Myles - I'm a refuge from the HC amp forum and figured I'd check out your new digs. I have two tube related questions for you.
Background. I have a Rivera K100 head. As backups to the stock preamp tubes which were:
V1 Sovtek 12AX7WB
V2 Sovtek 12ax7wb
v3 Sovtek 12ax7LP
v4 Sovtek 12ax7wb
v5 Sovtek 12ax7lp
I purchased 5 JJ ECC83S.
Because the Sovtek WBs have a pretty crappy reputation, I figured I'd try the JJs in all slots. There was no major improvement to be heard. I love the sound of the amp but I wonder if I'm using it to its full potential.
Question #1. Without putting in expensive NOS preamp tubes, do you have any reccomendations for my amp using the tubes I already have or maybe some other manufacturers such as EH?
Question #2. The stock power tubes are Svetlana EL34's and Rivera has a stamped #7 on the tubes. I was going to purchase some JJ's as backups. Can I purchase tubes from other manufacturers (since I know the rating that rivera uses)that are rated similarly and not have to worry about adjusting the bias on the amp?
Thanks in advance for your advice.