I searched in the server sttings, but did'nt find it, where do you find the "PCM setting" knob you are referring to? What is it intended to do when you switch it off?

Holodeck 2: DSP5k2SE+7k2HCSE, DSP33, G68J, 621, DD15, OPPO-203, VW790, ST130G3-120", TSU-9400/RFX-9600, PS4, SB3, Buttkicker-XL (DIY JL 12W7)
In Kitchen: P200Z, T-amp, Equalizer, SB2