I use this amp in 1988 I bought used in 3000 en era it was $ 15,000 fr the release date in 1981 is an exellent prvu amp originally for home associated with a prampli.
the distortion is almost no breakdown by cause I fin addition to the fan with fan fly by.
Power 2 x 250 w into 8 ohms double blind and 4-ring capacity of large value rich bass.
RCA AC and DC adjustable gian on the back
I use it as a backup amp indestructible life guaranteed by Yamaha.