QS100 4-channel rear amplifier/decoder.
Replaced all electrolytics and small transistors, fitted LED illumination for the meters, fully serviced and adjusted.
The power amplifer of this QS100 is almost identical to that of an AU101 or an AU222, so if you connect this unit as if it is a stereo amplifier, connecting a signal only to the rear inputs and setting the input switch to AUX/4CH, you will have the sound quality of an AU101 or AU222… The decoder uses patented modules for the 4-channel quadrophony effects. I have tried this and although it sounds nice, I would still prefer to use it just as a stereo amplifier.