Z-Systems z-qualizer User Manual

z-Qualizer manual Z-Systems Audio Engineering

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z-Qualizer

MIDI in

MIDI through

z-Qualizer Operations Manual

Welcome!

Congratulations on purchasing the z-Qualizer, the first low-cost outboard digital EQ
capable of world-class mastering performance. The z-Qualizer comes from a distin­guished lineage of mastering processors that Z-Systems has been making for nearly
a decade. You’ve already heard our EQ algorithms on countless recordings and now
you have the chance to hear what they can do for your very own projects.

We urge you to read the following manual before using the z-Qualizer. We’re confi­dent that anyone can learn to use it on their own, but it might be helpful to read the
manual and learn some of the finer points before diving in.

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load

save

m-s & dither

ATTENTION/AVIS:
Risque de choc electronique.
Ne pas ouvrir.

To minimize risk of fire, use only the
specified power adapter.

9V DC

@500 mA

S

MIDI

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S -02.4 2k50 0. 8

gain

AES/EBU

Designed and manufactured in
the US by Z-Systems Audio
Engineering.

Do not open. Risk of electrical
shock. No user-serviceable
parts inside.

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outputinput

Q

signal

1

3

2

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gain

Powering Up

Plug the DC power adapter that was included with the unit into an AC power outlet
and connect the other end of the DC power adapter to the DC power inlet on the back
of the unit. The z-Qualizer will power up quickly. Next, connect the z-Qualizer to an
AES/EBU standard digital audio source. The

signal LED will light to indicate the pres-

ence of a valid incoming signal.

Gain and Channel Offsets

We should mention a general rule at this point. The z-Qualizer is a stereo unit and it
can be operated in either dual-mono or stereo-linked modes. Dual-mono means that
the EQ parameters can be adjusted independently for the left and right channels. In
stereo-linked mode, the left- and right-channel EQ parameters track one another. The
L and R positions on the left knob are used to select between the left- and right-

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z-Qualizer manual Z-Systems Audio Engineering

channel parameter banks, whereas the S position puts the unit into stereo-linked
mode. The left-most edge of the alphanumeric display will always show whether the
unit is in

L, R, or S mode.

When the unit powers up, the left knob will be set to
knob will be set to
right knobs. In this mode, the only parameters showing in the alphanumeric display
will be an
knob indicating, in dBFS, the amount of gain (or attenuation) applied simultaneously
to the left and right channels:

S (indicating the z-Qualizer is stereo-linked) and a number above the gain

gain as indicated by the respective LEDs surrounding the left and

S, for “stereo” and the right

S +00.0

Turning the gain knob adjusts the stereo gain. To apply different gains to the left and
right channels, rotate the left knob to
numeric display changes to show an
mono mode, with the left-channel parameters currently active. Rotating the
changes the left channel gain. The procedure is similar for the right channel. If you
turn the left knob back to
The z-Qualizer is designed so that the left, right, and stereo gains can be different.
This allows you to dial in an offset between the left and right gains and then maintain
that offset by manipulating only the stereo gain.

The equalization in the z-Qualizer is performed with floating-point arithmetic and uses
very special proprietary low-distortion algorithms developed. There are six bands, in­cluding two first-order (6 dB per octave) shelves and four parametrics (bell curves).

S, you’ll see that the stereo gain is still the same as before.

L, for “left channel.” Observe that the alpha-

L indicating that the z-Qualizer is now in dual-

gain knob

Equalization

Stereo-linked mode:
Make sure the left knob is in the S position and turn the right knob to the low shelf

position (one click counter-clockwise from the gain position). The low shelf LED will
light and the alphanumeric display should look like:

S +00.0 1K00

Rotate the gain knob to change the gain of the low frequency shelving equalizer. Ro­tate the
place. This frequency is at the nominal 3 dB point of the curve. The first-order equal­izer is extremely gentle and quite natural-sounding.

Dual-mono mode:
Rotate the left knob to put the z-Qualizer in left-channel mode. The alphanumeric

display now reads:

freq knob to change the frequency below which the shelving action takes

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z-Qualizer manual Z-Systems Audio Engineering

L +00.0 1K00

Here you can display and adjust the left channel shelf independently. Similarly, turn
the left knob to the
reo-linked mode, the
in

S mode. For example, if the L and R gains are different for the low shelving filter, if
you return to stereo-linked mode and adjust the gain, it gets copied to both the
R filters.

Important: You will notice that the “L” indicator in the display is blinking. This is to
remind you that the z-Qualizer is in dual-mono mode. The same is true for the “R”
when you are adjusting the right-channel parameters.

The other bands:
The high-shelf filter is accessed by turning the right knob one click clockwise from the

gain position, and performs exactly as above for stereo-linked or dual-mono equaliza­tion. The

freq knob controls the frequency above which action occurs.

R position and adjust the right channel. If you then return to ste-

L and R filters retain their settings until you change a parameter

L and

The four
Turn the right knob to any of these positions and you will see:

bell-shaped parametrics are numbered as 1, 2, 3, and 4 on the right knob.

S -00.0 1K00 0.4

This indicates, in order, stereo-linked or dual-mono mode, boost/cut, center fre­quency, and quality factor, or Q. As always, the label is above its corresponding knob,
and as above, turning the left knob to
channel separately. Q is the inverse of bandwidth. It is the product of center fre­quency divided by the 3 dB down bandwidth. Thus, a Q of 0.4 produces an extremely
wide curve and will be rarely used. A Q of 0.6 or 0.7 corresponds with the bandwidth
of a typical midrange EQ in an analog equalizer.

Dither
Turn the left knob to m-s & dither, The alphanumeric display will appear as follows:

L and R will allow you to control the left or right

M/S & Dither

24 un ENC:N DEC:N

As in all z-Qualizer 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 left knob to any of the following:

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