ADA8000 Hi-End Distortion

[mcpf66]

Hi,

So to get those few extra drum tracks, I have an ADA8000 running through an optical cable into my Black Lion modded Motu 828 MKII. In addition to my regular overheads, I have a couple of SDCs thrown up to capture a little brilliance of the cymbals. Yet whenever the drummer really smacks the cymbals, they distort. It's only the high end that ends up distorting though. Toms running through the ADA8000 are fine. I also noticed a similar annoying/whiney distortion on the high end when I experimented with putting a 57 on a guitar amp through the ADA8000. Because of this, I'm assuming that it's not the microphones.

Is there any stupid thing I'm missing here (like a clock sync) that is causing this to happen? Or is it just the fact that the ADA8000 is (obviously) not top of the line? I haven't read of any similar issues with the ADA8000 having that sort of distortion, so I think I may be missing something very simple.

Thanks!

[Gebo]

Is the sample rate set to match the sample rate on your motu? Ive had my digital pre set wrong and it causes this wierd distortion, and its definitley more prominant in the high end. It could also be your cable.

[mcpf66]

I believe that the sample rates are the same, but I will triple check when I get home. I also think that all the mic cables are fine, but are you referring to a bad ADAT optical cable?

[frans]

Did you remember that the BLA modded 828 wants to be master in your clocking? Soooo... running digital stuff without central clocking can work under certain circumstances (I don't understand it fully but a good driver in your receiving DAW helps and MOTU write good drivers). But it also could be something else.

I had a BLA modded 828 mk1 and a Mackie Onyx800R (8ch via lightpipe/ADAT) unsynced which worked together okay but on some days the top end from all channels in the 800r sounded like sandpaper. I went on to sync the 800R via a Mutec DistributorWS which takes a SPDIF feed from the 828 to generate a clock for the 800R - works like a charm.

I don't understand what happened under the hood, but this got it together. Another piece of gear that would do such a job: a MOTU timpiece old .....and new ($$$).

[Gebo]

Yea, the optical cable could cause something like that I would imagine. Its not likely, but its possible.

[mcpf66]

frans,

that's an interesting point. so, technically if i got a BNC cable and synched up the two machines with the ADA8000 set to slave, do you think this would solve that clock issue? it sounds like the issue you had is similar to my current dilemma.

[mcpf66]

problem solved! thanks everyone

[Spyrow]

did you solve it with the sync?

[loujudson]

Just a question that may help: Do you have enough experience to recognize preamp distortion? You might not want to drive those pres too hard, especially with cymbals and bright guitars... 24 bit give toms of headroom if your gain structure is appropriate.

Try jingling a set of keys in front of the mic and try it at different levels. This is an excellent way to test mic pres, and may show you where to keep the levels. It's basic engineering.

Just a thought. Clock issues usually make pops and clicks, not that kind of distortion, in my experience.

Lou

[mcpf66]

Yes, I do have enough experience to recognize pre-amp distortion. And no, the pres were not even close to being driven hard enough to get any sort of distortion. In addition, like I said earlier, the distortion was a very odd one. Not a nice saturated sound or even a digital clipping. But an odd gritty sound from the high end.

And yes, the word clock synch solved everything! I foolishly forgot to check the back of the ADA8000. After setting it to slave off of the modded 828, we were back in business. Thanks again to everyone for the help.

[frans]

It's always a pleasure to be of help.... with my limited knowledge.