For the last while I have been considering putting the volume pot. after the first stage of a 2-stage push-pull MOSFET Class-A amp. An advantage to having the attenuation after the first stage is that the first stage sees more of the signal and might lose less detail. The problem I've been worrying about lately is that running the first stage at full power (about 2W) and then attenuating its output might cause the output to be less linear since the first stage is running at full power and Class-A MOSFET amps are more linear (and thus less distortion) at lowish power. Any suggestions/opinions?
The circuit uses global feedback but would it be a good idea to use local feedback on the first stage as well or would that be redundant?
Are their any errors in circuit? I've caught a few errors in the circuit in that the bias volt divider output should be behind the gate resistor. I plan to breadboard the first stage but I wonder about the power stage since I don't know very much about source-followers and they seem to work in a complex way.
I plan to use resistors between the rails and MOSFETS for the first-stage to set the bias current like the power-stage. Would values of 1 or 2 ohms be suitable?
[IMGDEAD]http://www.bts74.com/AMP/BROCK.GIF[/IMGDEAD]
The circuit uses global feedback but would it be a good idea to use local feedback on the first stage as well or would that be redundant?
Are their any errors in circuit? I've caught a few errors in the circuit in that the bias volt divider output should be behind the gate resistor. I plan to breadboard the first stage but I wonder about the power stage since I don't know very much about source-followers and they seem to work in a complex way.
I plan to use resistors between the rails and MOSFETS for the first-stage to set the bias current like the power-stage. Would values of 1 or 2 ohms be suitable?
[IMGDEAD]http://www.bts74.com/AMP/BROCK.GIF[/IMGDEAD]