Electronic Horn

This is an easy, low cost and easy built circuit of an electronic horn which is designed close to quadruple op-amp IC LM3900 (IC1). IC LM3900 has four independent operational-amplifiers (A1 through A4) having a large output voltage swing. It is able to operate at up to 32V DC. The 1st op-amp (A1) is designed… Read More »

Ultrasonic Motion Detector

This is a ultrasonic motion detector (or movement detector) circuit. The circuit claimed has a high movement sensitivity. Even air moving (hot air rising, wind blowing) will trigger it when the trimpot is set near the most sensitive position. The transmitter sends out a steady ultrasonic tone at 40kHz. At this frequency the wavelength is… Read More »

Electro-Harmonix Small Stone Phaser Guitar Effect

This is the schematic diagram of Electro-Harmonix Small Stone Phaser guitar effect pedal. The Small Stone is somewhat special in applying Operational Transconductance Amplifiers (OTA”s) for phase shift stages rather of opamps with variable resistors. All of the IC”s are house marked EH1048, but could be replaced with CA3094 that is a combination of an… Read More »

Simple Mic Pre-Amp based LM358

Here the simple mic pre-amp circuit design based on single IC LM358. The circuit is very simple, inexpensive and easy to built. This mic pre-amplifier circuit operated with 9V DC voltage, you may use 9V battery for this circuit. Component Parts List: R1, R3, R4 = 10K R2 = 1K R5 = 100K-1M Potensiometer C1… Read More »

A/B Box Switch 2 Inputs 1 Output with Dual Op-Amps

This is a A/B Box switch pedal schematic with two inputs and one output and featured with dual operational amplifier modules. This circuit was designed by Rick Barker. This A/B Box effect was originally designed for switching between different harmonica mics. This A/B Box featured low noise dual preamp for better performance.

VOX Treble Booster Effect

The following scheme diagram is the circuit diagram of VOX treble booster effect. A treble booster is an effects unit used by guitarists to boost volume and especially the high end of their tonal spectrum, and was popular mostly during the 1960s. VOX made a variety of boosters that were meant to be plugged directly… Read More »

Surround Sound Decoder

The following schematic diagram is a small surround sound decoder circuit. You may use this decoder surround sound systems for your home audio system to make the audio system sound more “alive”. Parts List: R1-2-7-8-12-13-18-19-20=47Kohm R3-4-5-6-21-22-34-35=10Kohm R9-10-11-14-15-16-17=15Kohm R=23-24-25-33-36=100ohm R26-27-28-31-32=100Kohm R29-30=5.6Kohm C1-8=47uF 25V C2-7-9-14-23=47nF 100V C3-6=1uF 100V C4-5-10=33pF 100V C11-12-15=10uF 25V C13=82nF C16=18pF 100V C17=100pF mini… Read More »

Tube Distortion Pedal

The following circuit is tube distortion pedal for guitar effect. The circuit designed by Ron Black. Circuit Notes: IC1 : 747 dual op-amp, other ICs may be substitued but pinout will different. You should check the datasheet IC2 : LM340K-12V Voltage Regulator All resistors are 1/2 W Bridge Rectifier – Full wave bridge recitifier, 50… Read More »

Harmonic Sweetener Guitar Effect

This is the one of many guitar effect circuits exist in the world. I have not made this circuit and I also do not know what kind of sound effect harmonic sweeteners, but hopefully this harmonic sweetener guitar effect circuit can help you get a nice effect for your electric guitar. A pair of red… Read More »