wrong ?? (OK if I am, I'm used to it).
Nice score! Looks like an early Music Man. Amp repair is not for the inexperienced. Unless you know how to safely discharge the capacitors, don't even think about opening it up.
SCORE! That was a continuation of Leo's work there. Have someone who knows that they're doing get it back into shape. Would love to see Uncle Doug do a video on this one
Yeah, I'm no expert on those alnicos either. My RD had a stock, mega-heavy ceramic, speaker in it. I bet the alnicos are lighter and pretty good sounding. Spec sheet says the amp is 60 lbs....not sure how much of that is speaker.
I have one of these, an early one with the blonde tolex, used on tour for years in the late 80s/90s and again in the early 2000s. They're quite strong clean, can get great tone, but I almost never used the overdrive in favor of pedals. If I'm not making this up in my head, I think solid state pre-amp chip is a 4558, same as used in Tube Screamers. Mine has the EV speaker, it's super heavy. It broke a few times over the years, somehow not enjoying being in a trailer in sub-zero weather and then loading in and turning it on... oops. They push a lot of air, MusicMans. Once about 20 years ago I was at Mercenary Audio near Boston and the guy Fletcher (famous hyperactive audio dude, no longer there I think) showed us these MM stacks that he had used recording Aerosmith albums, they placed the speaker cabs facing each other with a ribbon mic in the middle, put one out of phase with the other and measured distances and cranked it to get guitar tracks. He said they went through speakers, but I don't know what he had in the cabs.
You got a great deal ! I got my MM dead, and had to bring it back to life. Still replacing caps, tubes, and flyback diodes, I think I only had about $100 in parts! I've read that the early ones used the LM307H op amps. My 81 RD One Hundred uses the TL072's, and I seem to recall 1 LM1458. Much discussion on the MM forum indicates chip swapping doesn't improve anything.
My music man 2x12 150HD was the loudest and best sounding hair straightener I ever had. So, why did I sell it and buy a Vox AC15 C1. ......? ...as I got older I just couldn’t pick it up and put it in my car boot any more!!! ............and now I’m down to a Katana........same reason. So, young man, get it fixed and use it while you can. You’ll never sound better,. Good wishes Mick
Too cool man! That amp for only $FREE.99? I've done my own amp work before https://www.strat-talk.com/threads/noad-pic-heavy.317670/ but if you don't already have some experience working on circuits I'd leave it to a pro. As others have said, you can mess yourself up pretty badly if you don't take the right precautions.
free is a real deal on that amp ! I played though one that had 4 ten inch speakers like a super reverb . Definitely worth getting fixed right !
Definitely take it to your best local tube guitar amp and have it gone through. You will not be disappointed. It’s much better than any new amp under $1500.
Just an update. Brought it to my amp guy and he got it back to life in a day. Amazing amp. Really excited to dig into it.
Wow , you got a deal there ! Glad your tech got it done quickly . You're lucky you got a light ( ? ) one , according to the chart Joe sent above , my 212HD130 weighs 93 lbs. ! I knew it was heavy back in the '70s , but I was a younger man too !! Enjoy that sucker !!
