@@vacuumtubesandguitars cool. Sovtek 12ax7wa tubes don't seem to be very popular but I've always loved the way they react in all of my amps. They seem to have a neat compression to them that I don't find in other tubes.
the 5751 tube has a gain of 70% whilst the 12ax7 has a gain of 100%... an 12at7 also has a gain of 70%... 12au7 has a gain of 40%... using a 5751 the amp will sound cleaner on the same settings with a little less gain...