Hi, I had read recently that Post-Phase Inverter Master Volume (PPIMV) controls within a feedback loop were a bad idea. Having built a few amps that used that configuration, I was surprised. Reviewing a sample schematic, I thought I'd ask the group for their opinion, and hopefully rationale. Here is the schematic, borrowed from Robrob's Blackvibe, with my Frondelli PPIMV: The R20/R10 pair form the feedback circuit, and VR6A/B form the PPIMV. I'm having trouble seeing the badness in this arrangement, since it seems to work for me in real life. Can anyone explain to me where I've gone astray?