Stereo to Mono Converter Based on FET

High quality portable unit, Suitable for Subwoofer amplifiers, This simple circuit mixes two or more channels into one channel (e.G. Stereo into mono). The circuit can mix as many or as few channels as you like and consume very little power. The aduk-aduk is shown with two inputs, but you can add as many as you want by just duplicating the "input sectionsdanquot; which are clearly visible on the schematic.

Stereo to Mono Converter Based on FET Circuit Diagram:

Stereo to Mono Converter Based on FET Circuit Diagram

Parts:

P1 = 10K-50K Pot

P2 = 10K-50K Pot

R1 = 100K

R2 = 100K

R3 = 6.8K

C1 = 0.1uF-25V

C2 = 0.1uF-25V

C3 = 0.1uF-25V

Q1 = 2N3819 Junction FET

J1 = Audio input sockets

J2 = Audio input sockets

Notes:

  • As many or as few channels as are required can be added to the mixer.
  • Do this by just duplicating the input "sections" which are clearly shown on the schematic.
  • One version of this mixer I saw had 18 inputs!
  • A shielded case is probably needed to reduce hum and help stop oscillations.
  • P1 and P2 are dual gang potentiometer for stereo version.
  • The circuit can be powered by a single 9 volt battery.