Wilson Shen is definitely servicing his amplifiers. I purchased a pair of his M100’s, and immediately sent them to him (yes, in St. Louis). He got them back to ‘new spec’ status, and I asked him to replace the red led’s with blue ones, probably the only Clayton mono’s with all blue led’s in the universe. All my other gear have blue led’s, and personally, I just prefer the blue. These M100’s are simply fabulous. Overall tonality is absolutely beautiful, a touch of richness, without being syrupy. Bottom end is deep, uh, maybe I should say DEEP, and tight, and punchy (when recorded that way). Midrange, is gorgeous. The top is extended, but never bright, or harsh. The best thing about the Clayton amps is the soundstage. It is airy, and HUGE. This is solid state at its best.