QU24 drops all signals for a second

[MegaUnbalancedParticipant]

We just premiered a show which will be running for the next two months ten times a week, about 400 people / show. Everything has been smooth with Qu24 until a couple of days before the premiere. We started having seldom approx. 1 sec long dropouts/silences, occurring once per show. Needless to say this is very worrying. The droputs/glitches seem to mute everything from the desk for a short while. I have not really been able to react soon enough to find if the whole desk freezes or if it is only the outputs/audio side. The dropout occurred once with my sound card connected to the local inputs and while listening through mixer/headphones, so I’m pretty confident it’s the desk.

For the show tonight I replaced our voltage regulator with an UPS with no difference. The dropout still happened once. We are also using AR2412 with a 75m double shielded cat5e cable. No network devices attached to the desk. USB stick has been connected all the time without a problem, if that matters. Firmware 1.90 REV4537. DAC temperature around 70C. We use Ableton Live through USB to Qu24 as a midi i/o device to run the mute automation for the desk. No internal scenes are used from the desk. All sounds are run through external audio interfaces so no audio i/o through USB to Qu24. Soft keys are used to send midi to Live for triggering scenes and some samples.

We need to react fast with this so I would appreciate your thoughts. After Sunday show there are two free days, so we have to solve this during Monday and Tuesday one way or another.

[MegaUnbalancedParticipant]

I forgot to add that the dropout seems to occur without user intervention, while not touching the mixer. A while before the premiere I did update the Qu24 channel mute automation for every Live scene so that it sends mute/unmute messages for every Qu24 channel in use (about 70 Live scenes for the whole show). But I would be surprised if that has an effect on this. Anyway the problem seems to happen while not triggering any scenes and sending midi from Live.

[garyhParticipant]

This almost sounds like the same problem many people have with noise when using usb streaming. The problem has to do with the Intel usb 3 chips in the computer. This may also be causing noise on the midi channel which ends up randomly muting the board. You might look through the posts having to do with usb noise to find a remedy.

[BRSParticipant]

Garyh’s comment is good.

Another thought – instigating or removing phantom power temporarily mutes a channel. Could there be a midi message which switches this to all channels?

Or perhaps a dodgy XLR lead which is shorting a channel and causing the phantom power to duck on the AR2412.

Good luck. Do report back when you find it.

[MegaUnbalancedParticipant]

Thanks guys. One thing I also forgot to mention was that some time before the premiere I switched from my own MacBook Pro to companys MacBook Pro. The company machine has only usb3 ports, mine has usb2.

I switched back to my MacBook for todays show and there were no dropouts.. It seems that only connecting using usb3 port can screw things up. It must be just a hardware problem/freeze with the desk when our Mac is connected with usb3, I don’t think midi itself plays a part in this.

Well, since we can’t use the company machine I just have to leave my personal one there and get also an extra one with Live license as a spare. One option might be to use an usb2 hub between the company Mac and qu24, but since we are already performing the show I will rather not start experimenting.

I’m going to write to the back of this desk “Most likely not compatible with USB3, at least with intel ones”. It could have been written to the first page of qu manual also.. With big letters. Would have spared us from a few scary moments.

[leachyParticipant]

Hi There
We are having this Problem with our QU24 Desk. We also run the AR2412 with Cat 5 shielded cable. All runs fine but then randomly on live band shows in our venue the whole desk mutes to silence for approx 4 to 5 seconds. All the green signal lights just stop and then reactivate and then resumes without issue. I thought it might be a limiter on our Crossover but its happening from the Desk end we think. Its really worrying as we are on edge hoping it wont drop out again and low and behold it Does,

Could it be a dodgy XLR? Can you advise soonest please

[MegaUnbalancedParticipant]

Do you have anything connected to the Qu24 back USB port? If so, make sure you are using usb2 ports on your computer, not usb3, as stated above. But I guess you already read the whole thread. We managed to sort our problem by using usb2 connections instead of usb3. I can’t remember for sure though if we encountered an occasional small glitch at some point after that. But the system behaved ok for the most part after we changed to usb2. Nowadays this venue is using SQ5 and there have been no glitches or odd problems with connectivity as far as I know.

Just to be sure, is your AR2412 connected with single cable (no extender adapters etc.) and is it connected well?

Cheers, I hope you will find the problem.

[Alex A&HKeymaster]

Hi Leachy,

It sounds like the input signal is dropping out from your description, so I would recommend looking at the AR2412/CAT5 cable for issues.

How long is your CAT5 cable?
Is it STP (Shielded Twisted Pair) type?
Have you tried a different cable to see if the behaviour changes?

Is the ready light still illuminated on the Ar2412 when the drop occurs?

Thanks
Alex

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