Audio (Musik, Amplifier, Preamp)

• "Anti-RIAA" Equalizer for Line to Mag Phono Converter (PDF)
• 1 Watt audio amp using a TDA7052
• 12 watt audio amplifier with tone using TDA1020
• 3 Channel Spectrum Analyzer
• -30dBm to +30dBm Audio Level Meter
• 3-Band audio graphic equalizer
• 4 channel audio selector
• 5 watt audio amplifier using TDA1010
• 6-Input mixer
• Acoustic Simulator for Headphone Amplifiers
• Active Sub-Woofer and Controller
• Actvie speaker based on a dual op-amp (LM833) and TDA2030 power amp
• Additional RFI protection for line input circuit diagram (PDF)
• Amplifier thermal protection
• An Audio Limiter for NBFM use
• An Audio-Noise-Based Voting Circuit
• Analog Synth Keyboard Schematic
• Assortment of Siren Circuits
• Audio DAC3 (SPDIF->Analog Audio)
• Audio Detector Circuit
• Audio graphic equaliser
• Audio Indicator - monitor a loudspeaker, alarm, or audio source for presence of an audio waveform
• Audio line isolator
• Audio mixer (ASCII circuit diagram)
• Audio Signal Source
• Audio Spectrum Analyzer and Equalizer Designs
• Audio Speech Processor
• Audio VU Meter based on pair of LM324 quad opamps
• Automatic Charger for Battery Operated Hi-Fi Preamps
• Automatic loudness control
• Balanced Line Driver & Receiver
• Base / treble control circuit using LM1036N
• Bass booster using a TL702 opamp
• Bass EQ pre-amp correction for high impedance ceramic crystal pickup
• Beat Tracking Strobe
• Better Volume (and Balance) control circuit diagrams
• Big Ben sound effects generator
• Bridging Adapter For Audio Power Amplifiers
• Bridging Adapter For Power Amplifiers
• Build a Tape Linearizer and a Distortion Analyzer
• Cicuit diagram for super long range microphone for use with a shotgun microphone or parabolic dish
• Clack Clack Electronic Bell
• CMOS IC 1 kHz Audio Oscillator
• Condenser microphone hookup
• Cuckoo sound generator
• Cuckoo sound Generator
• DC Fault Protection Circuit for Audio Amplifiers
• Defeating SCMS on DAY recorders using a Sony CXD2601 chip
• Digital Delay Unit For Surround Sound
• Digital noise generator (PDF)
• Digital volume control
• Digital volume control
• Digital Volume Control based around CD4067 CMOS chips
• Digital Volume Control using DS1669 Digital Pot IC
• Digital Volume Control using DS1669
• Direct Injection Box for Recording & PA Systems
• Doorphone intercom
• Dual Voltage Controlled Oscillator w/Modulator
• Dynamic microphone to electret microphone input
• Electret microphone powering circuits
• Electronic attenuator
• Electronic Canary
• Electronic canary sound effects
• Electronic siren
• Envelope generator ADSR
• Fast Audio Peak Limiter
• FET Audio Mixer
• FET audio mixer
• Guitar Reverb Effect Version 2
• High CMRR Balanced Interface for Crystal 18 or 20 Bit A/D Converters (PDF)
• High Output Line Driver for Single Ended Power Supply (PDF)
• High Quality Audio Mixer
• High Quality Sound Mixer
• Home theater system
• Improved PL tone decoder
• ISD4002-120 audio recording circuit
• JFET Bass Preamp
• Line level signal to microphone input adapter
• Linkwitz Cosine Burst Generator
• LM358 preamp
• Load Sensing Automatic Switch
• Loudspeaker Protection and Muting
• Loudspeaker Protection and Muting
• Low frequency / audio frequency dB output meter
• Low Noise Balanced Microphone Preamp
• Low Noise Microphone Preamplifier
• Magnetic cartridge amplifier
• Microcontroller (AT89C2051) based tachometer (PDF)
• Microphone Mixer
• Microphone mixer
• Microphone phantom power supply
• Minimalist Discrete Hi-Fi Preamp
• Minimum Theremin Kit Schematic
• Mono To Stereo Synthesizer / Simulator
• MS Stereo Decoder
• Musical Electronic Bell
• NE555 drives a speakes: Pulse Width Modulation Amplifier
• Noise-Canceling Headphones circuit diagram based on NE5322 opamps
• Novel buzzer using a relay and transformer
• Op Amp Limiter including SPICE simulation
• Panner Waveform Generator
• Parabolic microphone project circuit (can be used with shotgun directional microphone also)
• Paradoxical Sound Syntheizer
• Parametric And Sub-Woofer Equaliser
• Parametric And Sub-Woofer Equaliser
• Peak reading audio level meter using CA3140 opamp
• Peak-reading meters
• Phase shifter
• Phono Preamps For All
• Police Siren
• Power Amplifier Clipping Indicator
• Power Amplifier Clipping Indicator Circuit Diagram
• Precision Audio Millivoltmeter
• RC Audio Oscillator
• RDS Encoder
• Regulatable audio amplifier using a 741opamp
• RIAA Equalized Stereo Phono Preamp
• Room noise detector
• Room Noise Detector
• SCMS killer circuit for DAT decks using Sony CXD2601 signal processor chip
• Signal Detecting Auto Power-On Unit
• Simple electronic buzzer
• Simple light to sound converter with Youtube video
• Simple Surround Sound Decoder
• Simple surround sound decoder circuit schematic
• Simple two line output combiner
• Simplest Ever Amplifier Bridging
• Six-channel Mixer and Amplifier
• Slew rate control circuit diagrams
• Sound activated relay, V1
• Sound activated relay, V2
• Sound alarm based on LM741 opamp and LM386 amplifier
• Sound detector
• Sound Level Meter
• Sound level meter
• Sound operated switch
• Sound Pressure Level Meter
• Speaker cabinet simulator - professional-quality frequency response in a DIY-friendly circuit
• Speaker Microphone Circuit
• Speaker signals to line level inputs
• Speech recorded using ISD2560
• Spring reverb unit
• Stereo Audio Isolator
• Stereo Audio Isolator
• Stereo audio line driver for running audio over long distance cables
• Stereo Width Controllers
• Subwoofer Equaliser
• Subwoofer Filter, Gainer, Auto Power System
• Super mixer with microphone input / amplifier including a PCB layout
• Three channel audio spectrum analyzer
• Three channel audio spectrum analyzer
• Three-Level Audio Power Indicator
• Tone control circuit diagram
• Tone control circuit schematic
• Tone Control using TDA1524A Tone Control IC
• Tone detector circuit diagram
• Tone display system
• Tone generator circuit diagram
• Two Tone Audio Oscillator
• Underwater microphone used in a home aquarium to monitor fish sounds
• Use amplifier phono input as line level input
• Using a speaker as a microphone - impedance matching circuit
• Variable Amplifier Impedance
• Various tube crossover circuits
• Very loud beeper (PDF)
• Voice / Audio Record / Playback Circuit
• Voice Message Recorder / Player (uses an obsolete voice recorder chip)
• Voice Scrambler
• Voice-Over Circuit
• Voltage controlled amplifier
• Voltage controlled audio panner
• Voltage Controlled Panner
• Voltage Controlled Panner
• Voltage Controlled Panner
• VU And PPM Audio Metering
• VU And PPM Audio Metering
• VU Meter Amplifier
• Warbler siren circuit diagram
• Weird Sound Generator