Modwright Oppo 105 - Upgrade Power Supply Tubes?

Thanks to the forum & a post by Mrtennis I upgraded the 6sn7 tubes to 1950's RCAs and am most pleased with the change in sound. In my 2 systems with my 2 ears the player went from digital sterile to nice and musical. I am not a fan of the supplied electro-harmonix 6SN7 that is supplied. Thanks again Mrtennis. And here is my question, has anyone found it beneficial to upgrade any of the tubes in the power supply?

Many thanks.
When I had the MW Transporter, Tung Sol NOS 5u4gb was by far the best rectifier tube. It was musical, bloom, detail ... JJ GZ34 for $18 was also excellent and definitely worth a roll.

For reference, I found Mullard GZ34 too warm and rich for my taste.
An extremely musical combination that I am now using (in my Modwright Oppo-95) is a pair of shorty, chrome dome Sylvania 6SN7Gs (w/ black base, green lettering), and an RCA 5R4GY. Very natural sounding across the board, with a great soundstage, and awesome mids. Nothing seems missing in this pairing.

Sorry, I don't agree with the above statement that a 5R4GY is not a good tube match for the Modwright PS9 power supply!
Black Treasure CV181-T was the BEST signal tube in my MW Transporter. I found Sophia 6SN7 to lean for my taste.
Agree completely with mattmiller.  The Philips 5R4GYS has nothing on the low end on the Oppo.  I spent a year diagnosing what was wrong with my system.  I had never even tried the stock tube supplied by Dan.  I was ready to sell everything off in frustration when I made a last ditch effort and changed out this tube. Magic.  Try for yourself and see.