Misc audio (also see Music, Amplifiers, Preamp)

· Pink noise generator

· A Schottky-based Saw-to-Tri converter

· Saw to triangle converter

· Improved saw to triangle converter

· Voltage controllable LFO

· White noise generator

· Electronic siren

· Two-tone siren

· Underwater microphone

· Code practice oscillator

· Noise generator

· Electronic whistle

· Low Frequency Sinewave Generators

· Horror movies sound effects

· Sound amplifier

· Temperature sensitive oscillator

· Twin-T Audio Sine Wave Oscillator

· 1.5V Audio Amplifier

· Low Power Op-Amp - Audio Amp (Intercom)

· 555 Tone Generator (8 Ohm Speaker)

· 3 Transistor Audio Amp (50 milliwatt)

· Low Frequency Sinewave Generator

· Automatic Charger for Battery Operated Hi-Fi Preamps

· Audio level indicator

· Room noise detector

· Amplifier timer

· Bell ring generator

· Amplified ear

· Precision audio millivoltmeter

· Six-channel Mixer and Amplifier

· Audio Signal Source

· Analog VU meter

· Voltage controlled amplifier

· Audio graphic equaliser

· Intercom preamp

· FET audio mixer

· Microphone mixer

· Tone control

· Digital volume control

· Sound level meter

· CMOS IC audio oscillator

· Ultrasound detector

· Three band Active Tone Control

· Automatic gain control (AGC) circuits

· Audio frequency meter

· Bull Horn

· Sound Mixer/Amplifier

· Very loud beeper (PDF)

· Digital noise generator (PDF)

· Tone display system

· Tube amplifier

· Condenser microphone hookup

· Phase shifter

· Paradoxical Sound Syntheizer

· Various tube crossover circuits

· Bias circuits

· Audio line isolator

· Dynamic microphone to electret microphone input

· Line level signal to microphone input adapter

· Simple two line output combiner

· Electret microphone powering circuits

· Use amplifier phono input as line level input

· Speaker signals to line level inputs

· Spring reverb unit

· Sine wave generator

· Simple amplifier

· 3-Band equalizer

· 6-Input mixer

· Doorphone intercom

· Stereo line driver

· Audio notch filer

· Peak reading audio level meter

· Tone control

· Speaker Microphone Circuit

· Electronic canary

· Electronic siren

· Microphone phantom power supply

· NHT subwoofer amp

· Voltage Controlled Mixer w/Modulator

· Dual Voltage Controlled Oscillator w/Modulator

· Dual Voltage Controlled Filter w/Modulator

· Stereo Ducker

· MS Stereo Decoder

· MS Stereo Microphone

· RIAA Equalized Stereo Phono Preamp

· Tube active crossover

· Improved PL tone decoder

· Magnetic cartridge amplifier

· LM358 preamp

· Sound detector

· Tone detector

· Tone generator

· Warbler

· Fender Champ Replica

· Keyboard scanned 8-tone generator

· Audio test station

· Audio tone VU meter

· Pink noise generator

· Voltage Controlled Panner

· Low Noise Microphone Preamplifier

· Bridging Adapter For Power Amplifiers

· Simple Surround Sound Decoder

· Simplest Ever Amplifier Bridging

· Stereo Width Controllers

· Power Amplifier Clipping Indicator

· Phono Preamps For All

· Digital Delay Unit For Surround Sound

· Parametric And Sub-Woofer Equaliser

· High Quality Sound Mixer

· Loudspeaker Protection and Muting

· Direct Injection Box for Recording & PA Systems

· Minimalist Discrete Hi-Fi Preamp

· Signal Detecting Auto Power-On Unit

· Load Sensing Automatic Switch

· Amplifier thermal protection

· Active Sub-Woofer and Controller

· Balanced Line Driver & Receiver

· VU And PPM Audio Metering

· Variable Amplifier Impedance

· Linkwitz Cosine Burst Generator

· Low Noise Balanced Microphone Preamp

· Fast Audio Peak Limiter

· Subwoofer Equaliser

· 110 dB beeper - 74C14

· Audio output level meter

· Surround Sound Decoder Mk2

· Stereo compressor

· Audio mixer