Devileyes
Member
Picked up this ‘untested’ SA-706 in sort of rough shape.
I’ve cleaned everything, blew it out, pots and switches cleaned with D5 and Fader, had to do it a bunch of times to eliminate scratchiness and noise...even had to use D100 on a few pots.
Mostly working now, but having balance and volume issues.
The balance is much louder on the left channel, I would say too loud.
If you have the balance set to center, left channel is louder than right. Shows on meters as well.
If you turn balance all the way to the left there is no change.
If you turn it to the right the left and right channel both decrease in volume, at about 3/4 the way to the right they sound like they are balanced, but you have to turn the volume up quite a bit to get a decent volume.
The volume pot had a clicking point in it at about 3/4 volume, and looks like it was pushed passed its stop at the high end in the past.
I removed it and there was a small ball bearing rolling around in the outer most pot (it’s a double pot)
I was able to get it out of the top. Now it seems to be working fine as far as no more clicking and it stops at its stop easier.
I haven’t taken the pot apart, but by looking inside of the front one...I don’t see a bearing in that one anywhere?
After putting the volume pot back in, the balance issues stays the same.
If I leave the balance knob at 3/4 to the right the amp sounds wonderful. Maybe a bit quiet. I’d like to figure out what’s the problem.
The amp looks to be all original inside, so maybe bad caps? Bad solder joint? I did pull the relay cap off and tried cleaning the contacts, but that changed nothing. I did have to reflow the solder joints on the relay after cleaning though, as it stopped clicking after I cleaned it. But after a reflow it started working again.
I’ve cleaned everything, blew it out, pots and switches cleaned with D5 and Fader, had to do it a bunch of times to eliminate scratchiness and noise...even had to use D100 on a few pots.
Mostly working now, but having balance and volume issues.
The balance is much louder on the left channel, I would say too loud.
If you have the balance set to center, left channel is louder than right. Shows on meters as well.
If you turn balance all the way to the left there is no change.
If you turn it to the right the left and right channel both decrease in volume, at about 3/4 the way to the right they sound like they are balanced, but you have to turn the volume up quite a bit to get a decent volume.
The volume pot had a clicking point in it at about 3/4 volume, and looks like it was pushed passed its stop at the high end in the past.
I removed it and there was a small ball bearing rolling around in the outer most pot (it’s a double pot)
I was able to get it out of the top. Now it seems to be working fine as far as no more clicking and it stops at its stop easier.
I haven’t taken the pot apart, but by looking inside of the front one...I don’t see a bearing in that one anywhere?
After putting the volume pot back in, the balance issues stays the same.
If I leave the balance knob at 3/4 to the right the amp sounds wonderful. Maybe a bit quiet. I’d like to figure out what’s the problem.
The amp looks to be all original inside, so maybe bad caps? Bad solder joint? I did pull the relay cap off and tried cleaning the contacts, but that changed nothing. I did have to reflow the solder joints on the relay after cleaning though, as it stopped clicking after I cleaned it. But after a reflow it started working again.
