I've tried many receivers and several ss amps including the M-50, Kenwood 6004 and my MC-2505 with my Altecs. So far none of them come close to the wonderful sound I get with the MC-275 tube amp. Altecs just sound better with tubes. It's what they were designed for originally. I listened to and loved mine since 1966 and only had the tube amp working for a year. I miss it and finally have a line on a local repair guy if I can ever get in touch with him.
As for the Luxman I think they are top notch amps so it should sound good with it. If I had never tried the tube amp I would still be happy with the 2505