OK, arecord -f S16_LE --channels=2 --device="hw:2,0" --rate=44100 junk.wav does work. It's not pretty, I have to amplify in Audacity about 40 db. My coupling capacitor seems to be leaky, I see DC on the waveform and I get some motorboating. But I did it twice and both times worked. What I did for a signal was just wet a finger and touch the center conductor of the soundcard input, which captures hum. I did a pattern of touching it and not touching it, what I see on the screen roughly matches what I did. So I need to build more amplification. On 7/20/20, chris hermansen <clhermansen@xxxxxxxxx> wrote: > Alan and list, > > On Mon, Jul 20, 2020 at 9:45 AM Alan Corey <alan01346@xxxxxxxxx> wrote: > >> When I do >> arecord -f S16_LE --channels=2 --device="hw:2,0" --rate=44100 junk.wav >> >> It doesn't complain but the recording is silence. Something may be >> turned down or off in the mixer. Or I'm recording the wrong >> subdevice. hw:2,1 and hw:2,2 don't seem to be found. If I amplify >> (40 db) in Audacity there's not really anything there. >> > > Alan have you tried running "alsamixer" in a terminal window and inspecting > the settings? > >> >> I'm using a bare electret cartridge with a 3.9 k resistor from 4.2 >> volts in from a lithium cell, and a 1 MFD coupling cap. I'd expect to >> see something when I tap on it, but nothing. >> > > Do you have a voltmeter to watch what happens on the output of the > capacitor and ground when you tap? > >> >> >> On 7/20/20, Alan Corey <alan01346@xxxxxxxxx> wrote: >> > Hmm, none of these are 1 channel. I do want 2 channels but so far >> > I've got 1 electret cartridge on prototype board trying to figure out >> > how much amplification I need. >> > >> > USB Sound Device at usb-3f980000.usb-1.5, full speed : USB Audio >> > >> > Playback: >> > Status: Stop >> > Interface 1 >> > Altset 1 >> > Format: S16_LE >> > Channels: 8 >> > Endpoint: 6 OUT (ADAPTIVE) >> > Rates: 44100, 48000 >> > Interface 1 >> > Altset 2 >> > Format: S16_LE >> > Channels: 2 >> > Endpoint: 6 OUT (ADAPTIVE) >> > Rates: 44100, 48000 >> > Interface 1 >> > Altset 3 >> > Format: S16_LE >> > Channels: 4 >> > Endpoint: 6 OUT (ADAPTIVE) >> > Rates: 44100, 48000 >> > Interface 1 >> > Altset 4 >> > Format: S16_LE >> > Channels: 6 >> > Endpoint: 6 OUT (ADAPTIVE) >> > Rates: 44100, 48000 >> > Interface 1 >> > Altset 5 >> > Format: S16_LE >> > Channels: 2 >> > Endpoint: 6 OUT (ADAPTIVE) >> > Rates: 96000 >> > >> > Capture: >> > Status: Stop >> > Interface 2 >> > Altset 1 >> > Format: S16_LE >> > Channels: 2 >> > Endpoint: 5 IN (ASYNC) >> > Rates: 44100, 48000 >> > >> > >> > >> > On 7/20/20, Clemens Ladisch via Alsa-user >> > <alsa-user@xxxxxxxxxxxxxxxxxxxxx> wrote: >> >> Alan Corey wrote: >> >>> arecord -f S16_LE -d 10 -r 16000 --channels=1 --device="hw:2,0" >> >>> /tmp/test-mic.wav >> >>> Recording WAVE '/tmp/test-mic.wav' : Signed 16 bit Little Endian, >> >>> Rate >> >>> 16000 Hz, Mono >> >>> arecord: set_params:1345: Channels count non available >> >> >> >> I suspect recording always uses channels. >> >> Please show the contents of /proc/asound/card2/stream0. >> >> >> >> >> >> Regards, >> >> Clemens >> >> >> >> >> >> _______________________________________________ >> >> Alsa-user mailing list >> >> Alsa-user@xxxxxxxxxxxxxxxxxxxxx >> >> https://lists.sourceforge.net/lists/listinfo/alsa-user >> >> >> > >> > >> > -- >> > ------------- >> > No, I won't call it "climate change", do you have a "reality problem"? >> > - >> > AB1JX >> > Cities are cages built to contain excess people and keep them from >> > cluttering up nature. >> > Impeach Impeach Impeach Impeach Impeach Impeach Impeach Impeach >> > >> >> >> -- >> ------------- >> No, I won't call it "climate change", do you have a "reality problem"? - >> AB1JX >> Cities are cages built to contain excess people and keep them from >> cluttering up nature. >> Impeach Impeach Impeach Impeach Impeach Impeach Impeach Impeach >> >> >> _______________________________________________ >> Alsa-user mailing list >> Alsa-user@xxxxxxxxxxxxxxxxxxxxx >> https://lists.sourceforge.net/lists/listinfo/alsa-user >> > > > -- > Chris Hermansen · clhermansen "at" gmail "dot" com > > C'est ma façon de parler. > -- ------------- No, I won't call it "climate change", do you have a "reality problem"? - AB1JX Cities are cages built to contain excess people and keep them from cluttering up nature. Impeach Impeach Impeach Impeach Impeach Impeach Impeach Impeach _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
