I'm a professional software engineer looking into figuring out how to decode audio signals from a guitar cable.

Essentially I bought a cable that has a guitar jack connector in one end and an USB into another, I can easily read the data from the usb using software, the only concept I don't understand is what the signal itself is made of, how is a wave represented by the signals that are generated by the guitar jack?

  • Hi, please check out the guidelines for questions. You haven't told us what kind of output your guitar is generating. What sort of "professional engineer" are you? I ask because anyone in the field of Electrical Engineering will understand the difference between a digital data packet and an analog waveform. – Carl Witthoft Oct 12 '20 at 15:19
  • software engineer – anon11112 Oct 12 '20 at 15:20
  • Essentially, this is research that was first commercialised 35 years ago [anyone remember the Sony F1?] & single-chip DACs dropped below the 'magic' 10¢ cost 15 years ago.. You've a lot of reading to do. – Tetsujin Oct 12 '20 at 15:43
  • Imho this question is a bit broad. First the audio signal is sampled, and there are different ways to do that. Then the samples are probably encoded in some way either proprietary to the sound card or available as part of an operating system API, then that is again encoded to comply with the USB standard used by the card so it can be transmitted to the computer, then the layers are decoded again so the original sample stream is available to software. Which aspect of all of that are you asking about? If the whole thing, that seems too broad. And some parts of that are off topic. – Todd Wilcox Oct 12 '20 at 17:37
  • 3
    Given that the SE/SO network has many other sites about software engineer and analog signal sampling, etc., I suggest you ask this question on a different site in the network. This site is a little bit about music technology, but it’s more about music than technology. And the technology you’re asking about is essentially the same when used on any analog signal processing, it’s not specific to music. – Todd Wilcox Oct 12 '20 at 17:40

The "cable" you purchased is (most probably) an audio interface. Its critical part is analog to digital converter (ADC). The data stream are ADC readouts of the guitar signal repeated many times per second. Each ADC readout is typically 16 bit or 24 bit integer, and typical rates (numbers of ADC readouts per second) are 44.1 kHz, 48 kHz, 96 kHz...

  • i've worked extensively with sound sampling in the past. However i haven't actually went as far as reading into the output of a sound card. It makes a lot of sense for the usb to stream samples. – anon11112 Oct 12 '20 at 15:59
  • It is aslo possible that data are not completely streamed but sent by "packets"… The easiest is to ask the audio driver to fill up your circular buffer haha. – Tom Oct 12 '20 at 16:05

Not the answer you're looking for? Browse other questions tagged or ask your own question.