场效应管音频混合器 (FET Audio Mixer)

场效应管音频混合器 (FET Audio Mixer)

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.

Schematic

Parts

Part
 Total Qty.
 Description
 
R1, R3
 2
 10K Pot
 
R2, R4
 2
 100K 1/4 W Resistor
 
R5
 1
 6.8K 1/4 W Resistor
 
C1, C2, C3
 3
 0.1uF Capacitor
 
Q1
 1
 2N3819 Junction FET
 
MISC
 1
 Wire, Shielded (Metal) Case, Phono Or Other Plug For Output

Notes
1. 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 25 inputs!

2. A shielded case is probably needed to reduce hum and help stop oscillations.

3. The circuit can be powered by a single 9 volt battery.