Audio design

• Active CW Filter and Audio Amplifier
• Dynamic Noise Filter
• Microphone Preamplifier Electret
• Microphone Speech Processor
• Microphone Amplifier Low/High Impedance
• Class-A Headphone Amplifier
• Class-A Audio Amplifier
• Speech Processor - TL081
• Variable CW Bandpass Filter
• Variable CW Filter and Amplifier
• Audio Automatic Gain Control
• Baxandall Audio Filter
• Microphone Amplifier with ALC
• Audio Amplifier with mute control
• Noise Canceling Electret Microphones - WB9YBM
• Dynamic Microphone Preamplifier
• Speech Processor - All BJT
• Audio Preamplifier with Dynamic Noise Reduction
• Class-A HIFI Headphone Amplifier
• Super Class-A Low Distortion 3W Amplifier
• CW Audio Filter with Digital Selection - PY2MG
• Microphone Preamplifier with Tone Control - PY2MG
• Boosting Gain and Limiter of LM386 - VK3AWC
• Variable Audio LPF with MAX293
• 300 Hz - 3 kHz Microphone Filter
• VOX Circuit
• Voice Level Meter
• Microphone Dynamic Compressor
• 1kHz Sine Wave Oscillator
• High-Pass Low-Pass Microphone Preamplifier - N2MNN
• Passive Audio SSB-CW Filters - W3TS
• LC CW Band Pass Filters - DC8NR
• Audio Intelligibility Enhancer - N4GG
• Dual-Tone Audio Generator - VE3FIT
• RF Speech Clipper - DF4ZS
• 1W Audio Amplifier with Compressor
• Booster for Elektret Microphone