Hi Ken,
I have enjoyed your thoughts on the AES qbox. I was looking at one when they first came out as we were playing with some digital drive. I haven't been doing much in the way of digital interface lately, however I figure the day will come fairly soon when I am. When the day comes I reckon I will be burning the credit card for this very cool toy. A comment on the itech AES input on the Crown Itech amps, the ones that I have used will read 96K on their input, however they will only pass 48K out the loop out. If memory serves me correctly we would only daisy chain like four at a time. In order to feed more amps the signal would hit a DA as soon as it got to the stage.
How does the headphone output sound on the Qbox? Is it very high quality or is it kind of a utility just to be able to hear what is on the line.
How about the onboard speaker? Is it pretty good or similar to the analog Qbox?
Another digital question I have is, how can you tell if you are on the very edge of being a stable signal. Would you have to put the signal on an Oscope? I mean you said it wouldn't lock on a analog cable at 500 feet. What happens if you plugged it in at 300 feet and it locked but it was on the verge of barely working? If it sounded fine on the qbox and through the PA, then I would think it would be fine. I wouldn't want to run the PA on a digital drive without knowing that that it is a very solid lock. If you put the signal on a scope, could you see a square clock signal and be able to see rounded edges when the signal gets a little shaky? This would be useful information to be able to check wordclock cable integrity as well. I haven't had to put a monitor and foh console on the same wordclock yet, but I figure the day is coming. I would definitely want to be able to make sure that I had a good solid clock on that.
Does anybody know of a good book or reference on AES and wordclock distribution? Much as I hate to admit these things are going to affect us all. There are many questions that it would be good to the know the answer to like.
Do you ever need to terminate an AES connection?
How far can you send an AES signal on 110 ohm cable? 500' 1000'?
How far can it reliably travel down an analog snake?
I have also heard that some AES devices output will better than others?
There are similar questions for the wordclock. Imagine if you had FOH and MON both slaved to a masterclock, if that clock isn't completely stable it could nuke everything. It is a very frightening thought. I could see a show with a digital console on both ends of the snake being synced along with a Protools playback system that is interfaced via AES as well. It may not be common right now but we will face it. Whoever it teching something like that in a touring situation better have his stuff together for sure.
Sorry if this got a little off the topic of the Whirlwind device, guess I tangent a lot. If I should post this in the main forum instead I can.
Nicolas