Working on this Type 3 board.
-Has +-16vDC regulated, and +-105vDC rail.
-No DC on speaker terminals.
-Relays release during power up.
-Idles at 1.9A, but at HIGH input signal pulls about 5A.
-I can observe the square wave oscillation at speaker terminals
-No DC on audio pins of any main opamp
-No protection led
-No failed PS nor output FET.
-Output driver board is like the one attached.
-There is barely any audio at speaker terminals. To me what little audio there is, seems like the amplifier is still muted.
Why would this amp not be passing audio to speaker terminals?
-Has +-16vDC regulated, and +-105vDC rail.
-No DC on speaker terminals.
-Relays release during power up.
-Idles at 1.9A, but at HIGH input signal pulls about 5A.
-I can observe the square wave oscillation at speaker terminals
-No DC on audio pins of any main opamp
-No protection led
-No failed PS nor output FET.
-Output driver board is like the one attached.
-There is barely any audio at speaker terminals. To me what little audio there is, seems like the amplifier is still muted.
Why would this amp not be passing audio to speaker terminals?
Attachments
Do you see significant modulation on the r-r waveform when you drive a strong signal into the amp?
Its working properly including out to clipping. I'll bench press this amp shortly under high load.
There was delay from the time I started to reply to when I finally posted it so the posting looks strange but the question was to determine if there was insufficient signal reaching the drive circuit or was there a break between the output transistors and the speaker terminals. A strong modulation would have indicated a broken connection. Little or no modulation would have leaned towards insufficient signal.