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How can I use the TI ADS1243 8-channel ADC to convert a line-level audio signal (ideally balanced) to a digital 24-bit (as stated on data-sheet) stream.

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You can't. The datasheet is surprisingly vague on this point, but this is a low-speed ADC, intended for instrumentation applications. The analog bandwidth is just a few tens of Hz at most.

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You don't.

The ADS1243 datasheet gives an analog bandwidth of maximum 14.6 Hz.

That's well below what anyone would normally call audio.

The ADS1243 is intended for high resolution sampling of slow changing measurements - the datasheet mentions weight scales and blood analysis as intended uses.

Certainly nothing about using it in a stereo system.

There are multichannel 24 bit audio codecs out there. The ADS1243 isn't one of them, though.

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  • \$\begingroup\$ Do you know of any "multichannel 24 bit audio codecs" \$\endgroup\$ – James Conway Mar 31 at 11:58
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    \$\begingroup\$ Google barfed up a long list when I used that search term. Also, check Mouser or Digikey using those keywords. I've never built anything that needed such a beast. \$\endgroup\$ – JRE Mar 31 at 12:04
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    \$\begingroup\$ Something like this is the wildest I've ever used. Also low speed. The biggest difficulty you will have is in actually making use of 24 bits. It can be a challenge to keep noise and crosstalk down to the point that those 24 bits represent signal instead of noise. \$\endgroup\$ – JRE Mar 31 at 12:11
  • \$\begingroup\$ Something like mouser.co.uk/Texas-Instruments/Semiconductors/Interface-ICs/… be suitable? \$\endgroup\$ – James Conway Mar 31 at 12:13
  • \$\begingroup\$ @JamesConway That looks like an appropriate choice to me. \$\endgroup\$ – Alex Hajnal Mar 31 at 19:31
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The ADS1234 is a part designed for use in low bandwidth high resolution sensor sampling applications. In particular bridge style sensors are supported where gain is applied to the sensor reading and even 50/60 Hz filtering is performed. It indicates right in the "Features" section of the data sheet that signal sample rates of 10 or 80 samples per second are supported.

enter image description here

Audio sampling on the other hand is done at much higher rates. High performance audio sampling for CD is typically done at 44.1kHz and DVD at 48kHz. So as you can see, this device is not at all suitable for what you intend.

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    \$\begingroup\$ Okay, I have to ask, how did you do that cut effect in your image there? Do you use some screenshot software that automates it, or did you do it manually? \$\endgroup\$ – Hearth Mar 31 at 14:54
  • \$\begingroup\$ @Hearth - It is done manually in Microsoft Paint program. I could describe the steps that make it easy to if you are really interested. \$\endgroup\$ – Michael Karas Mar 31 at 17:09
  • \$\begingroup\$ Nah, I can see how to do it manually. I was just wondering if you had some quick and easy way to do it. Thanks! \$\endgroup\$ – Hearth Mar 31 at 18:18
  • \$\begingroup\$ Well my technique does not require me to do tedious manual erase of the text. \$\endgroup\$ – Michael Karas Mar 31 at 18:42
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From the datasheet

When a 2.4576MHz crystal is used, the device can be programmed for an output data rate of 15Hz, 7.5Hz, or 3.75Hz. Under these conditions, the digital filter rejects both 50Hz and 60Hz interference.

With a maximum datarate of 15Hz, I think you can kiss audio goodbye

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