I use two M100 since 1985 bass amplification on JBL 4350 (2231A 2X2).
Having been in the profession of HIFI at that time, I have tried many hardware and have never been satisfied by these M100 Accuphase. Unfortunately, these are very expensive amplifiers. Power still there, and at all levels, quality, or rather a perfect sound reproduction heat lamps with the dynamism of the transistors. WONDERFUL