Hello guys, Im working on a small headamp project which will have mosfet (IRF520) classic source follower as the output stage. Currently Im using 200ohm resistor, class A, idle current about 150mA. Currently Im using 60ohm resistor. My question is this: I have lying around some chokes currently intended for tube amplifiers power supplies. Thy are rated at 5H 200ma dc current and they have DC resistance of 60 ohms. Can I use this choke instead of the resistor? The voltage will be the same. Will this ramp up the voltage headroom and efficiency and increase dynamics? Anybody used this with MOSFETs? Thanks. Im pinning my current schematic. (edit, in reality, 20k multi turn trimmer is used to set the bias instead of the 3k7-9k resistors)
May I suggest a basic CCS approach?
LINK: https://sound-au.com/project83.htm
The circuit will not provide any voltage gain but it will provide ample current gain, I have used this circuit and has never failed me, easy and reliable.
I would recommend zener protection on the bottom FET as well.
You can drive this with the VAS of your choice, in or out of its feedback loop. just watch out for input gate capacitance and the 4/5v drop for the FETs.
LINK: https://sound-au.com/project83.htm
The circuit will not provide any voltage gain but it will provide ample current gain, I have used this circuit and has never failed me, easy and reliable.
I would recommend zener protection on the bottom FET as well.
You can drive this with the VAS of your choice, in or out of its feedback loop. just watch out for input gate capacitance and the 4/5v drop for the FETs.