A&H iLive problem! (T112 + iDR48)

[hermanputter]

I can't register myself on the iLive forum for some reason... So I'm trying my luck here. This is also the message I sent to A&H support:

Our local University is presenting Oprah with an Honourary Doctorate. As you can imagine this is not just a simple overhanding of the papers. It has evolved into a serious production, and now my desk is giving me problems...

SHORT VERSION:
I recalled my preset scene again and just after I hit GO there was noise going to the PA. It sounded like full-blown running-away feedback, so loud I thought I might have blown the tweeters. Within a second or two it stopped and I was in my preset scene. We turned down the amps a little and did it again, it didn't happen every time, but i'd say 2 out of 3 times. And only between two specific scenes.


LONGER VERSION:
Some: Background:
We have a T112 and IDR48 mix rack. Running v1.81. We have our first show with it on Friday, started with rehearsals today. We're using all 48 inputs, about 16 outputs. We're also using inputs and outputs on the surface.

We have two HP Procurve 2510G switches, one at FOH and one at stage. With the mixrack and surface connected to the switches. The switches are connected to each other on a CAT5 about 60m long. Everything works fine...

Both the mixrack and the surface run through power-conditioners, so I don't suspect power-problems.

We had a couple of soundchecks today and I saved a scene for every band/group.
After rehearsal I was recalling all the scenes saved just having a quick look to make sure I didn't mess up any routing.
I recalled my preset scene again and just after I hit GO there was noise going to the PA. It sounded like full-blown running-away feedback, so loud I thought I might have blown the tweeters. Within a second or two it stopped and I was in my preset scene. We turned down the amps a little and did it again, it didn't happen every time, but i'd say 2 out of 3 times. And only between two specific scenes.

Luckily the PA is fine, but I'm scared using scenes now. What if this happens during the show...

If I can't find the solution I'll have to stay in 1 scene and just do everything manually, which is going to be a pain, but it's doable.

Thank you very much in advance.

[avkid]

I'm confused with one detail.
Why are you using switches?

[hermanputter]

We are planning to use fibre between the 2 switches. So the switch will basically just serve as a media-converter. We had the switches left over from an install (Got to use them for something). Just waiting on the fibre.

[avkid]

Are you aware that the control surface has a built in switch?

[hermanputter]

YES! I know.

The switches are redundent at the moment. BUT we will replace the CAT5 between the switches with Fibre. Neither the surface or the mixrack can take fibre...

[avkid]

Have you contacted the South African distributor?

Audiosure
43 Monte Carlo Crescent
Kyalami Business Park, P.o. Box 30914
Kyalami
Tel: +27 11 790 4600

First I would update your firmware to V1.82 just to be safe.

[bishopthomas]

If it's only doing it between two scenes then take a look at what's in the scene being recalled. It sounds like you may be sending the EFX send to itself, or maybe just a fader on one of the mixes got bumped by mistake right before you saved the scene. Turn off your amps, recall the scene (might as well check them all at this point) and check ALL of your settings.

If that all fails try removing this "switch." I'm not really sure why you're using it and what it has to do with running fiber.

[RZatAVL]

If it's only doing it between two scenes then take a look at what's in the scene being recalled. It sounds like you may be sending the EFX send to itself, or maybe just a fader on one of the mixes got bumped by mistake right before you saved the scene. Turn off your amps, recall the scene (might as well check them all at this point) and check ALL of your settings.

If that all fails try removing this "switch." I'm not really sure why you're using it and what it has to do with running fiber.

I agree it sounds like you have an internal feedback loop. Make sure that you don't have any of your fx returns routed back out to the wrong sends or something weird like that. If it is bad enough the channel will probly close after a while which may be why it goes away. I have always had little quirky issues with these consoles but never the one you are describing. I would call your dealer and get some support ASAP.

Good luck