Electronic Stethoscope
Stethoscopes are not only useful for doctors, but home mechanics, exterminators, spying and any number of other uses. Standard stethoscopes provide no amplifica...
Electronic Stethoscope
Stethoscopes are not only useful for doctors, but home mechanics, exterminators, spying and any number of other uses. Standard stethoscopes provide no amplifica...
Audio Test Oscillator
As a piece of test equipment, an audio oscillator has to be considered essential for anyone working in with hi-fi gear. Together with an audio millivoltmeter (a...
Audio Test Oscillator
As a piece of test equipment, an audio oscillator has to be considered essential for anyone working in with hi-fi gear. Together with an audio millivoltmeter (a...
Transistor Organ
This simple circuit can provide hours of enjoyment as you learn tunes, play duets or just make some really weird sounds by pushing all the buttons at once. You ...
Transistor Organ
This simple circuit can provide hours of enjoyment as you learn tunes, play duets or just make some really weird sounds by pushing all the buttons at once. You ...
Stereo Audio Isolator
This circuit is useful for removing ground loop hum on a remote line level audio signal line. It can be used to to connect a computer sound card to a stereo amp...
Pressure Zone Microphone (PZM) Modifications
After attempting to use this reportedly "pretty good" microphone in a variety of situations with some "pretty bad" results, I dissected the power supply and fou...
Tube Screamer to Octave Screamer
I recently prototyped a Tube Screamer type circuit to refresh my memory about the sound of this pedal. I used a borrowed TS-808 and a Pro Reverb in the mid 80s ...
Pocket-Sized MP3 player
The MP3 player is a new kind of portable audio player. It will be shipped simultaneously from many audio makers in the early part of 2000, and will start a new ...
Mini Portable Guitar Amplifier
This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorpor...
The Big-E Stereo Parabolic Microphone
This device is a stereo amplifier for a high sensitivity stereo parabolic microphone. It can be used for listening to distant sounds. The Big-E can be used with...
Audio Spectrum Monitor
This is an evaluation use of a small graphics LCD module. Last summer, SG12232C graphic LCD module has been sold sold for 1500 Yens from Akizuki Denshi and I bo...
Signal Detecting Auto Power-On Unit
How many times have you wished that there was a simple way to turn on that sub-woofer or some other piece of audio equipment, simply by sending it a signal? Th...
MIDI Controller Footpedal
Here`s a simple project that sends continuous or switch controller MIDI messages that correspond to the position of a potentiometer. Given a few parts and a can...
Stereo Width Controllers
Sometimes, for a variety of reasons, it would be nice to vary the width of the `sound stage` when listening to stereo recordings. Although technically this is a...
Guitar Tone Control
This preamplifier was designed as a stand-alone portable unit, useful to control the signals generated by guitar pick-ups, particularly the contact "bug" types ...
Tone Control Circuit
Based on the classic Baxendall tone control circuit, this provides a maximum cut and boost of around 10dB at 10K and 50Hz. As the controls are passive, the last...
Bass-treble tone control circuit
The LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. An additional control i...
Tone Control
This simple tone control can be used in may audio applications. It can be added to amplifers, used as a stand alone control module, or even built into new and e...