30 LED audio frequency analyzer
This analyst is, a sensitive instrument, in the frequency changes and width of a acoustic signal. Thus the brightness of LED that turns on each moment of is ...
Microphone balanced preamplifier
A professional suggestion for those interested in improving sound. The circuit constitutes the part of input mixing console sound from the microphone or source...
Melody Doorbell circuit
In all the houses exist the bells in the door. All want, they have the possibility of being possible to change the intensity, the tone of sound. With this circu...
300HZ - 3KHZ Audio Filter
The human speech apprehend a small area of frequencies, that is extended from 300HZ until 3KHZ. This spectrum is also internationally recognized for the transmi...
3 Way Crossover -24dB
e circuit, is a classic circuit of electronic crossover. Stand in for, the circuits of passive crossover that exist in all loudspeaker three way. The difference...
Wah pedal for Guitar
The right way to do this is with a small extra pc board to accommodate the new components, firmly secured inside the case, and wired carefully and neatly. Unfor...
Guitar Overdrive circuits
Although labelled as distortion, this is a soft clipping device, using germanium diodes. It's a good example of how little you need for a good basic sound. You ...
1,5V Earphones Audio Amplifier
This audio amplifier circuit, connected to 32 Ohm impedance mini-earphones, can detect very remote sounds. Useful for theatre, cinema and lecture goers: every w...
Tone detector / Sound Activated switch
The detector (below) is a bit more complex. It amplifies a microphone and sends the resulting signal to an NE567 tone decoder. The amplifier is half of a 1458 ...
Sound amplitude meter
I made this project as a test to improve a technic to read analog values without analog-to-digital converter. (ADC) I ended with this "sound meter". It may not ...
Voice Recorder and Playback using ISD100A
The ISD1000A is a Direct Analog Storage device which allows you to store 20 seconds worth of voice data on an IC chip which can be play backed anytime. The dat...
Automatic Audio Shutoff
The purpose of this circuit is to automatically turn off any device plugged into its power outlets after a certain period of time. Shutoff is activated by an ab...
Analogue Pitch Shifter
This is two three pole bandpass filters with the HPF Fo about 50Hz and the LPF Fo about 15kHz. This limits the input bandwidth to the phase sequence array, whic...
UHJ Ambisonic Decoder
The decoder is intended to be a reference quality prototype with maximum flexibility for experimental use with different speaker layouts. A new improved version...
Ambisonic Pan-Rotate
LM13700 VCAs are used in a configuration identical to that shown in the Nat Semi data sheet that produces minimal distortion. It is not perfect but then VCAs ne...
Flanger and Echo circuit
This is a 3U rack unit with standard mains power supply. It provides audio routing and speed control for two domestic three-head cassette tape machines such tha...
Ambisonic soundfield type Microphone
A three-dimensional surround sound Ambisonic recording can be captured using a tetrahedrally arranged quartet of cardioid pattern microphone capsules connected ...
Organ Sound Generator
Originally, the prime harmonics were generated with 74HC4046 PLLs which were spot-on accurate but would take some time to reach their final frequencies, especia...
Triple Spring Reverb
This spring reverberation unit comprises three identical main sections each of which contains an Accutronics type 9 spring reverb tank with short, medium and lo...
MOSFET Headphones
This headphone buffer is based on Greg Szekeres' MOSFET Headphone Driver. It is a robust and reliable zero feedback, class A circuit. [Editor: And like the Szek...