Asteroid
Member
I have noticed a very intermittant and slightly strange weak channel problem on my Sansui AU217 amplifier. From what I can gather one channel becomes weak when running from a fairly low level input signal, particularly the phono stage and seems more likely to occur from cold. When running the amplifer on the phono input, with all other devices switched off the right channel becomes rather weak - however if I switch on another device (tuner, cdp) ,while keeping the input switch on phono, the weak channel becomes good. But I have also noticed the right channel become weak when tuning a very weak low level (mono) station with the tuner, it seems much less susceptible from the tuner however. The amplifier otherwise works flawlessly off the cdp, and tuner on a normal station. The phono input also works fine 95% of the time.
As yet I have not cleaned the pots and switches, but it has seen moderate use in the 8 years I've owned it so they all work quite okay. Working the volume knob, tape monitor and source switch do not appear to make a difference.
What type of problem am I likely to be chasing, a poor connection in the pots etc, a weak transistor or other circuitry problem? Pre or power stage?
I'd greatly appreciate some guidance so I know where to start.
Thanks guys.
As yet I have not cleaned the pots and switches, but it has seen moderate use in the 8 years I've owned it so they all work quite okay. Working the volume knob, tape monitor and source switch do not appear to make a difference.
What type of problem am I likely to be chasing, a poor connection in the pots etc, a weak transistor or other circuitry problem? Pre or power stage?
I'd greatly appreciate some guidance so I know where to start.
Thanks guys.
