ADA8000

[RBIngraham]

Sorry, I am hoping this doesn't lead to a big long debate about the ADA8000s.... really...

But I am curious if anyone else has run into some of the same issues I've had on several occasions now.

What happens is suddenly I'll get a fairly high level of white noise on a channel. It pretty much makes the channel unusable. I've had it happen on just a single input on a unit. I've had it happen to an adjacent pair as well.

I don't think it's one particular unit because it has happened on at least 3 out the 5 ADA units that I own.

It happened again this past Saturday evening. In this case I cycled the power on the unit... problem gone. Worked fine for the show and the next day as well. Some times it has not gone away with a power cycle, but it would go away when I came in the next day.

I thought, well maybe it's something to do with my 2408, but this past weekend it was hooked up to a different 2408, so that means it's happened on two different 2408 units. It is not the MOTU PCI card because it's happened on 2 different PCI cards with 2 different (although both Shuttles) computers. Also, none of the other I/O boxes show any signs of this issue, so I really don't think it's the MOTU, but I guess I can not be certain until I use some other A-D-A units at some point.

I am not 100% certain but I do think it happened when using these units with my Echo sound cards at least once so I don't think it's exclusive to the MOTU cards, but I'm not 100% certain about that.

The only other thing that I have not eliminated is a AC power issue. I think it's only been in this one facility (the theatre has 2 venues), so maybe it is just something with this place I don't know. But I have not had issues related to AC power in the space before, well... except when we had the power go out but that's not the building's fault. And the last couple of times this has been happening in the mainstage, so that venue actually has dedicated sound power... not transformer isolated, but it's own panel that feeds the entire system with IG outlets.

So I'm just curious am I the only one that has had this issue pop up. I would say it's happened about 3 or 4 times since this past Sept. It's never been a show stopper, I just patched around the one channel to an open one or as I said, sometimes I just cycle the power and it's gone.

Weird.

[venez03]

Ive had similar issue, but likewise usually goes away with power being cycled.

[RBIngraham]

Thanks, glad to know it's not just me.

Oh.. and before anyone asks... No I don't use a step down transformer.

[ssrsound]

Yeah -- I've seen the same thing. When it happens, it always happens at power-on, and stays. If I power cycle it, it goes away. I've never had one develop something like this *after* power-up, so it's not been an issue (since I generally power everything up and check the console for issues before I do anything else).

I suspect it's a sync issue of some sort... probably a clock issue.

[RBIngraham]

Yeah -- I've seen the same thing. When it happens, it always happens at power-on, and stays. If I power cycle it, it goes away. I've never had one develop something like this *after* power-up, so it's not been an issue (since I generally power everything up and check the console for issues before I do anything else).

I suspect it's a sync issue of some sort... probably a clock issue.

Maybe it's worth a shot of going back to using a dedicated wordclock then. I just didn't suspect a sync issue since it's usually only been a single channel of a single ADA unit.

[Ogmeister]

I have had this same problem and found that in my case this was caused by self oscillation of the output OP AMP. I tracked this down to a cap in the feedback loop that was not securely soldered to the board and created an intermittent connection. Cycling the power fixed it temporarily until one day it was doing it all the time.

[DaveS]

You might want to check your optical cables. I experienced something similar and it seemed to go away after I reseated the optical cable going into the unit. I've been toying with the idea of hotgluing the cables in place - it's not permanent but does keep things in place.

Might just be coincidence...it's digital after all and it should be all or nothing....

Oh - also check your sync switch in the back...they don't seem to be really solid and I've had to re-set mine a few times.

[RBIngraham]

I'm pretty darn positive it's not the sync switch. I'm not moving my stuff around, it's in a rack that is set up in the venue and at this point in time it hasn't really moved much since December.

So little reason it would have been moved. And at least in my case if it was bumped the sync light would not be lit.

[DaveS]

I wouldn't discount the sync switch even if the units haven't been moved - vibrations can cause inexpensive switches to migrate their position - and the ones on the ADA's (on mine at least) do not lock into place very securely. Also, I don't know how 'clean' they are when they are installed - might be slight corrosion or tarnishing on the contacts.

However, if your sync lights are staying on you're probably ok in that respect.

[gdougherty]

I wouldn't discount the sync switch even if the units haven't been moved - vibrations can cause inexpensive switches to migrate their position - and the ones on the ADA's (on mine at least) do not lock into place very securely. Also, I don't know how 'clean' they are when they are installed - might be slight corrosion or tarnishing on the contacts.

However, if your sync lights are staying on you're probably ok in that respect.

Wonder if a tiny dab of silicone would be a good idea on those switches. I'm pretty sure mine won't ever do anything other than sync via ADAT.