z-Qualizer manual
Z-Systems Audio Engineering
5
and equalizer levels are set to 00.0 dB. In the 24 un setting, with everything neutral-
ized, the z-Qualizer is bit-transparent, (
i.e.
, it will pass all incoming AES/EBU signals
without data alteration). In the 20 un (16 un) setting, the z-Qualizer truncates its out-
put to 20 bits (16 bits). These last two settings will rarely be used. Perhaps you wish
to cause some serious digital grittiness (assuming you are fond of the authentic
sound of early digital audio), or you need to truncate the signal because a preceding
device has not done so. Proceed with care when choosing any of the truncation set-
tings; their use is extremely rare.
How to use the POW-r Dither
POW-r dither is a psychoacoustically-optimized dither. The two choices in the z-
Qualizer are POW-r 2 and POW-r 3, at 16 bits only, idealized for CD and DAT re-
cording. POW-r 3 has the strongest noise-shaping, and yields the highest resolution.
We can’t hear the effect of this shaping, but if you feel the shaping of POW-r 3 is too
strong for you, then by all means choose POW-r 2. POW-r 2 may yield slightly less
depth, space and resolution, but the loss is barely perceptible, and much smaller
than with competing noise-shaping processes.
MS encode and decode
This versatile feature can be used in several ways. Let’s return again to the alpha-
numeric display:
24 un
ENC:N
DEC:N
The middle knob changes encode from no to yes, the right hand knob changes MS
decode from no to yes. The MS encoder in the z-Qualizer is located in front of the
gain, left and right channel adjustments and in front of the stereo equalizers. The MS
decoder is located after all processing and before the dither. In the z-Qualizer, the MS
encoder is at unity gain, and the decoder drops the gain by exactly 6 dB, which turns
out to be perfectly symmetrical---but you don’t need to know how the math works to
take advantage of MS mode. If the mode is set to ENC:Y DEC:Y and all equalization
and gains are set to 0 dB, the system remains perfectly bit transparent, since its MS
encoder and decoder are exactly symmetrical, down to the last mathematical bit. You
can leave the system in ENC:Y DEC:Y mode if you wish and operate it as a stereo
equalizer without any concern for losses.
MS
stands for
Mid-Side
, or
Mono-Stereo
. When in MS Y, Y mode, internally the z-
Qualizer becomes an MS-style equalizer instead of a stereo equalizer. However, the
input remains stereo and the output remains stereo. It is useful to know that an MS
encoder contains the same circuit as a decoder. This means that you can use the en-
coder to decode and the decoder to encode if you wish. For example, you could feed
an MS signal into the z-Qualizer, decode it to stereo, manipulate the left and right
balance and eq, and then reencode it to MS for further processing in MS mode.
There are about 16 permutations you could think of, so the limit of flexibility is com-
pletely up to your imagination!
