Guitar Pre-Amplifier

A photo of the Revision-A preamp is shown below. You'll see that there are two dual opamps, but the schematic only shows one. This is the main part of the Rev-A update - the output section now has gain (which is easily selected), and a better buffered low output impedance. The remainder of the circuit is unchanged. Full details of the new version are available on the secure site for those who purchase the PCBs.


Download this image.

The preamp circuit is shown in Figure 1, and has a few interesting characteristics that separate it from the "normal" - assuming that there is such a thing. This is simple but elegant design, that provides excellent tonal range. The gain structure is designed to provide a huge amount of gain, which is ideal for those guitarists who like to get that fully distorted "fat" sound.

However, with a couple of simple changes, the preamp can be tamed to suit just about any style of playing. Likewise, the tone controls as shown have sufficient range to cover almost anything from an electrified violin to a bass guitar - The response can be limited if you wish (by experimenting with the tone control capacitor values), but I suggest that you try it "as is" before making any changes.





Download this schematic diagram.



semiconductor datasheet component. (PDF Format)

1. TL072
2. BC549