Music Sound to light converter

This was made by me when i was a kid, it was even published in a magazine, i think it will work, it was used on a very old huge ornamental valve philips stereo system in the remote speakers.

Passive volume control with Potentiometer

Recently i captured this circuit in eagle to publish online, it seems to have a small design error. It worked well for many years. The step-down transformer is used as a step-up here. The secondary winding was around 50mA so the resistance was protecting the 2N2222. C1 and R3 may need tweaking to get the desired adjustment range in R2.

GainClone Chipamp Audio Amplifier

The Source file is here del00005.zip

The voltage across the speaker is fed to C1-Gnd, which blocks DC component. R1, R2, R3 form a threshold bias for T1. 2N2222  chops the 12V DC in tune with the music. The chopped DC current flowing in the 12V winding of  TR1 is stepped up into AC pulses over 100V, this lights the Neon in flashes synchronizing in real-time with the beats. Known Issues - It does not perform well at low Bass like 20Hz.

Constant Current Source LED Drive - A safe and Simple Led Lighting Circuit.

Stereo Audio Music Players

40 Watts Hi-Fi Music System - Stereo Music player with Tuner, 1986, LED VU meter and Analog VU meter.  The Rainbow Sticker was to cover a deep Scratch on the Black Acrylic Facia or Front Panel. The Stereo Box and the Two Speaker Boxes all made of Wood, The Sound was pretty Good.

RCA connector or Phono Connector

This was done as repairing home electronics was my hobby in school days, I learnt by building Amplifiers based only on transistors from the Old Philips Circuits and Books. The above one is TDA2020 means 20 Watts Per Channel, with LED input level meter and moving-coil output meters. It would have a 5 pin din input and RCA speaker output, input for phono, tape, etc. The Speakers had a woofer, tweeter and midrange with passive crossover network.



Noise and Hum in Audio Circuits

 

Stereo Adapter for Portable Music Player Low Cost Stereo Adapter 20 Watts for Portable Music Player 1984, Bass Treble and Presence. The box was an Antique Medicine Chest or Organizer made of wood.

 

This was a TB810 based 10+10 Watts Stereo Amplifier with LM381 or 2 Preamplifier, The portable player docks in a wooden cabinet. There was no IR, Wi-Fi or Bluetooth in those days, so the device would interface with amp thru a stereo ear-phone socket-jack system .. Aux .. with a shielded cable. Bass, treble and Presence as per an old phillps audio amp book.

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