Mono To Stereo Synthesizer

This circuit attempts to liven up mono sound sources by simulating a
stereo signal. It does this by shifting certain frequencies between left
and right to fool the ear. It can often produce a passable mock stereo
sound to bring some depth to otherwise flat recordings. Of course,
there is no way to produce real stereo sound from a purely mono source
unless the synthesizer had a way to tell which direction the original
sound came from, but an illusion is generally enough for all but the
hard core audiophile.


This is the schematic of the Stereo Synthesizer


Total Qty.
R1 1 4.7K 1/4W Resistor
R2 1 10K 1/4W Resistor
R3 1 12K 1/4W Resistor
R4, R6 2 22K 1/4W Resistor
R5 1 11.K 1% 1/4W Resistor
R7 1 16K 1/4W Resistor
R8 1 100K 1/4W Resistor
R9 1 24K 1/4W Resistor
R10 1 18K 1/4W Resistor
C1 1 0.1uF Ceramic Disc Capacitor
C2, C3 2 0.47uF Ceramic Disc Capacitor
C4, C5, C7 3 0.01uF Ceramic Disc Capacitor
C6 1 0.013uF Ceramic Disc Capacitor
C8, C9 2 4.7uF 25V Electrolytic Capacitor
C10 1 0.22uF Capacitor
C11 1 47uF 25V Electrolytic Capacitor
C12 1 100uF 25V Electrolytic Capacitor
D1 1 LED (Red, Green or Orange)
U1 1 TBA3810 (442-794)
S1 1 SPDT Switch
S2 1 SPST Switch
J1, J2, J3 3 RCA Jack Other suitable jack
MISC 1 PC Board, Wire, Case, Holder for D1, Socket for U1


  1. This circuit was sent in by oRbEq (email address unavailable).
  2. S2 controls power to the circuit. Switching S1 to ground
    bypasses the circuit and outputs mono sound to both output jacks.
    Setting S1 to R1 enables the synthesized stereo sound at the outputs.
  3. The circuit draws very little current and can thus be powered
    by most any well filtered 9V-12V source (including a standard 9V radio

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