Hello all. Working on a P8002 board number PC-4708-B.
I replaced all the outputs, gate resistors and source resistors in this amp. The amp powers and idles fine, and will bias. It also produces clean audio on both channels. I did also replace some smd diodes and transistors and various resistors.
My question is about the bias. It draws current sooner in the pot rotation than I'm used to seeing and mv readings across the source resistors vary from .2mv to 1.6mv
Should they all have the same readings or is this normal?
I replaced all the outputs, gate resistors and source resistors in this amp. The amp powers and idles fine, and will bias. It also produces clean audio on both channels. I did also replace some smd diodes and transistors and various resistors.
My question is about the bias. It draws current sooner in the pot rotation than I'm used to seeing and mv readings across the source resistors vary from .2mv to 1.6mv
Should they all have the same readings or is this normal?
The threshold voltage may be lower than the original FETs.
The threshold voltage of the FETs or the source resistor actual value can make a difference between the parallel resistor readings. A better test is to drive the amp to about 10v AC into a dummy load and then measure the voltage across the source resistors. They should read very nearly the same with that test (within a few percent of each other).
The threshold voltage of the FETs or the source resistor actual value can make a difference between the parallel resistor readings. A better test is to drive the amp to about 10v AC into a dummy load and then measure the voltage across the source resistors. They should read very nearly the same with that test (within a few percent of each other).
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