I would add identical resistors across C19 and C20 in the virtual ground power supply to try to keep the +/- voltages equal. Differences in capacitor ESRs could affect the balance.
I made this circuit but when input is increasing above 300mv rms then output is clipping (skipping voltage divider at input ) and I have connected 22k pot (vol) at J1 ,,, when I am turning it full (full volume) its making ~150khz noise of around 100mv (no signal at input).
