Apt Holman repairs

The person to contact is Bill Thalmann at Music Technology. Bill is a former engineer at Conrad Johnson. He still does repairs, rebuilds, mods, and upgrades to CJ and most other brands; both solid state and tube. He has upgraded the power supplies on two preamps for me, as well as doing a few internal tweeks.

See this website link

http://www.musictechnology.com/services.htm

Bill's email is bill@musictechnology.com

You could also try Stan Warren of Supermods. If you don't know Stan, he was one of the original founders of PS Audio (the PS stands for Paul and Stan). He later founded Superfon. Stan still builds preamps and would probably be glad to give your preamp the once over. Stan can be reached at (541)344-3696. Best time is 3pm to 7pm pacific time. Stan has done a few digital mods for me.

Just from searching (since I have the pre-amp and amp), not from experience)
https://audioproz.com/AP.php?Article=64https://audioproz.com/AP.php?Article=95
https://quirkaudio.com/?page_id=895https://quirkaudio.com/?page_id=952https://quirkaudio.com/?p=936

A vote from me for Audioproz.
The owner and head tech, Vince, worked for Apt-Holman ( mine had been originally signed by him) and he has a few upgrades he does during repair.
He is an interesting person to deal with, not much for fuzzy, warm small talk but has repaired an array of things for me and always done a very good job.
Z