This post isn't about amplification per se, but still pertains to tubes. I have been playing around with tube circuits for an analog synthesizer using the articles at http://www.cgs.synth.net/tube/index.html
The section on beam modulators describes a 6AR8 type tube to produce some interesting audio effects. I found the owners manual for the Metasonix modulator at http://www.metasonix.com/TS21man.doc and it describes the operation of the circuit. What is giving me problems is figuring out how pulse width modulation is done with a dual triode. To me it sounds like an asymmetrical multivibrator with some type of adjustment. I tried doing this by varying one of the grid resistors but the pulse width did not seem to change much. Can anyone shed some light on this?
The section on beam modulators describes a 6AR8 type tube to produce some interesting audio effects. I found the owners manual for the Metasonix modulator at http://www.metasonix.com/TS21man.doc and it describes the operation of the circuit. What is giving me problems is figuring out how pulse width modulation is done with a dual triode. To me it sounds like an asymmetrical multivibrator with some type of adjustment. I tried doing this by varying one of the grid resistors but the pulse width did not seem to change much. Can anyone shed some light on this?