I've owned two pairs of TC-50's and am a fan.. I had used a Forte 1a until it blew one channel.. so a 4a would work too.. They sounded best when hooked up to a tube amp, can't remember which one, possibly a quicksilver (this was at a dealer some years ago) I have been using my TC-50's with Cardas Golden Hexlink 5c and a rega Mira with, in my opinion, good results. Rega Vulcan sub seems to be made for the TC-50's also, good results very versatile.