I'm not seeing any problems with a single rail design. The opamp is happy. Time constants could use a little tweeking, but a negative rail won't fix that. JFETs really start to open up when you get above 15V. All I can say is that a single rail design is more tube like, warts and all The subsonic artifacts of a tube amp are often overlooked.
Now I need a chip power amp with 100K input impedance (at least) and a Presence control.
Now I need a chip power amp with 100K input impedance (at least) and a Presence control.