Zoom H4n Pro not seen as recording device in Audacity but works with arecord

[Mint Platz]

Hi!

This is a weird one: I wanted to use my Zoom H4n Pro as a recording device with Linux Mint Mate 21.2 and kernel 6.5.0-14-generic. lusb tells me

Bus 002 Device 009: ID 1686:0045 ZOOM Corporation Handy Recorder stereo mix

, cat /proc/asound/cards shows

2 [H4]: USB-Audio - H4
ZOOM Corporation H4 at usb-0000:00:1d.0-1.4.2, full speed

and I can even record from it using the terminal with

arecord -D hw:2 -f cd foo.wav

. So from a hardware/driver perspective, things seem fine.

However the device only sporadically shows up in the "Sound Preferences" applet,

pulseaudio -k

typically helps to refresh. But once I click some radio buttons in "Choose a device for sound input" in the "Input" tab, the entries related to my Zoom H4n Pro disappear and I'm left with "Monitor of Built-in Audio Analog Stereo" being the only available option.

If Audacity is already open and I immediately start a recording after pulseaudio -k, the first attempt succeeds but as soon as I click "Play", the H4n device is gone.

So there obviously is something going on (could be how Audacity handles input devices as well) that makes Pulse Audio revert to some default setting whenever I try to record. arecord from the console works every time, but it is quite tedious if you're used to an Audacity workflow. I don't have pavucontrol installed because I don't really need it and I also worry that it might interfere with the Sound Preferences applet that comes with Linux Mint by default.

I also tested the Jabra Speak 410 handsfree station I had available. This seems to reliably work as an input/microphone device and as on output device/loudspeaker. For as long as the device is attached, the sound preferences dialog shows "Jabra SPEAK 410 Mono" in the input tab and "Jabra SPEAK Analog Stereo" in the output tab. I can record from and play with it as often as I want in Audacity.

The Zoom H4n Pro on the other hand always shows up in the sound preferences dialog after executing pulseaudio -k. I can then start Audacity, start/stop monitoring and record from the Zoom H4n Pro (shown as "Handy Recorder stereo mix Analog Stereo" in the input tab of sound preferences) as often as I want.

But the moment I hit the "Play" button in Audacity, the Zoom device is gone from the list of input devices in sound preferences and not coming back unless I run pulseaudio -k again.

Updated the Zoom's firmware to 1.10, did not change anything. Using different USB cables or ports did not make a difference either. So the issue could also be how Audacity adresses input devices or what it does to play audio which sort of messes things up in conjunction with the Zoom's firmware.

And finally: The issue does not seem to show up on Linux Mint 19.1 Tessa with Kernel 4.15.0-20-generic #21-Ubuntu. That is a different motherboard (ASUS B365M-K instead of P7P55D) but I doubt that it makes a difference at that level.

If you want me to test something or provide more logs, just go ahead. Any help highly appreciated. Thank you.