bought two of these mono boards red pcb and found they were designed wrong. the sync pin is programmed as input (slave operation) and connected to ground. the result is a too low oscillation frequency below 200khz, distortion, excessive current drain.
I changed the programming resistors to set it as master and lifted the sync pin (16) away from ground. luckily this pin is ad the edge of the package so it can be lifted using a pointed tweezer and a soldering iron.
I changed the programming resistors to set it as master and lifted the sync pin (16) away from ground. luckily this pin is ad the edge of the package so it can be lifted using a pointed tweezer and a soldering iron.
Also find the same problem on these boards.
And after removing all components, i also find a wrong capacitor on the EMI CRC snubber (100nF instead of 1nF).
All my ebay amplifier are gone to the bin...
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