Designed by Don Tillman, this guitar pre-amp circuit design is dedicated for people who don”t like op-amps module. This circuit is a discrete JFET pre-amplifier design, use 2N5457 as the main component. It has low noise, low distortion, low feedback, overloads gracefully, is small, etc.
Overall gain is 3db (2X) or so. It uses about 1/2 ma, so a 9V battery will last a long time, you may also use simple regulated power supply with LM7809. It is possible to add a high boost switch in case you like by having it shunt the 2.2k ohm resistor with a 0.05uF cap (or other value; smaller cap = boosts only higher frequencies, as well as the reverse). You may simply placed in a 10uF capacitor across the 2.2k ohm resistor in order to up the gain.? You don”t like pre-amp circuit with op-amps..? then, just try to build this circuit. 🙂
2n5457 Substitute
2N5457, 2N5458JFETs - General PurposeN-Channel - DepletionN-Channel Junction Field Effect Transistors, depletion mode (Type A) designed for audio and switching applications.DRAIN N-Channel for Higher Gain Drain. Designed by Don Tillman, this guitar pre-amp circuit design is dedicated for people who don't like op-amps module. This circuit is a discrete JFET pre-amplifier design, use 2N5457 as the main component. It has low noise, low distortion, low feedback. 2N5457 is a general-purpose N-channel Junction Field Effect Transistor with Drain and Source interchangeable feature. It operates in depletion-mode and requires reverse biasing to turn off. Because depletion types MOSFETs act like a normally closed switch. It has high (AC and DC) input impedance, contrary to other MOSFETs.