Hi KlausST
same think if I don't connect a speaker.
no I didn't make scope in output.
but for test I remove the high voltage powersupply (+60 / 0 / -60)
just I connect the low voltage (+15 / 0 / -15)
so when I rise audio level the limit light.
I changed the AOP name I100A (datasheet CL100-CP2200) but in my audio amplifier have other name (but saùe R111, R112, Q103...) because the sound when enter to I100A it is distored in output and the audio level change from 0 to fixe signal level (when i change volume the input change but output no). when i changed the audio quality is more good and I can change level audio. But I forget something, when I listen to continius BEEP (because I send 440 HZ sinus signal) the audio level rise and fall without I made any change.
for the same audio amplifier the other channel still not working, in first time the other channel have a problem, when no sound in input the output is in 60V. so the amplifier open the relay, light LIMIT and PROTECT, and switch ON fan for high speed, so I changed :
- Q356 (2N3904)
- Q357 (2N3906)
- Q315 (MJE340)
- Q314 (MJE350)
so now the voltage level is 3.9 V (not in zero) but not working when I put sound