Audio in from mp3 player help.

CameronM

Hello, I am trying to do an audio project that involves an audio input and audio output. I am currently stuck on the audio input part of this project. Basically I am simply trying to take the audio input from a little mp3 player and using the prop under a certain circumstance to play the audio that's coming from the audio input and play that through speakers or headphones. Right now I am using Kye's ADC Engine for the input part of my software. For my circuit I noticed after trying multiple times using the circuit that kye provides, that I need the audio input from the mp3 player to be amplified. So I bought a TDA7052A to amplify the signal, but when I play the audio from the mp3 player through the prop It almost sounds that the music is to loud and I can not hear whats playing clearly. In addition I have to have my mp3 player cranked up to max because any thing below a little more than half way does not pickup and is not played. But when I take out the prop and just play the amplified signal it sounds just fine.

So, does anyone have any suggestions on how to get better quality with the prop and the TDA7052A?
Is the TDA7052A even the right chip for this or should I go with a preamplifier?

For the TDA7052A circuit I am using the cicuit provided in the datasheet.
http://media.digikey.com/pdf/Data%20Sheets/NXP%20PDFs/TDA7052A_AT.pdf

Any suggestion would help.
Thank you,

CameronM

Kye

Um, you actually want the audio not to be amplified from the input source. You want to just turn the volume up in the prop chip when it outputs it.

Can I ask why you need to do this? Having the audio go through the prop chip only results in degradation of the audio quality. I posted up a new KISS wav player and KISS wav recorder program that should more easily be able to do what you want. You can then just have all your files on an SD card and play them back at any time.

StefanL38

as kye already mentioned converting an anlog signal to digital and then converting it back to analog results in a more or less loss of quality.

If you don't mind please describe what you want to do in the end.

If it is just automatic switching between headphones and speakers just use relays.

If you want the prop to control the volume a voltage controlled ANALOG amplifier will do much better.

Just the analog to digital-converter for creating CD-quality in a professional studio will cost thousands of dollars.
From a propeller with simple ADC-circuits you can't expect HiFi-quality.

Again please tell us what you want to do in the end.

keep the questions coming
best regards

Stefan

CameronM

Thank you both for your response. What I want my end result to be is a simple audio switch where I can control multiple inputs and choose which input is played through head phones or through the television. But, I would like to control this by using an IR remote which is where the prop comes to play. So am I basically over complicating this by running the audio through the prop and also losing quality? Would I then be better off using some relays?

Thank you,

CameronM

CameronM

After doing a little research I think a relay would be much more appropriate for what I am doing. I really never had a need for relays which is why I never gave it a thought to use or research. However, if there are any more suggestion I would a appreciate it.

Thank you,

CameronM

Kye

Nah, that's the best way. Good luck.

DonEduardo

An analog switch IC might be what you are looking for, such as CD74HC4067. Sparkfun sells a breakout board since it's a surface mount device. I did a similar project a couple years back switching multiple video/audio signals to my TV using the Propeller as the control device. I don't think the chip above is suitable for video but should be fast enough for audio. Maybe someone that has used the chip can comment. The chip I used was end of life and doesn't seem to be available any more(PI3V314BE).

CameronM

Thank you DonEduardo for the suggestion I will have to check that out too.

Thank you,

CameronM