Thanks John, I'll look into it!
The reason I ask for these regulators is that people report the Hypex amplifier modules with them fitted sound quite a bit better, and all those regulators do is provide power to the op amp before the actual amplifier. So I imagine this would be an easy was to improve the performance in a lot of gear by simply switching out standard regulators for the HxR ones, since many, especially the modern op amps seem to be quite sensitive to the quality of the power they get. But the regulators don't seem to be availible seperately...
The Hypex class D amp modules spec out very well without redesign effort. http://www.hypex.nl/docs/papers/ncore%20wp.pdf
Looking at a recent white paper by Bruno, shows 2 tone IMD down >100 dB which strikes me as quite good.
My PS design was kind of an exercise in excess, not really a practical design to address a real problem.
PSRR of decent modern opamps, used at modest gains is quite good, so even a simple 3 terminal regulator should perform adequately
Before you do a ton of work, try hanging some large caps on the existing regulators and see if you can measure a difference.
The relationship between PS noise and audio path is defined in the spec sheet while you need to factor in noise gain of specific gain blocks to factor that PSRR by, since it is referenced to opamp inputs, not outputs.