I currently have a FP2 using a simple straight through cable to connect the audio jack to an external device. I would like to get a FP4 but am confused about the DAC that is part of the FP USB to Audio Jack adapter.
Is the signal coming from FP2’s audio jack an analog signal, whereas the signal coming from the FP4 USB port a digital signal (therefore requiring the DAC)?
If that is so, could someone explain to me at what points in mobile telephony the audio signal of a person’s voice is converted to a digital signal and vice-versa?
Generally all audio is converted to digital and back so that it can be recorded etc. So in the FP2 it was reconverted to analogue for the jack. In the FP4 there is no jack so it has to be done via an adapter or in a specialist headset.
Mobile telephony covers both analogue and digital. Old two way handsets used audio which was imposed upon a carrier which was later subtracted.
Once it was clear than the analogue could be sampled frequently enough to be intelligible it became possible to send information digitally a bit like Morse code. So the mic input is converted to digital as soon as re-analogued as late as possible.
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