carbon comp resistors do not sound that good like carbon/graphite resistors. The mechanism of resistance generation in various materials os totally different. For audio signals, you should look nowhere except carbon film or graphite resistors. For frequencies in magnitude of MHz they produce excessive noise and are not suitable.
Metal film resistors is a real disaster for music. Like plastic caps. These all sound terrible.
Replace ALL metal film resistors in your regulator, I mean everything! Use nice and cheap carbon films and you will see... Regarding the caps, Vitamin Q and russian K40-Y9 are the best. And do not forget to get rid of this crap of metal in R1, it takes half of the sound!
I have experimented with everything I could imagine, regarding DHT heating, I heard better things with your regulator but it did not make me fly. As soon as I replaced the cap and the R1 crap my mind and soul flew away.
Today I plugged my RV258 Telefunken oldies and I have to admit that Rod's circuit drew me inside the performance of these fantastic tubes as I have never felt before.
I have to give Rod my congratulations once again. The performance with graphite rod and Vitamin Q cap makes your soul fly to paradise! Trust me!