Old ARC tube amps

I think that you'd be better of with old Mac stuff rather than ARC.
IMHO I was not impressed with vintage ARC amps at all.

McIntosh Has never made an amplifier, including the very good MC-60 and MC-225, that was in the same class as the D-76 or D-150 Vintage from a sonic standpoint. Construction wise, though, MAC is hard to beat.

I am with Frap on this one, I have heard very few tube MAC's that I thought sounded as good as Audio Research, though I am fond of the 30's and the 230's, but that was before Audio Research was founded.

Those ARC models are a good choice. I owned the SP-3a and D-76a combo in the 70's and upgraded to the D-150. I was seriously considering the MAC line but with head-to-head the ARC was better hands down. For old times sake I picked up a D-150 and it still sounded very good. One caveat. The power supply capacitors should probably be replaced due to their age. I had this done on the D-150 and it certainly improved the sound