/diy/ - Do It Yourself

Jfet or other high impepedance preamp. Jfets are getting hard to find though. J201 is almost gone, MPF102 is getting rare. You could use a TL072 or OPA2134 opamp.
Then you need an amplifier. LM386 is the standard first project that fits in an altoids tin and provides .5 watt from a 9V battery. Googe "noisy cricket" or "little gem" schematic.
Also check out https://www.sound-au.com/p-cat.htm#mus , he's got the best audio projects on the net. Check out his preamp shematics for the guitar amps.

How is this layout? Inputs too close to power rails? This is just the top side.