mV rating for Mesa STR440 6L6s...

[KH Guitar Freak]

Does anyone know what the mV rating that is required for biasing to run on Mesa STR440 6L6s???

 

[domct203]

Does anyone know what the mV rating that is required for biasing to run on Mesa STR440 6L6s???

I'm not sure I understand your question. Are you asking what the bias voltage is, or do you want to know the cathode current (mA)?

The bias voltage (measured at pin 5) for 6L6 bias setting is -51 volts. The cathode current (mA) depends on other factors such as plate voltage (B+), amplifier class (A, AB, etc), what color code the tubes are, and of course bias voltage.

GRN STR-440's in my Roadster at 460V B+ measure between 29-31mA (44-47% MPD). Those same tubes in my MKV at 465V B+ measure around 32-33mA (49-50% MPD) in the outer (class AB) sockets and around 43-44mA (65-67%) in the inside (class A) sockets. In contrast the YEL STR-440's in the MKV at the same B+ measure around 25-26mA (37-39% MPD) in the outer sockets (class AB) and around 33-34mA (50-52%MPD) in the inner (class A) sockets.

Dom

 

[KH Guitar Freak]

Does anyone know what the mV rating that is required for biasing to run on Mesa STR440 6L6s???

I'm not sure I understand your question. Are you asking what the bias voltage is, or do you want to know the cathode current (mA)?

The bias voltage (measured at pin 5) for 6L6 bias setting is -51 volts. The cathode current (mA) depends on other factors such as plate voltage (B+), amplifier class (A, AB, etc), what color code the tubes are, and of course bias voltage.

GRN STR-440's in my Roadster at 460V B+ measure between 29-31mA (44-47% MPD). Those same tubes in my MKV at 465V B+ measure around 32-33mA (49-50% MPD) in the outer (class AB) sockets and around 43-44mA (65-67%) in the inside (class A) sockets. In contrast the YEL STR-440's in the MKV at the same B+ measure around 25-26mA (37-39% MPD) in the outer sockets (class AB) and around 33-34mA (50-52%MPD) in the inner (class A) sockets.

Dom

I guess I'm after the bias voltage value, as I would like to install them into my Randall RM100KH. The valve bias test points would require me to adjust the mV values...