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Baby Marshall Amplifier:
(schematic added 10/06) |
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Balanced Low Noise Microphone Preamp: very low noise, close to
oretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks (added 8/03) |
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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 input allows loudness
compensation to be simply effected. Four control inputs provide control of bass, treble, balance and volume functions through application of DC voltages from a remote control system or,
alternatively, from four potentiometers which may be biased from a Zener regulated supply provided on circuit. Each tone response is defined by a single capacitor chosen to give
desired characteristic.….. (added 10/05) |
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Battery Powered Electret Microphone: Note:
scroll down to this this circuit. This circuit can be used with normal tape recorders and sound cards which usually are designed for dynamic microphones. When you build this circuit
inside microphone case (or to small external box) you can make yourself an universal microphone out of an electret capsule. (added 11/05) |
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Biasing and Decoupling Op Amps in Single
Supply Applications: AN-581 Analog Devices Application Notes (app note added 2/06) |
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Bidirectional 2.4 GHz One Watt Amplifier:
(circuit / schematic added 6/03) |
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Bidirectional 900MHz One Watt Amplifier qsl:
(circuit / schematic added 6/03) |
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Bidirectional 900MHz One Watt Amplifier: This
device is a stereo amplifier for a high sensitivity stereo parabolic microphone. It can be used for listening to distant sounds. Typical parabolic microphones are monophonic, this unit has a
stereo audio path that helps produce more realistic sounding audio. The Big-E can be used with headphones or as an audio source for a stereo tape recorder or a PC sound card. This circuit also
works nicely as a remote stereo audio receiver for accompanying a video surveillance system. It is capable of operating on end of a four wire shielded cable that is more than 100 feet
long. For remote operation, a set of inexpensive amplified PC speakers can be connected to outputs for monitoring sound.... (added 10/05) |
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Binaural Mics: (electronic schematic added 8/02) |
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Boost 33V to 5V with Tiny Audio Amplifier: 09/05/02 EDN
Design Ideas / (added 12/04) This charge-pump circuit quietly converts a 3.3V source to 5V at 500 mA (figures 1 and 2). National's (www.national.com) LM4871LD power amplifier
makes this design idea both possible and practical, thanks to its low output resistance, low cost, compact size, and high dissipation capability. Its output resistance has an average value of
0.... |
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Boundary Layer Dish Microphone: ideas for a
directional microphone assembly (added 4/02) |
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Cellular Phone calling Detector: (electronic
design added 6/07) |
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Cheap DSP Experiments: Digital signal processing
experiments with only a cheap 8bit microcontroller. This project experiments on Delay, Echo, Pitch Conversion, Filter and etc. (added 10/05) |
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Circuit Combines Power Supply and Audio Amplifier:
12/20/01 EDN-Design Ideas / (added 10/03) The circuit in Figure 1 can help if you must transfer dc power and audio over a pair of copper wires. One application for such a circuit is a low-cost
door-opening system with speech input. The circuit uses only one IC, the well-known LM317, a low-cost power-supply regulator. Using this chip, you ..... |
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Class A//A-B 100W Amplifier: A Class A //
Class AB amplifier rated 100 Watts when driving a 4 ohm loudspeaker. (added 10/05) |
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Class-A//AB Amplifier 100W 4ohm: (electronic
design added 6/07) |
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Class-D Audio Amplifier ICs: MicroNote 1503 from Microsem (app
note added 3/06) |
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CMOS IC Audio Oscillator: (electronic
schematic / circuit added 2/07) |
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CMOS Multiplying DACs and Op Amps
Combine to Build Programmable Gain Amplifier, AN-320A: AN-320A Analog Devices Application Notes (app note added 2/06) |
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CMOS Multiplying DACs and Op Amps
Combine to Build Programmable Gain Amplifier, Part 1: AN-320B Analog Devices Application Notes (app note added 2/06) |
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Computer Microphone zen22142: adapting
electret microphone to soundcards with dynamic microphone inputs (added 5/02) |
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Computer Microphone: (electronic
circuit added 4/05) |
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Computer Microphone: (electronic design
added 6/07) |
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Condenser
MIC Audio Amplifier: (electronic Circuit / Schematic added 10/04) |
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Condenser
Microphone Hookup: (circuit added 7/02) |
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Crest Audio LT Series LT100 LT1500 and LT2000
SchematIC Set: A commercial Class D Amplifier, complete schematics in PDF format. (added 4/02) |
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Current Feedback Amp: The amplifier shown here was previously incorrectly
referred to as 'El-Cheapo'. Thanks to a reader who had a copy of the original 1964 article, it was immediately obvious that my recollection was flawed in the extreme…. (circuit /
schematic added 6/03) |
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Death of Zen Doz a New Class a Power Amp: An ultra simple, high
performance Class-A power amp. Revision-A boards now shipping (circuit / schematic added 6/03) |
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Death of Zen Preamp: "Minimalist" preamp, designed to
suit the DoZ (or any other) power amplifier (schematic added 6/07) |
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Digital Nulling of Precision Op Amps: AB-3
Analog Devices Application Notes (app note added 2/06) |
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Digital Volume Control:
This circuit could be used for replacing your manual volume control in a stereo amplifier. In this circuit, push-to-on switch S1 controls the forward (volume increase) operation of both
channels while a similar switch S2 controls reverse (volume decrease) operation of both channels. A readily available IC from Dallas semiconductor, DS1669 is used here.…. (added
10/05) |
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Digital Volume Control: Very simple
digital volume, contrast, brightness, or dimmer control (circuit added 8/06) |
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DN0001 - MP7720 - Using Split Supplies:
Monolithic Power Systems, Inc Design Note (added 3/06) |
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Dual JT-MB-C Microphone Combining Circuit: AS053 Jenson
Transformer Application Note (app note 6/07) |
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Dual Microphones Separate Voice from Noise:
06/23/94 EDN-Design Ideas / (added 4/02) The circuit in Fig 1 uses a pair of microphones to extract a voice from a noisy background. You must mount electret microphones X1 and X2 on the left
and right sides of the user's chest. Sound sources not equidistant from the microphones experience a phase shift. Because sound travels at 1120 ft/sec, the maximum phase shift for this
design's mounting scheme is about 0.5 msec. This phase shift corresponds to a 90 degrees phase shift at about 1000 Hz. Thus, all sounds in the vocal frequency range, except the user's voice,
tend to cancel.... |
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Dynamic Microphone Amplifier:
(circuit / schematic added 6/03) |
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Dynamic Microphone to Electret
Microphone Input: (electronic schematic added 8/02) |
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ECM MIC PreAmplifier: (schematic added
9/02) |
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Electret Microphone Connection: how to
connect electret microphone (added 4/02) |
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Electret Microphone Powering:
(electronic schematic added 8/02) |
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ESP SIM Sound Impairment Monitor: a method of determining just how
much your amplifier modifies the original signal (added 4/02) |
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FET Audio Mixer: (electronic schematic /
circuit added 2/05) |
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Grounding for Low-and-High-Frequency
Circuits: AN-345 Analog Devices Application Notes (app note added 2/06) Know Your Ground and Signal Paths for Effective Designs. Current Flow Seeks Path of Least Impedance-Not
Just Resistance.... |
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Guitar Amplifier 10 Watt: Old-Style ultra-compact
Combo2-inputs-Overdrive-Treble-enhancement (added 9/04) |
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Guitar Amplifier: (electronic schematic /
circuit added 2/05) |
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Guitar Reverb Effect Version 2: (electronic
schematic / circuit added 2/05) |
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Guitar Reverb Pedal: (electronic schematic /
circuit added 2/05) |
