Question: what are the best 12ax7 tubes?
Answer: If you wish to use a 5751 in a 12AX7 position to reduce gain we recommend you use the JAN-Philips 5751 tube. JAN-Philips 12AX7WA - If you really want NOS (New Old Stock) tubes, this is one of the best buys out there. The Philips tube is well built and should be long lasting.