Behringer UM2 now only sending on one channel?

A small group of us in the north of the UK are returning to use of JackTrip after a break of a year or so (a long story) but we have just discovered that our Digital Bridges with Behringer UM2 interfaces (two inputs used for instrument + mic) now only send on the MIC/Line 1 input - the INST 2 input no longer appears to work. The Input Channels option on Audio Devices apparently has no effect and there no longer seems to be a Mono/Stereo option on the Virtual Studio setup. Other interfaces we have in our group (e.g. Focusrite) and our Analog Bridges work as expected. Unfortunately I can’t pin down when this stopped working as they’ve not been in use, but it was all working very well until May 2021. Has anyone else found this problem & is there a fix for it?

[Update 25th June: The Behringer UM2 works as expected on my iMac running JackTrip 1.6.1 - both channels work correctly.]

BTW some of us tried a brief session today while testing this out and were amazed by the ease of use and performance improvements made over the last 12 months - so congratulations & thanks to all concerned. We are reviewing our use of JackTrip again in view of the increased costs of meeting in person (mainly fuel costs) and health issues among some of our players. These improvements all make JackTrip increasingly attractive.

Hey there, this is the first I’ve heard about issues with the UM2 + digital bridge- we’ve been recommending that interface for a while and would definitely like to understand whether it’s systematically broken somehow…

Your head goes where mine would too- first to check audio devices for input channels = 2. Then check soundscape or studio settings for stereo (we’ve actually removed the ability to switch studios to mono, just wasn’t worth the headache). Then, I’d check it against a difference machine, like your iMac.

Any info we can get from the rpi itself? Are you able to open alsamixer and see the instrument channel? Are you able to see the connections from both channels in JACK?

I can’t help but suggest that since it’s working great on iMac, that you use the JackTrip app to connect instead of a bridge :). But of course it should work for both.

Thanks for your comments Andrew.

I’ve since confirmed that the UM2 works ok on a Windows 10 desktop, but I had to install the specific Behringer drivers. That’s a short term option for our (80 year old) drummer who is currently stuck at home for 6 weeks following a hip operation. He normally uses the RPi and UM2 but has a Windows laptop.

I normally use an analog bridge (connected via my Tascam Model 24 mixer) and have just tried the UM2 into that, enabling USB audio option. The UM2 behaves in the same way - mono on Mic/Line input 1 only and mono on its headphone socket. The Hi-Fi Berry card on the analog bridge provides stereo in/out as expected.

I’ll try to take a look with the alsamixer. I think I have some notes notes from last summer for how to do this.

Update: The UM2 works fine locally on the RPi in stereo using speaker-test and alsamixer to control the output levels going to the headphone socket on the UM2. I’ve also used the Vu meter option of the arecord utility to confirm that both the UM2 inputs correctly in stereo.

I’ve now set up a locally managed JackTrip virtual studio on my LAN using my MBP laptop & have connected the digital bridge to this. This auto connected the Send / Receive loopback channels as expected on the JACK server, but only send_1 to receive_1 produced any audio. Nothing on send_2 receive_2 loopback. I then tried cross connecting send_1 → receive_2 and send_2 → receive_1 which produced no audio at all. I guess from this that only the first UM2 channel in both directions is being processed?

Hello, one of the developers here - are you able to get SSH access into a digital bridge where you’re seeing this issue? It seems like you’re pretty technical so I figured I’d ask :slight_smile: Here’s a few “how to SSH” references:

Once you’re in, could you run the following commands and report back what you see?

arecord -l

The above command reports all the soundcards available, after which you can run the following to show information on the specific card by number:

amixer -c 0 scontents
amixer -c 1 scontents
# etc.

If you’re having any difficulties getting inside the Bridge, feel free to submit a help request here and I’d be more than happy to follow up with you on a call or something!

Here are my results. I hope they are useful

pi@jacktrip:~$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0

pi@jacktrip:~$ amixer -c 1 scontents
Simple mixer control 'PCM',0
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 128
Mono:
Front Left: Playback 128 [100%] [0.00dB] [on]
Front Right: Playback 128 [100%] [0.00dB] [on]

Thank you!

That’s helpful, it’s interesting that “PCM” is your only alsa control for this UM2. If I’m interpreting it correctly, since this only has Capabilities: pvolume pswitch ... this is only playback (what you hear) and there is no capture (what you send) controls whatsoever. That makes even the one-channel sending more curious.

I have a few more commands for you to run. With your device plugged in as-is and detected under “card 1”, could you report the output of these commands?

amixer -c 1 controls
ls /proc/asound/card1
cat /proc/asound/card1/stream0

Thanks Nelson,
Here’s further info as requested…

pi@jacktrip:~$ amixer -c 1 controls
numid=5,iface=CARD,name='Keep Interface'
numid=3,iface=MIXER,name='PCM Playback Switch'
numid=4,iface=MIXER,name='PCM Playback Volume'
numid=2,iface=PCM,name='Capture Channel Map'
numid=1,iface=PCM,name='Playback Channel Map'

pi@jacktrip:~$ ls /proc/asound/card1
id  pcm0c  pcm0p  stream0  usbbus  usbid  usbmixer

pi@jacktrip:~$ cat /proc/asound/card1/stream0 | less
Burr-Brown from TI USB Audio CODEC at usb-0000:01:00.0-1.1, full speed : USB Audio

Playback:
  Status: Stop
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 16
    Channel map: FL FR
  Interface 1
    Altset 2
    Format: S16_LE
    Channels: 1
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 16
    Channel map: MONO
  Interface 1
    Altset 3
    Format: S8
    Channels: 2
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 8
    Channel map: FL FR
  Interface 1
    Altset 4
    Format: S8
    Channels: 1
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 8
    Channel map: MONO
  Interface 1
    Altset 5
    Format: U8
    Channels: 2
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 8
    Channel map: FL FR
  Interface 1
    Altset 6
    Format: U8
    Channels: 1
    Endpoint: 2 OUT (ADAPTIVE)
    Rates: 32000, 44100, 48000
    Bits: 8
    Channel map: MONO

Capture:
  Status: Stop
  Interface 2
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 48000
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 2
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 48000
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 3
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 44100
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 4
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 44100
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 5
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 32000
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 6
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 32000
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 7
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 22050
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 8
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 22050
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 9
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 16000
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 10
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 16000
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 11
    Format: S8
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 16000
    Bits: 8
    Channel map: FL FR
  Interface 2
    Altset 12
    Format: S8
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 16000
    Bits: 8
    Channel map: MONO
  Interface 2
    Altset 13
    Format: S8
    Channels: 2
    Endpoint: 4 IN (ASYNC)
    Rates: 8000
    Bits: 8
    Channel map: FL FR
  Interface 2
    Altset 14
    Format: S8
    Channels: 1
    Endpoint: 4 IN (ASYNC)
    Rates: 8000
    Bits: 8
    Channel map: MONO
  Interface 2
    Altset 15
    Format: S16_LE
    Channels: 2
    Endpoint: 4 IN (SYNC)
    Rates: 11025
    Bits: 16
    Channel map: FL FR
  Interface 2
    Altset 16
    Format: S16_LE
    Channels: 1
    Endpoint: 4 IN (SYNC)
    Rates: 11025
    Bits: 16
    Channel map: MONO
  Interface 2
    Altset 17
    Format: S8
    Channels: 2
    Endpoint: 4 IN (SYNC)
    Rates: 11025
    Bits: 8
    Channel map: FL FR
  Interface 2
    Altset 18
    Format: S8
    Channels: 1
    Endpoint: 4 IN (SYNC)
    Rates: 11025
    Bits: 8
    Channel map: MONO

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Great, thanks! I think I might have a lead and possible fix. Would you be open to hopping on a Zoom meeting sometime? We can coordinate through the help ticket.

Wonderful - yes, Zoom will be fine. I can be available most of the day UK time except 18:00-20:30 today and 12:00-15:00 tomorrow (1st). Does that work?

Hello! Sorry for the short notice, it’s morning here where I am. I’ll be here until 18:00 UK time if you’d like to hop in, otherwise I’ll sign on again at 20:30: Launch Meeting - Zoom

Hi Nelson. I’m back at my desk - currently 20:33 UK time & I’l be here for another couple of hours. Unfortunately the Zoom meeting link you sent is apparently invalid & I was unable to join.

Wanna try this one? Launch Meeting - Zoom

Hi Nelson,
Many thanks for the Zoom session last night & your assistance in fixing this problem.

I’ve just confirmed this also works as expected with the Analog Bridge (USB Audio enabled) which updated itself when I switched on this morning.

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