Sansui AU-7700 Speaker pop when Relay clicks

[petehall347]

is it both channels ?

 

[petehall347]

try switching the speakers off then power on and count 2 seconds after relay clicks before switching speakers on . see if it pops .

 

[micaiahm]

is it both channels ?

Yes.

 

[micaiahm]

try switching the speakers off then power on and count 2 seconds after relay clicks before switching speakers on . see if it pops .

Speakers off. Power on. Relay engage. Speakers on to A. No pop.

 

[petehall347]

looking like the timing cap needs upping some more to give 6 seconds . which isnt out of line with many manuals that state several seconds .
the only other thing i can think of is try another relay drive transistor with higher vbe . so it will need more voltage to turn on . you could try and monitor its base voltage now and see what the voltage is when the relay clicks in .

 

[micaiahm]

looking like the timing cap needs upping some more to give 6 seconds . which isnt out of line with many manuals that state several seconds .
the only other thing i can think of is try another relay drive transistor with higher vbe . so it will need more voltage to turn on . you could try and monitor its base voltage now and see what the voltage is when the relay clicks in .

So I put in a 1200uf 16v cap, had it laying around, and it made the difference. It is about a 6sec timing now. No more speaker pop.

Thanks for all the help. Now that I have tunes again, back to the 1280.

 

[petehall347]

nice one .

 

[pete_mac]

Good stuff! Well done.