A friend has a Niles ZR-4630 that he wants made into independent amplifiers. There are six stereo amplifiers based on the LM3886 IC. I have been reverse engineering it. By default the mute is "on" for the amplifier modules. Here are some pictures of the guts.
This shows the amplifier modules and the power transformer. We could not get the power on by the on off switch so we hot wired power to the transformer.
This is another view of the transformer and amplifiers.
This is a view of the back side of the guts.
So far I have been able to confirm the pins of the amplifiers. There is more to come.