6L6 can be substituted by 6N3C tube, provided a very small change to heater voltage.
The heater voltage for 6L6 is 6.6VAC and for the 6N3C is 6.3VAC.
The substitute for 12AX7 is ECC83
Matched pairs of 6L6 or 6N3C should be used at the output stage. Otherwise, some bias adjustments should be done to compensate the gain of the output valves. (R42) is the adjusting resistor for this purpose.
Use good quality valve sockets to avoid distortion. Some sockets may have poor contacts, and should be avoided. Sockets with gold plated contacts are recommended.
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The heater voltage for 6L6 is 6.6VAC and for the 6N3C is 6.3VAC.
The substitute for 12AX7 is ECC83
Matched pairs of 6L6 or 6N3C should be used at the output stage. Otherwise, some bias adjustments should be done to compensate the gain of the output valves. (R42) is the adjusting resistor for this purpose.
Use good quality valve sockets to avoid distortion. Some sockets may have poor contacts, and should be avoided. Sockets with gold plated contacts are recommended.
Pre-amplifier schematic
Push-pull power amplifier schematic
Pin numbers are indicated with one of the 6L6 valve at (top-left) in the circuit.
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Click on the schematics to magnify
Pin numbers are indicated with one of the 6L6 valve at (top-left) in the circuit.
