14
U
SING
THE
8824
S
ECTION
6
Overview
This section of the manual discusses some technical issues that you’ll need to be familiar with and a
few applications scenarios. This information may be useful if you want to get everything you can from
the 8824.
Now that you’re familiar with the 8824, use the Fast Setup section of this manual to integrate the unit
into your studio. If you’re using the unit without a host computer, be sure to set the configuration
switches located at the rear of the unit.
Level Setting
Like any A/D converter, the converter’s output represents a fixed window that must properly frame the
audio signal. Set it too low, and lose the signal peaks; set it too high and lose the low-level detail.
In the 16-bit world, when that was all there was for conversion, the placement of the converter win-
dow was more critical due to the larger step size represented by each bit of the digital output. The low
level details in the signal represent things like ambience and soundstage; thus they are critical details.
Capturing these details faithfully means becoming more adept at either setting the window properly or
fitting the signal into the window itself via dynamic range compression.
A 24-bit converter eases this task somewhat. Since the steps are smaller, you now have the option of placing
the audio signal either a bit higher (better resolution for low-level signals, but lower headroom) or lower
(less resolution for low levels, but higher headroom). Of course, if the signal is already recorded, then it’s just
a matter of getting levels set properly and then making the transfer into your workstation.
It’s conceivable that you might want to make a 24-bit recording directly into your workstation. In this
case, set your levels carefully and/or use some preprocessing in the analog domain to make the audio
signal fit into the conversion window.
Clock and Sync Issues
Any time that you have multiple digital audio signals at one time the issue of sync becomes important. Sync
between the signals is important because the converters in the 8824 share a common clock; therefore
external digital signals need to arrive in-sync. This is not a problem if the signals come from a digital multi-
track, however it may be a problem if the signals come from separate sources. In this case, you may need to
provide a sync signal for each of these devices.
It is also possible to sync the 8824’s converters to an external source. You can sync to an external AES/EBU
signal via the 1-2 Digital Inputs or to the Word Clock input. Source selection occurs at the 8824 configura-
tion application. The 8824 does not use the ADAT word clock signal in the ADAT sync connector.
However, it can sync to ADAT signals delivered via the lightpipe connectors.
Note
The word clock output is synchronized to the AES/EBU digital outputs. If the AES/EBU
outputs are fed from the analog inputs, the word clock output gets its signal from the A/D
sync source. If the AES/EBU outputs are fed from the ADAT optical input, the word clock
output gets its signal from that input.
