All, some clarifications on the Rowland M625 S2 stereo amplifier....
This amp runs in class A/B, not in class D.
It does not contain an LM3886 module.
M625 S2's power supply subsystem contains, among other things,a Power Factor Correction (PFC) rectification module, a Switch Mode Power Supply (SMPS), and a bank of 4-pole capacitors.
Concerning PSU.... There is no PSU inside the M625 amplifier. In the Rowland lingo, PSU is a very specific product. Its full name is Power Storage Unit. PSU is a full chassis external DC power supply created for the Aeris DAC and the Corus preamplifier. PSU is based on ultra-capacitors (a.k.a. supercapacitors). it extracts AC in periodic bursts from the AC mains, stores it as DC in the supercap bank, and delivers a continuous clean DC stream to the component downstream. There is no power storage circuitry inside M625 S2.
More information on the Rowland M625 S2 can be found at:
Jeff Rowland Design Group › model-625-s2
Regards, Guido