I am a relatively newbie here and I am trying to build this project... so do not kick me hard and forget any stupid errors you see on the project. I appreciate any suggestions, criticism, etc., preferably with instructions on what to do. Talk to me like I am 3 years old. Show pictures... 😃
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This is a 4 stereo input switch. You press the key and you select the input key you want to send to the output.
First look at my power supply. I am using LM7810 and I have a resistor divider. So, My power supply is delivering +5V, 0 and -5V.
By having "negative voltage", I can setup the audio on the middle of the range and supply the MAX359 with positive and negative voltages.
I turn the whole thing on and it works almost perfectly. Every press of the switch and the next input is selected.
Now look at pins 8 and 9 of MAX359E (the switch). These lines enter on the potentiometers. The midle of the potentiometers go to the amplifier (TEA2025) and the other side of the potentiometer goes to -5V.
I have two problems with this circuit:
- Noise. It is humming like hell on the output.
- Another thing is that I am not sure if some voltages are correct. Suppose I put the multimeter's positive probe after C16 and the negative probe at -5V. If input U4 is not the selected input, that voltage is 5V as expected. As soon as I select U4, the voltage drops to 2.42V. I was not expecting that to drop.
Any ideas? Please remember to talk to me like I am 3 years old. Thanks.