Following The Freaking Heater
12AX7/ECC83 Heater Cathode Voltage with a Cathode Follower SAY WHAT? In my Marshall DSL15c, I love the tone and responsiveness of the Tung-Sol 12AX7 pre-amp tubes, coupled with the singing quality of the JJ 6V6s power tubes. Recently, after replacing the pre-amp tubes, a pre-amp tube burned out after a couple of months, and it was in the middle of a gig. OUCH! The high pitch squealing was horrible. So, I did some research. Good old fashioned research, read, read, read, read, and read some more. Eventually, I figured out that the tube was probably the V3 pre-amp tube. You see, the V3 tube in the pre-amp section of the DSL15C has a cathode follower in the circuit. As a test, I pulled the V3 tube out and dropped in a JJ ECC83 that I had laying around. I rehearsed with my band for over an hour and there was no squealing or other weird noises. Conclusion: it was definitely the V3 tube that died. OKAY, But What Does a Cathode Follower Have to Do With It? Appar