Tube Amps needing mods. Needing a referral for the work.

Leave them be! Mods will harm the resale value.

I think if you don't like how they sound they're probably not the right amps for you. Alternatively, ARC stuff is super sensitive to pairing so it could be that your preamp isn't a good match. Either way, rather than mod a fairly expensive unit I'd seek better pairing. Sometimes it takes a few tries to get things right in a system. I tried an ARC preamp and while I know it's a great unit as I've heard it sound great elsewhere, it didn't work for me. 

I don't know the amps- I owned ARC in the early days. The company does (or at least used to) have authorized repair facilities in different cities. I believe Pyramid in Austin is one such place. 

I really don't like shipping tube gear, so assuming you want the amp recapped and gone over-- have no idea what "mods" you contemplate- you might reach out to Pyramid and take a drive with some muscle to help you. 

I have a fellow I use here for vintage tube gear- his main thing is antiquarian (pre-WWII) and he is especially good, but will not work on anything that isn't pure tube stuff- no hybrids as far as I know. 

Back in the day, I did have ARC in Minneapolis  do some mods to my SP-10mk ii. Those were factory sanctioned and because I was offering to be a crash test dummy for a couple things- like gel tube sockets, they were willing to accommodate. Haven't dealt with the company in a long while so can't speak to their current policies re "mods." 

Best of luck,

Bill Hart

Thanks Whart,

Yes that caps need replacing. And thanks for the suggestion in reaching out to ARC to ask for someone authorized.

David