Joehernandez509,
The P-3A is the DAC. The P-1A is a digital upconverter and re-clocker that did reduce jitter imposed by the SPDIF cable feeding it. Green/Red lights really depend on the exact function in question and unfortunately I do not have the instructions. As I recall there is a phase invert choice that can result in a red light. There is also a choice regarding having the P-1A upconvert or having the P-3A upconvert. If you choose direct the P-3A should end up with three green lights and a red light would indicate a failure to lock the signal. Really need the instructions because each button was multi-function.
I went to a BAT VK-5D SE CD player when I stopped using the dac.