Putting vintage tubes in the power supply of pre

yes..my pre is a canary 906...i would also like to know which tubes in the LS box are the followers out of the 4..canary is brutal about responding to customers....so..if anyone knows...would be great..the tubes in the power supply are 2 6v6..1 6sl7 and 1 5ar4

Just a suggestion: try a NOS Mullard 5AR4/GZ34 from the Blackburn plant, in the rectifier slot first, and listen for improvements. Then find a NOS TungSol 6SL7GT/VT229 Round Plate(from the 40's). There are a lot of good NOS 6V6 power tubes that will each give you a different flavor in your presentation. ie: If you want a bit more warmth; you might try a pair of Brimars. For a cleaner, more detailed sound; Sylvania or Ken-Rad. RCAs will be somewhere in between. Have fun, and enjoy your music.

Good grief is Rodman on target. Could not have made better suggestions myself.