Anyone got pics or a schematic for or similar to this amp?
I got this one in, cust had it at another tech; one shorted output and 15v regulator with burnt power supply, there seems to be some parts missing around the sg3525 and a resistor mod to pin 10 from the TL072, R81, R82, R83 (burnt) all read open.
Thus far I’ve removed the shorted output, and replaced the tip42 regulator. I’ve soldered in one PS Fet per bank and jumpered the sg3525 to start pulsing. The amplifier powers up ok and passes clean audio on both channels.
I believe the missing and burnt components are part of the regulation circuit for this amp. The rails measure +/-70vdc at 11.2vdc input, if I increase the input voltage it goes up. The rail caps are 100v.
I got this one in, cust had it at another tech; one shorted output and 15v regulator with burnt power supply, there seems to be some parts missing around the sg3525 and a resistor mod to pin 10 from the TL072, R81, R82, R83 (burnt) all read open.
Thus far I’ve removed the shorted output, and replaced the tip42 regulator. I’ve soldered in one PS Fet per bank and jumpered the sg3525 to start pulsing. The amplifier powers up ok and passes clean audio on both channels.
I believe the missing and burnt components are part of the regulation circuit for this amp. The rails measure +/-70vdc at 11.2vdc input, if I increase the input voltage it goes up. The rail caps are 100v.
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It's possible that the regulation acts more like a limiter or you're not supplying enough voltage for it to go into regulation.
The regulation typically feeds into the error amp via two relatively high value resistors. I don't have anything on the VGA supplies because they're just shown as one block (no circuit).
The regulation typically feeds into the error amp via two relatively high value resistors. I don't have anything on the VGA supplies because they're just shown as one block (no circuit).