I received this amp with blown output filter capacitors. I checked the outputs for rail to rail oscillation and it’s present at 120volts. I replaced the capacitors and they blew again. Before the caps blew I out a 40hz signal through the amp and it looked great at the speaker terminals on my oscilloscope. They are 22uf 250volt caps.
Did you have a load on the amp when you checked it with a scope?
Where did you get the caps?
Film caps or electrolytic caps?
An intermittently shorted inductor can do this.
Where did you get the caps?
Film caps or electrolytic caps?
An intermittently shorted inductor can do this.
Are the caps directly across the output or are they in reverse-series pairs across the output?
Bipolar caps or polarized?
Bipolar caps or polarized?
Positive of capacitor goes on the positive of the speaker terminal. Negative of capacitor feeds into the secondary side of power supply transformers.
Didn’t have the amp infront of me when I made post 7 got home looked at the amp and made post 8.
Do you still have the original caps?
If one terminal goes to the output and the other to the secondary ground, you need bipolar capacitors.
I'm assuming that this amp swings the output signal positive and negative with respect to the secondary ground.
If one terminal goes to the output and the other to the secondary ground, you need bipolar capacitors.
I'm assuming that this amp swings the output signal positive and negative with respect to the secondary ground.
Ok, that was my mistake I put the wrong caps in not paying attention. What would make the original bipolar caps explode?
You don't know if it is, yet. You'll have to power it up (caps in the circuit) and push/pull/twist the inductor to see if it ever passes significant high frequency noise to the output or causes a significant increase in idle current.