hifi engine

SX-990



SX-990

This is my electrically restored SX-990. A friend got it for me for cheap in excellent physical shape and it was working. I was going to keep it in original condition but things began deteriorating quickly. Transistors became noisy and the tuner had an odd behavior, which turned out to be the 4.7uF cap at the output of the detector had gone completely open. This prompted me to restore it. This one was new in 1969, uses LM703's in the IF strip and a Motorola MC1304 as the stereo decoder. The fuse style lamps and dial pointer have been replaced with LEDs.