Mosfet boost as a unity gain buffer question

[Xavier]

What resistor value must I use instead of the gain pot , if I want to use it as a unity gain buffer?

[brett]

Hi
Most of us use JFET buffers rather than the fiddlier-to-bias MOSFETs.
If you really want a MOSFET buffer, you can take the output from the Drain and make the ratio of the Drain to Source resistor 1:1.  Same thing for JFETs and BJTs (in which case it's the collector and emitter resistors).
Alternatively, you can take the output from the Source (for a source-follower, or emitter for an emitter-follower), and connect the Darin (or collector) to the Vsupply.
But heck, all this has been explained in previous posts, so have a search and you'll find the schematics, etc

[Seljer]

se the gain pot so its unity gain => measure the resistance on the pot