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
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
74dB Gain with LM386 - JF1OZL
Active Audio BPF 1kHz Bandwidth
Audio Squelch Circuit
High Dynamic Range Audio Compressor
Low Distortion CW Filter
SSB Audio Filter
Active Noise Canceling Headphones
Fourth-order Elliptic SSB LPF
Switched-Cap Variable Audio LPF
Voice 5 Band Equalizer
CW Filter - DL7HG
1W Audio Power Amplifier with LPF
Audio Limiter - DJ4BG
Ge-BJT Audio Power Amplifier
One BJT Audio Low Pass Filter
Simple Audio Sinusoidal Generator
3.5W Audio PA with Active CW Filter - W1FB
Simple FET Audio Filter
Variable Audio Notch Filter - K4VIZ
Voice Compressor with Filter
Dynamic Noise Limiter
Mike Preamplifier with Dynamic Compressor
40dB Audio Notch Filter
Microphone Equalizer and Dynamic Compressor - DL7MAJ
Audio T-Notch Filter - G3VFP
Microphone Frequency Booster - G3VFP
Pseudo Stereo CW - G3VFP
Tone Meter - W1GHZ
Subaudible Tone Encoder - W4NFR
Dynamic Mike Preamplifier for IC-706 - W5RK
Magical Audio Filter - W6QIF
Noise Limiter - K8MKB
Pseudo CW Filter
Microphone Preamp Compressor - VE3GSP
CW Regenerator/Processor - W6GXN
Speech Processor with ALC - K9EUI
Headphone MOSFET Amplifier
Low Noise Compressor Clipper - VE3GSP
Masher Speech Processor
Single-Stage Push-Pull Audio Power Amplifier
50dB Dynamic Range Compressor
Differential Low-Noise Mike Amplifier
Speech Expander - VE1BZJ
Speech Processor - W0YBF
3.5W Low Distortion Audio Power Amplifier
Speech Processor for Electret Mike
