Hi guys, I have this amp on the bench. It is in protect, but I can't find why. There are no shorted outputs or power supply FET's. The 494 pins 1 & 3 have a fluctuating voltage. Pin2 is at 3.7
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Are any of the outputs heating up when the amp is pulsing? Monitor the temperature of all of the heatsink mounted components while checking this.
Only connect ground and remote (no B+) and look at the drive signals on the gates of the FETs. Are the drive signals OK?
Don't have no signal on the gates, or pins 9 and 10 of 494. Don't even have 12v on pin 12 or 5 volts on pin 14 without B+ hooked up
They have been having that feature for 30 years. Its sad if they lost it.
Do you have a current limiter for your 12v supply?
Do you have a current limiter for your 12v supply?
This is a prime amp, it's likely just some chinese type amp.
Do you have a large 2 ohm current limiting resistor or similar? The resistor produces more consistent results.
Do you have a large 2 ohm current limiting resistor or similar? The resistor produces more consistent results.
Maybe. Ideally, something like a 2 ohm, 100w cylindrical wirewound is preferred. Order one the next time you order parts. You can also use it as a moderate power dummy load with fan cooling.
I do have 5 of them at home, will have to bring a couple to leave here at work. Plus I have a couple of 4 ohm 1000w I use for testing a finished amp (dummy load).
Is the gate drive going all of the way back to ground squarely (very nearly perfectly vertical)?