"Ticking" noise in every channel with phantom power enabled

Qu Qu Troubleshooting
1

Hi all,

We have a QU32, and there is a very noticeable, electronic “ticking” sound present on all local inputs with phantom power enabled (or, more specifically, with a condenser microphone attached). The “ticks” are precisely regular, and can be heard through the outputs, and seen on the input stage meters. The volume of the “ticking” is proportional to the preamp gain on that channel.

Has anyone experienced this problem before? Can anyone make any recommendations on how to solve it?

Thanks for your help!

2

Sounds bad - Do you have any stage boxes (to eliminate preamp related issues) or a phantom power injector (to eliminate that bit of circuitry)?

Does it occur with phantom powered DI boxes?
With and without signal?

3

Install situation or multiple locations? The “precisely regular” has me thinking it’s coming from source power.

4

Have you tried it with all of the inputs disconnected at the mixer?

5

Yes, the regularity points toward the power. Throw a UPS on it and see if the tick goes away.

You’ll probably want a UPS in your set-up at any rate.

6

hmmm interesting:

present on all local inputs with phantom power enabled

Do you have an AR unit and is the tick also coming from there?

7

I’ve done some further troubleshooting.

There is clearly a problem with Phantom Power on inputs 17 through 32. When those inputs are powering a DI box, the lights on the DI actually pusle.

Adding a UPS to the system does not affect the ticking in any way.

I feel the desk will have to go in for a service, needing power supply repair.

Has anyone else experienced this problem before?

8

It not channels 1-16?

Wonder if the 48v convertor is separate?

9

Yes, channels 1 to 16 are perfectly fine!

10

Sounds like there are two circuits generating the 48V, and one of them is kaput.

Short term - don’t put phantom devices on the higher channels :stuck_out_tongue:

Otherwise looks like a warranty fix to me.

11

I have the some problem, but with evry chanal that has 48v on. any suggestions?
Thank you very much.
This is what I HAVE DONE SO FAR:
1.- check cables and mics
2.- Hard reset on mixes
3.- unplug everything and see if it ticks (no ticking)

12

With you point #3 everything unplugged and no ticking.
Maybe try plugging channels back in one at a time and see if it’s
one input causing the issue.

It’s a stretch I know!!