Categories: Pre-amplifier

DIY Guitar Transistor Preamp

Here the circuit design for DIY guitar transistor preamp. It consists of a circuit of two transistors and four controls that can be vary the level of the treble, bass, gain, and total salidad circuit (volume). It can be used as buffer at the beginning of a chain of effects. Or combine it with the Marshal Guvernor and a power to put together a cute amplifier.

The circuit working with 9v dc power supply or battery.

Guitar Preamp Components list:

Nonpolar Capacitors

  • 0.01uF
  • 0.1uf
  • 4700pF
  • 0.047pf

Electrolytic Capacitors

  • 1uf x 2
  • 1uf x 2 (Tantalum)


  • 2N5089 (NPN or other) x 2


  • 1M x 2
  • 47k x 2
  • 2.2k x 2
  • 100k x 2
  • 4.7k
  • 22k
  • 1k


  • 250 Kohm linear x 2
  • 250 Kohm log
  • 10 Kohm linear
Amplifier Circuit :