The 80’s era ARC tube amps are generally superb. I used a ARC D70Mk2 for several years with a CAT preamp and the match was one made in heaven. Today, the ARC has been replaced by what I consider to be the best lower output tube amp on the market...the Jadis JA30Mk2, BUT it took this mono block amp to better the ARC from the 80’s.
The ARC had a criminal system for biasing, which is why i went away from it, but if it did not have this issue, i suspect i would still be enjoying it.