sansui amp, on 2 channel mode left speaker drops out

[aifrecords]

on 2 channel mode left speaker drops out for turntable only while if i play cassette deck i hear both speakers on 2 channel mode, anyone know why? when i use synsthesizer simulated mode for turntable i hear all 4 speakers

 

[m1keC]

both left speakers?

 

[par4ken]

on 2 channel mode left speaker drops out for turntable only while if i play cassette deck i hear both speakers on 2 channel mode, anyone know why? when i use synsthesizer simulated mode for turntable i hear all 4 speakers

It is most likely a switch contact. I would open up the unit and look at the switches that control signal switching of the phono section, get in there and spray them with a bit of contact cleaner. DeoXit is even better. Switch contacts cause more problems in vintage equipment than capacitors do.