M-2
B-5
(1980 - 1983)

All things must pass - gone were the V-FET, long live the High-fT !

High-fT are made of multiple miniature transistors connected in parallel, offering lower switching distortion and a high frequency cutoff (High fT) up to 80mHz, thus offering better linearity.

Just like Sony, Yamaha dropped the expensive Vertical FETs for cheaper ones... which Sony used as well in many of its own units, from the 1978 pre-Esprit TA-N86B onward. Just as for the VFETs, both Sony and Yamaha touted that the High-fT were exclusive designs of their respective R&D labs :-)
Released in Japan as a B-5, without the meters. A very healthy power amplifier anyway, with a key word: p o w e r.

According to this eBay auction, Blaupunkt made a rebadge of the M2. Some parts look similar but not that similar... anyone can confirm this?