MEPER....don't know if anyone has answered this to date but I was getting a slight hum when the preamps volumes were turned to max which was bothersome, similar to your situation. Couldn't hear anything at normal preamp levels for playing music but it bothered me anyway. It was independent of turntable being connected, preamp, amp, PS driving the P3, any grounding schema, or opamp. I'm using a Grado Green 3 cartridge (moving iron?). I just tried changing R22 to a ~47R resistor (had them in my stash; bringing the total gain down to ~ 37dB). One channel is now completely silent and the other's hum was decreased dramatically. I'll drop R22 to 40R as soon as my order gets here from Mouser. I'll then do opamp rolling to see which I prefer although the standard 2068 is perfectly fine&dandy.If someone can report less hiss-noise when volumen set to max (MJ-method) by changing a resistor to another brand or value I will be happy to know.
I am also happy that I only hear a bit of hiss-noise when volumen set to max (no hum).
I got my first "aha-experience" when playing a brand new record (Sony music). No groove-noise and not a single "pop". A friend I had for the listening test was also surprised. I have written to the company to know more about the pressing and vinyl composition. Only records of such high quality (or close) can justify all the effort that is put into a high end phono stage like the P3 (my own subjective viewpoint).
@freebee
What opamp(s) are you using? That looks to be a single to dual, SMD to DIP adaptor…? Very interesting!
Why would they?I mean, perhaps single opamps sound better than dual?
Why would they?