Voice manipulation device

Circuit Description

 

Although this kind of voice effect can be obtained by means of some audio computer programs,
a few correspondents required a stand-alone device, featuring microphone input and line or
loudspeaker outputs.
This design fulfills these requirements by means of a variable gain microphone preamplifier built
around IC1A, a variable steep Wien-bridge pass-band filter centered at about 1KHz provided by
IC1B and an audio amplifier chip (IC2) driving the loudspeaker.
This circuit was intended to be powered by a 9V PP3 battery, but any dc power supply in the 6 -
12V range can be used successfully.

        Circuit diagram:

 

Parts List:
P1______________10K Log. Potentiometer
R1,R10__________10K 1/4W Resistors
R2_______________1K 1/4W Resistor
R3______________50K 1/2W Trimmer Cermet or Carbon
R4,R6,R7,R14___100K 1/4W Resistors
R5______________47K 1/4W Resistor
R8______________68K 1/4W Resistor
R9_______________2K2 1/2W Trimmer Cermet or Carbon
R11_____________33K 1/4W Resistor
R12_____________18K 1/4W Resistor
R13_____________15K 1/4W Resistor
C1,C2,C3,C8,C9_100nF 63V Polyester Capacitors
C4______________10μF 25V Electrolytic Capacitor
C5_____________220nF 63V Polyester Capacitor (Optional, see Notes)
C6_______________4n7 63V Polyester Capacitor
C7______________10nF 63V Polyester Capacitor
C10____________220μF 25V Electrolytic Capacitor
IC1___________LM358 Low Power Dual Op-amp
IC2_________TDA7052 Audio power amplifier IC
MIC1__________Miniature electret microphone
SPKR______________8 Ohm Small Loudspeaker
SW1____________DPDT Toggle or Slide Switch
SW2,SW3________SPST Toggle or Slide Switches
J1____________6.3mm or 3mm Mono Jack socket
B1_______________9V PP3 Battery (See Notes)
Clip for PP3 Battery