Audio Kits
Mini audio compressor schematic
This mini audio compressor circuit use only one active component T1. The audio signal goes thru C1, R1, D1, C2, R3. Still a part of audio signal charge the D3/D4 detector and creates a control voltage for T1.
The fading time depends on C4 and R5. With an audio input variation of 50dB, the output signal [...]
Simple mixer circuit schematic - Common base
The mixer schematic is build on common base principle, where input voltages are transformed in alternative currents wich are summed to form the alternative current component for the collector. The total amplification is R6 / Ri, where Ri is one of the input resistors. I’ve build this mixer for a little transmitter and works great.
3 Band graphic equalizer LM833
The main component of this 3 band graphic equalizer is LM 833 produced by National Semiconductor.
LM833 has a very low noise, and a band / amplifier of 15MHz and a rise speed of 7V/s. The cut points for low frequencies are 200 Hz and 2 Khz for high frequencies. Maximum attenuation is 16 dB. The [...]
