Z-Systems z-Q2 - Manual (Page 2)

z-q2 Operation
Connect AC power of the proper voltage range with an IEC power cord to the
back of the z-q2. If in doubt, verify the internal power selector switch has been set
to the proper voltage for your country before plugging in power!
System Menu
Dither, Wordlength and Sample Rate Display
Connect the z-q2 to an AES/EBU standard digital audio source whose sample
rate is 32 kHz, 44.1 kHz, 48, 88.2, or 96 Khz. The AES LOCK LED will light to
indicate it’s locked to the incoming signal. Now, press the SYSTEM button once.
You should see this display:
in:1 44k 24 dith
If the system is locked, the sample rate appears in the left side, and the
wordlength and dither mode appears in the middle. As in all z-q2 menus, the labels
appear above the knob which affects the parameter. For example, in this menu, you
can change the wordlength and dither by rotating the middle knob to any of the
following:
24 dith 24 bits 20 dith 20 bits 16 dith 16 bits 16 pwr2 16 pwr3
The last two POW-R dither options are only available at 44.1 or 48 kHz. The
sample rate cannot be altered as the system is always slaved to the incoming rate.
Using the dither and wordlength settings
When the z-q2 equalizer is feeding additional digital processors, nearly always
set the output wordlength to 24 dith. This is the maximum wordlength available
in AES/EBU and will send the highest resolution signal to the following device.
The Dither in the z-q2 is a carefully-randomized floating point dither which
removes quantization distortion. The dither noise level at the 24 dith setting is at
approximately -141 dB below full scale, so we doubt you will consider this to be
an audible problem! (To put this in perspective, most people consider analog tape
hiss below about -80 dB to be inaudible, and the noise floor of the best analog
audio console in the world is around -90 to -100 dB below full scale. Microphone
preamplifiers can do a bit better, but in the real world, noises add, and the practical
full band noise of the quietest typical musical recording is rarely better than about
-70 dBFS, excluding fadeouts).
z-q2 Operations Manual version 1.0 1/2301 Page 2