The thing about a source follower is that it has an asymmetrical output impedance. The FET pulls the output up with a relatively low impedance, but the only thing pulling the output down is the 10K source resistor. Depending on the values for the output level controls and the loads on their wipers, driving 2 or 3 outputs with one FET could lead to an output waveform that changes shape when the pots are adjusted. For this reason, if you are going to use FETs, stay with one per output.
personally, I would put more effort into finding an appropriate opamp, one with acceptable bandwidth and distortion, and a static current under 500 uA.
ak
personally, I would put more effort into finding an appropriate opamp, one with acceptable bandwidth and distortion, and a static current under 500 uA.
ak