Good day gents,
I got this SS AR1.2500D (similar to SLA-1500), completely rebuilt, PS, outputs and driver card.
The amplifier currently passes distorted audio. with my 8ohm dummy load hooked up it passes clean audio up to around 6/7vrms, after this it gets distorted.
I've attached the waveforms for both high side and low side output FETs (no audio into amplifier). I've tried numerous LC filter values/combinations to no avail.
I'm seeing the high side has a notch in it. will this be the contributor to the noise/distortion?
Anyone got a remedy for this?
I got this SS AR1.2500D (similar to SLA-1500), completely rebuilt, PS, outputs and driver card.
The amplifier currently passes distorted audio. with my 8ohm dummy load hooked up it passes clean audio up to around 6/7vrms, after this it gets distorted.
I've attached the waveforms for both high side and low side output FETs (no audio into amplifier). I've tried numerous LC filter values/combinations to no avail.
I'm seeing the high side has a notch in it. will this be the contributor to the noise/distortion?
Anyone got a remedy for this?
Attachments
There may be 2 problems.
The top of the high-side drive shouldn't have (I wouldn't expect) the drop 1/2 way across the flat of the waveform.
See if you can find out where that's coming into the drive signal.
Connect a 0.1uf cap directly across your scope probes and a 10k resistor in series with the positive lead and post the waveform taken directly across the speaker terminals.
The top of the high-side drive shouldn't have (I wouldn't expect) the drop 1/2 way across the flat of the waveform.
See if you can find out where that's coming into the drive signal.
Connect a 0.1uf cap directly across your scope probes and a 10k resistor in series with the positive lead and post the waveform taken directly across the speaker terminals.
I didn't try the cap/resistor as you suggested. You had me thinking the driver card was outputting clean square waves and somehow it was getting skewed on its way to the high side gate.
I took a closer look at the drive components, on my second attempt I found one of the driver transistors (2X) leaking. I replaced both (2T and 2X) and I have a clean square wave at the gates.
The amplifier now passes clean audio. onto the turn on/pop I get.
Thanks for the assistance Perry.
I took a closer look at the drive components, on my second attempt I found one of the driver transistors (2X) leaking. I replaced both (2T and 2X) and I have a clean square wave at the gates.
The amplifier now passes clean audio. onto the turn on/pop I get.
Thanks for the assistance Perry.