Notice that some of the details are left to the reader's imagination because there are so many ways to use this preamp. For example:
* Mount it on-board the guitar, after the pickup selection switch, volume and tone controls.
* Use a separate preamp on each pickup.
* Mount the preamp on a belt or guitar strap.
* Use it for piezeoelectric pickups for violin, string bass, etc..
* Bypass R2 with a small value capacitor for a treble boost.
* Bypass R2 with a large value electrolytic capacitor for more gain.
* Phantom-power the preamp