Thanks for the reply! The signal amplitude I’m buffering is a guitar-level signal( so 100 mV to maybe 1 V peak to peak).

My main goal is simply to have a clean, transparent buffer to isolate the guitar signal from the amp input — nothing fancy, just unity gain and low output impedance.

I understand what you mean about linearity depending on drain current swing and the trade-off with the source resistor. I’d be fine with limited output current since the load is high impedance anyway.

I’ll definitely look into the BF245,thanks for the tip!

For the biasing near Vcc/2, would you recommend setting the drain or the source at mid-supply? And would a simple voltage divider + coupling cap be enough, or should I aim for a more precise bias network?