Electronics Projects, Parallel Port Audio Output TDA7050 Amplifier D-A Converter LPT article
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LPT parallel port output audio output to use as a simple circuit output stage audio to reinforce tda7050 used this integrated general mp3 player in headphones kllanılıy supply chassis and audio input terminals with attention to the different integrated used in the example tda2822
Involvement surprisingly worked on the first try :). First, I tested the LPT port of your PC and to measure how and to what extent the supply voltage drops Followers of the remaining data lines. I recorded a decline of 4.5 V to 3.1 V, which is quite enough for the amplifier. Trimmer I had to reduce the gain of the amplifier, because it was too large to extreme overdrive ironically stopped playing altogether. I suspected that the ports on the laptop are sick, which was also confirmed at the drop of 4.7 V to 2.0 V. For normal listening it still was enough, but přecijen when I was a little more ohulil so’ve started enough to distort. So I went to the external power supply, which I took out of the box one wire to the diode (the cathode), which is inserted into the tube anode PS / 2 connector (+5 V) for external keyboard.
LPT Audio Circuit Project
Active Covox (D / A converter to a parallel port) So I once thought that I could for my old laptop (Dell Latitude P120/16MB RAM, no sound card) to try to build this crazy, you guys had built in the days when he stood some SoundBlaster 10000, -. So I do not remember those times, but this connection has something to it. My requirements were such that I could listen to headphones, powered directly from Covox LPT without other auxiliary sources, amplifiers and the like. But when I researched about it, so I thought it was stupid to do it in small burden resistors and output directly to the headphones, IMHO it threw the load nicely. So I decided to make another variant – friend advised me circuit TDA7050 for 30, – (GME), which I used as a built-in amplifier powered from the remaining lines LPT. Circuit has already operate from 1.6 V above. Output impedance is 32ohm. Resistor R-2R network I did the 10k and 20k 1% SMD resistors. The whole I did it stick them on double-sided printed circuit board (yes, I made do with lihovkou) into the housing cannon connector.
source http://rayer.ic.cz/elektro/covox.htm Active Covox (D-A converter to a parallel port) circuit schematic files alternative link: parallel-port-audio-output-tda7050-amplifier-d-a-converter-lpt.rar