Sound Effects Generator 2
This circuit uses the Holtek HT2884 IC to produce 8 different sound effects. All sound effects are generated internally by the HT2884 IC. Power is a 3 Volt batt...
Sound Effects Generator
This circuit uses a UM3561 IC to produce four different sound effects. Nothing too complicated here. The IC produces all the sound effects, the output at Pin 3 ...
Audio peak Indicator
This circuit can be used to remotely monitor a loudspeaker, alarm, or audio source for presence of an audio waveform. It can also be directly connected across l...
Audio peak Indicator
This circuit can be used to remotely monitor a loudspeaker, alarm, or audio source for presence of an audio waveform. It can also be directly connected across l...
Audio Analogue Level Meter
Audio levels can be monitored using a small panel meter with this circuit built from discrete components. The circuit has a flat frequency response from about 2...
Audio Tone Control
Based on the classic Baxendall tone control circuit, this provides a maximum cut and boost of around 10dB at 10K and 50Hz. The first BC109C transistor (left ha...
8 Led Audio VU Meter
This circuit uses two quad op-amps to form an eight LED audio level meter. The op-amp used in this particular circuit is the LM324. It is a popular IC and shoul...
Parametric SubWoofer Equaliser
In essence, it uses the same principle as a graphic equaliser, but the simulated inductors are made variable, so the frequency can be swept back and forth. The ...
Feedback Bandpass Filter
These filters are useful for equalisation, analysis and other tasks such as the Sound to Light converter (Project 62) or even a fully functional Vocoder. For th...
Active SubWoofer
The controller is quite (actually very) simple. An input buffer ensures that the input impedance of the source does not affect the integrator performance, and ...
Audio Power Limiter
The gain control element is a Light Dependent Resistor (LDR). These are blessed with a few very useful features for our purposes, one of which is low distortion...
Mike Pads
What got me interested in building these diminutive devices is the S3FM connector assembly made by Switchcraft. The S3FM is simply a 3.5-inch tube fitted with a...
Peak-Reading VU Meters
Peak reading meters, popular in Europe for years, are just now coming into greater favor in America, and for good reason. The main purpose for having a VU meter...
Spectrum Analyzer and Equalizer
The circuit shown in Figure 1 uses only two ICs, and has a bandwidth that is adjustable from more than one octave down to a tenth of an octave. As shown, the fr...
Stereo Synthesizer
There are many ways to create a stereo effect. If you were miking a piano, a string section, or some other large sound source, you`d probably stick up a pair of...
very stable BUG
Is a 100 to 200 metre (100 to 200yds) device having a very stable performance. It can be used as a hand held microphone or left on a shelf to pick up the sounds...
Butterfly Mixer Circuit
If the transmitter stick-potentiometer delivers a voltage about 2 - 3 V, this circuit will be suitable. If you want to avoid using the battery cable (supplying ...
Electronic Canary
Reverse engineered circuit diagram of a commercial Electronic Bird. This one was built into a plastic christmas ornament and runs off a 9V battery. Note that L1...
Underwater microphone
This circuit uses a TBA820 audio 1C to amplify underwater sounds. The microphone must be waterproofed. This project was originally used in a home aquarium to mo...
4 lines Stereo Mixer
With this circuit you can mix four separate audio inputs. Each input will accept high or low impedance microphones, phonograph, tape or aux signals. You can adj...