In my humble opinion, replace the original ARC tubes by NOS tubes. Most remarkable improvement is the repalcement of the 6550 by a Tungsol Blackplate 6550. See discussion on audiogon
Mods for ARC preamp / amp
There's a company called Great Northern Sound advertising on Audiogon saying they can do some pretty amazing mods on ARC gear. Has anyone out there used them? Were you satisfied by their work? I have an Arc ref 3 / ref 110, before I consider handing them over for a mod, would really like to hear from all of you. Thanks.
Erik
Erik