Tung-Sol 7581A
Spec:
V1 - Brimar 6059/CV4006 (6BR7/CV2135)
V2 - Westinghouse 6FQ7/6CG7
V3/4 - Tung Sol 7581A
V5 - JJ GZ34S
Figured I could use 6L6GC and it's variants in my EL34 valve amplifier after some checks using LTspice. Fitted some Tung sol 7581A to test out. Cathode biasing seems to work nicely. Plates sit at 428V and screens just below at 427V via 43% UL taps. Output transformer is a 6.6K load which appears to be near perfect for the 6L6. Small bonus is the reduced heat output from the lower heater current (0.9A vs 1.5A)
So far, listening, it sounds every bit as good as the other EL34's and their derivatives. I figure the ~20dB of negative feedback is minimizing any audible differences there may be between the various valves I've tried.
Tung-Sol 7581A
Spec:
V1 - Brimar 6059/CV4006 (6BR7/CV2135)
V2 - Westinghouse 6FQ7/6CG7
V3/4 - Tung Sol 7581A
V5 - JJ GZ34S
Figured I could use 6L6GC and it's variants in my EL34 valve amplifier after some checks using LTspice. Fitted some Tung sol 7581A to test out. Cathode biasing seems to work nicely. Plates sit at 428V and screens just below at 427V via 43% UL taps. Output transformer is a 6.6K load which appears to be near perfect for the 6L6. Small bonus is the reduced heat output from the lower heater current (0.9A vs 1.5A)
So far, listening, it sounds every bit as good as the other EL34's and their derivatives. I figure the ~20dB of negative feedback is minimizing any audible differences there may be between the various valves I've tried.