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Recording and playback on DAC+ADC Pro

brm

July 02, 2023 01:15

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Hardware is Raspberry PI 4 and DAC + ADC PRO hat.

Hi all. My latest foray into recording turntable LP soundtracks continues.

Software is Rasb Pi OS  with Alsa and Audacity software

My question is this. Can I record and playback at the same time?

I can capture and record ok using Audacity software. Can I output to an amplifier at the same time? If not - how do you use alsa for playback

from say a recorded .wav file? Do I require any special settings?

Alsa mixer shows Capture, Playback and (All) in its settings (F6)

but so far I cannot get playback working.

 

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4 comments

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  HiFiBerry team July 03, 2023 08:34

  Playback and record work simultaneously ONLY if they are using exactly the same parameters (sample rate, sample format). 
  
  To play back a recorded file, I recommend the "mplayer" command line tool. 

• 0
  
  brm July 04, 2023 23:37

  Using Audacity is working well at the moment. As discussed earlier, I find it useful to have playback happening for some recordings. Audacity has a menu item Software Playthrough (on/off). When this is turned on, I am able to get sound to my speakers while recording. These can be found in Transport > Transport Options menu. The default setting in this menu is to have Overdub on. This did not allow any playback. When this is turned off and Software playthrough is activated then both LEDs are visible on the DAC+ ADC Pro board.

  My question is - am I hearing the recorded sound ? Is it just the analogue sound or digital. Sorry if I am unclear on this.

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  HiFiBerry team July 05, 2023 10:57

  That's the expected behaviour. If you enable software passthrough, both input and output are in use and can't be used by anything else (e.g. another playback process).

• 0
  
  HiFiBerry team July 05, 2023 10:58

  With software playthrough you will hear the recorded sound. However, I'm not sure if audacity does any post-processing of the data or if it just plays these unmodified.