Specifications

Synchronization

For proper operation, the entire Delta 66 system is always synchronized to a single

master clock. The master clock is chosen via the Delta Control Panel software and

this clock may be derived from either the Delta 66’s internal crystal oscillators or

S/PDIF In. Most of the time the master clock is taken from the internal crystal

oscillators. However, the S/PDIF option is used in situations where the Delta 66

must be synchronized to external digital audio or sample rates.

As stated, most of the time the master clock is derived from the internal crystal

oscillators. Operation in this mode is similar to that of a generic sound card — for

instance, when a WAV file is played through the Delta drivers, the software

application playing the WAV file is responsible for setting the sample rate in the

sound card hardware. The Delta 66 supports these sample rates by using either of

its internal crystal oscillators and dividing the rate of that oscillator by some value

to derive the proper sample rate.

In situations where S/PDIF In is being used, the Delta 66 should be configured to

get its master clock from the S/PDIF In data stream. The reason for this is

simple — even if the sample rates are set the same, an S/PDIF data stream coming

from an external source is rarely going to be in sync with the Delta 66 (or other

digital audio devices in the system for that matter). If the master clock were set to

use the internal crystal, then the incoming S/PDIF audio would have “pops,”

“crackles,” and other undesirable audio artifacts present in it. Instead, setting the

master clock to “S/PDIF In” will synchronize the Delta 66 to the S/PDIF input data

and its digital audio will be transferred properly.

Finally, the S/PDIF In option may be used to operate the Delta 66 at non-standard

sample rates. When this option is selected, the Delta 66’s sample rate will

automatically match that of the incoming S/PDIF data stream.

NOTE: When the S/PDIF In is selected as the master clock

s o u r ce, the Delta 66 mixer’s frequency response will be

affected by whatever sample rates you inject at the S/PDIF In.

This is because (1) the digital mixer operates at the same

sample rate as the rest of the board, and (2) sample rate and

frequency response are directly correlated.

Using the Delta 66 with your Software Application

Once the Delta 66’s hardware and driver software are properly installed, it is ready

for use with your music application software. Some of these applications may

require you to highlight or enable the Delta 66 drivers within the program, and

others may have a utility that analyzes or profiles the audio cards in your system

and enables the drivers. Your software should have an audio device driver setup

page.

WINDOWS MME AUDIO INPUT DEVICES: All Delta 66 analog and S/PDIF

inputs may be used simultaneously for a total of 6 input channels. Within your