Yamaha's other statement along the NS-1000M.
Awe-inspiring, unbelievable sound, magnificent design - a true landmark. Filled with 4 of Yamaha's 1st generation VFET power devices: 2SK77, enclosed in a bigger-than TO3-box. Unlike the later B-2 or Sony's units, the B-1 doesn't use complementary pairs of devices, giving a more complex pre-driver circuit but making it easier to find matching devices. Also available very briefly at the end of the production run in silver color.
Complemented by the optional UC-1 controller which ads some fairly non-useful features like the ability to switch 5 pairs of loudspeakers at a distance or huge VU meters. Never mind the meters - just plug the amp and enjoy.