Musicman 410-75 amp question....

Just picked up a beautiful condition 410-75 musicman amp at a guitar show....sounds AWESOME and is all original with footswitch.
Couple questions...is it a self biasing amp in the sense that as long as you use matched power tubes you don't need to rebias it? What speaker load should the amp be set to on the back with these 4 original ceramic speakers? (I will check to see if they are wired parallel or parallel/series....)
Thanks!

Hi Keith - nice find!
Music Man amps are not self-biasing. When you install a new set of tubes they should be matched to get the most headroom before clipping, and the bias should be checked and adusted as necessary.
A 410 combo should be set to 8 ohms (assuming that the speakers and speaker wiring are stock).
Cheers,
Lars Verholt

Keith, just to chime in, I recently found a damaged MM-75 head at a garage sale and cleaned it all up. I play it through an MM 1-15 cab with an Eminance Legend speaker and it is the most beautiful sounding amp I've ever owned, possibly ever heard. I don't know what they did to the 75s but they are superb. I've tried a few different tube sets and they all change the voice but all sound great. At the moment, I'm sticking with the old Fender 6L6s it came with. You found a truly fine amp.