ARC M300 MKII call for help

Amps of that caliber not repairable?

Not a plus for that company.

Not only ARC company can't repair anymore amps. Pretty much all of them slowly declining. No new techs and old techs aren't forever.

Greg Christensen was the responding repair team tech. He still had a record of a 2016 servicing of one of the mono blocks. Thanks for the suggestions. I will pursue and report back. Here is the correspondence from ARC.

Dear Scott

Summary: I see your amplifiers were last here in 2016 according to our records. Unfortunately we are no longer able to provide parts or service for the M300 or M300 mk2. Too many of the parts used in that model have become obsolete and we do not have modern replacement parts that will work in that design. I'm sorry to have to give you the bad news but I'm afraid we will not be able to work on this unit for you.

Thank you,

Greg Christensen
Audio Research Customer Service

Just spoke to High End Audio Repair in Brooklyn. They also do not repair the M300’s anymore, siting their weight as the determining factor. Bummer.

Try to contact John Rutan at Audio Connection in NJ. He’s a long time ARC dealer and might know someone who can fix that amp. 
https://www.audioconnect.com/