Musical Concepts amplifier modifications upgrades

It appears that new driver boards are limited to the Hafler Power amps at this time, but I think they were once available for the Adcom power amps also.

He does do upgrades using his MC-3 circuit board on certain Adcom preamps as well as outboard power supplies, though.

I have a Musical Concepts modified Adcom 555 John did for me back in 1989. After reading the review in Absolute Sound ( Volume 13,Issue 55,1998)by Frank Kaplan I pulled the trigger and sent it in for mods. Unlike the one in the review I had mine turned into Dual Mono with Dupont Teflon caps and the Platium mods plus Edison Price copper binding posts. It came back sounding like a warm tube amp,gone was the edgy highs and the bass was tighter and more controlled. This amp has driven Vandersteen Signature 3's,Infinity RS3B's and Odyssey Lorelei's with no problem. I still have it and pull it out every once in a while and fire it up. I used it with the Adcom 750 pre amp that Musical Concepts modified to platinum level and it sounds very open,extended an imaging is dead on. 
I doubt you would be disappointed in the money spent vs. results.
Yes I moved on to a pair of Plinius 100's mark 3 in mono mode but the Adcom has a sweet spot in my heart even today.

Realizing that my Adcom 555's are nearing 30 years old, I was just looking at having the capacitors replaced. After doing research
 on line I found a few really good techs out there that will modify  older amps. Musical concepts looks like one of the best. Thanks for your review.

Something to ponder,if you send them to John ask if he can put a I.C.E.on them so you can use power chords of your choice. Good Luck.