guitar preamplifier

// the ratio of R2 + R3 + P1 to R3 + P1. The input impedance, which, at 1 M, is quite high, is de- fined by R1 as the op-amp has FET inputs. This is a suitable impedance for most guitar pick-ups. A 9 V bat- tery provides the power supply which is converted to a symmetrical + and —4.5 V for the op-amp by means of R4, R5, C3, and C4. Current con- sumption is about 5 mA. The circuit complete with battery can easily be fitted into a small case. If a socket and plug are mounted in the IC1 LF 356 3 447 T16V 84491 gives all the boost that is needed The output signal level provided by many electric guitars is not high enough to overdrive a valve amplifier. This overdriving is an essential part of the final guitar sound. The preamplifier circuit shown here boosts the guitar signal so that the input stage of the guitar amplifier is guaranteed to clip. As an aid to this the gain can be selected between three and eleven times. The layout of the circuit is very simple. A single LF 356 provid...