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.

Schematic

Parts

Part Total Qty. Description Substitutions 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

Notes

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 battery).