Yamaha Q2031A User Manual [en, de, fr]

YAMAHA

Stereo 31 -Band Graphic Equalizer
Egaliseur Graphique Stereo A31 Gandes
Graphischer 31 -Band-Stereo-Equalizer

QS031A

Operating Manual

Mode d’emploi
Bedienungsanleitung

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You have made the right choice. The YAMAHA Q2031A Graphic Equalizer offers truly
superior price/performance and is fully backed by YAMAHA’s wealth of accumulated
sound expertise. Congratulations and thank you.
The versatile Q2031A enables you to add up to 12dB of boost or cut at any of 31 bands
centered around International Standards Organization (ISO) 1 j3 octave frequencies from
20 Hz to 20 kHz. This versatility opens a wide range of applications in sound reinforce
ment and recording. You can, for example, optimize gain to provide adequate feedback
margins at all frequencies. You can also creatively shape frequency characteristics to
match the particular room, studio, or hall and thus provide the realism and fidelity that

critical audiences demand.

This manual has been written to help you obtain optimum performance and trouble-free

operation from new Q2031A. Please read it throughly.

FEATURES

• This two-channel system offers completely independent
channel control—from the input all the way to the output.

• The narrow, 1/3-octave bandwidth and 31-band control
over the entire 20Hz to 20 kHz range provides very precise
equalization.

• The Q2031A has been very carefully designed from both
functional and operational perspectives. Each of the
equalization sections, for example, has an independent EQ
switch that bypasses the equalizer section, a High-Pass

Filter with a slider-adjustable roll-off frequency, and a

RANGE switch to select boost/cut ±6dB or ±12dB.

• The highly versatile Q2031A can be used in a wide variety
of applications and can be mounted in a standard 19”
rack.

• U.S. & Canadian models

Transformerless balanced (XLR Type connectors) or
unbalanced (1/4” phone jacks) inputs and outputs
are standard, with provisions for both input and

output transformer balancing. Two octal socket
(CHANNEL A and B ) are provided on the rear

panel. They will accept optional bridging input
transformer BRT15K if desired. The output trans
former should be installed by a qualified service

technicians.

CONTENTS

FEATURES .................................................................................. 1

SPECIFICATIONS........................................................................... 2

PRECAUTIONS................................................................................3

FRONT PANEL

REAR PANEL.................................................................................. 5

TYPICAL CONFIGURATIONS ........................................................5

ACOUSTIC CONTROL.....................................................................6

BLOCK DIAGRAM

DIMENSIONS..................................................................................19

................

............................................................... 3

........................................................................

19

SPECIFICATIONS

I

FREQUENCY RESPONSE

TOTAL HARMONIC DISTORTION Less than 0.1% <a> +4dB, 20Hz

HUM & NOISE -96dB (LEVEL Control at

MAXIMUM VOLTAGE GAIN

EQUALIZER CONTROLS

/^Center Frequencies

Variable Range

PEAK LED INDICATORS

0±0.5dB,20Hz~ 20kHz

~20kHz

maximum and all Equalizer­Controls at flat)

+24dB:

Input level sw at —20dB
Output level sw at -l-4dB

31 band (1/3 octave)
20, 25, 31.5, 40, 50, 63, 80,'^

100, 125, 160, 200, 250, 315,

400, 500, 630, 800, Ik, 1.25k,

1.6k, 2k, 2.5k, 3.15k, 4k, 5k,

6.3k, 8k, 10k, 12.5k, 16k,
20kHz
±12dB/±6dB

Light up when the output level
reaches 3dB below clipping.

HIGH PASS FILTER

(Rolloff Frequency)

POWER REQUIREMENTS

U.S. & Canadian models
General model 110/120/220/240V, AC50/60Hz

POWER CONSUMPTION

U.S. & Canadian models
General model

DIMENSIONS (W X H X D)

WEIGHT

12dB/octave
(20Hz ~ 200Hz)

120V,AC60Hz

25W
25W

480 mm x 88 mm x 298 mm
(18-7/8" X 3-1/2" X 11-3/4")

4.8 kg (10.6 lbs.)

INPUT SPECIFICATIONS

INPUT

connertcs

IMPI IT

+4dB

B) _20dB

Input Source

Impedance Impedance

15k ohms

600 ohm

LINES

OUTPUT SPECIFICATIONS

OUTPUT

Connectors

OUTPUT (A, B)

* The input level required to obtain the nominal output level.
* * XL R-type connectors are balanced. Phone jacks are unbalanced.

OdB is referenced to 0.775V RMS.
Specifications subject to change without notice.

OUTPUT

LEVEL
Switch

-4dB

-20dB

Output

Impedance

150 ohms

150 ohms

Impedance

600 ohm Lines

10k ohm Lines

600 ohm Lines

10k ohm Lines

(At Maximum Nniniiicil Coiim-i-fois' ■

+4dB (1.23V) -l-4dB (1.23V)

-20dB (77.5mV)

Load

-20dB (77.5mV)

Nominal Level

-f4dB (1.23V)

-20dB (77.5mV)

Output Level

Clipping

-l-20dB (7.75V)

-4dB (489mV)

Maximum Before

Clipping

H-20dB (7.75V)

H-ISdB (6.16V) Phone Jack

-4dB (489mV)

-6dB (388mV)

XLR-3-31 Type

Phone Jack

Connectors* ‘

XLR-3-32 Type

XLR-3-32 Type

Phone Jack

PRECAUTIONS

• LOCATION

Do not install the Q2031A in location where it might be

subjected to the following;
o Direct sunlight or excessive heat
o Extreme coid
o High humidity or dust
o Strong vibrations

• HANDLING

Do not apply undue force to the switches or controls.

• POWER CORD

Pull the power cord from the wall outlet by the plug only.
Never pull on the cord as this may lead to breaking or
shorting.

FRONT PANEL

• CONNECTIONS

Turn off all equipment power switches before making any

connections. Before moving the Q2031 A, disconnect cords

to other equipment to avoid damaging connectors and
cables.

• CABINET CLEANING AND CARE

Wipe the Q2031A cabinet clean with a soft, dry cloth. Do
not clean it with benzene or other solvents and avoid
spraying insecticides near it.

• LIGHTNING

If your area is prone to lightning strikes, unplug the

Q2031A power cord during storms to prevent lightning

induced transients on the power lines from damaging the
equipment.

O POWER switch

When this switch is pressed to turn power on, the POWER
indicator LED will light. Pressing the switch again turns the

power off.

Q RANGE switches

The RANGE switches select the filter boost or cut range for

the respective channels. When the switches are off, the
normal range of +/—12 dB is selected; when on, the +/—6 dB
range is selected. This latter range is useful for very accurate
equalization. When the Range switch is on, the LED indicator

to its left lights to show that the +/—6dB range is in effect.

0HPF (High Pass Filter) switches

Each channel has an independent HPF switch to switch the
HPF in or out of the audio path before the graphic equal
izer section. With the HPF switch off, the input signal goes
directly to the equalizer, bypassing the HPF.
When the HPF switch is on, the HPF is switched into the
audio path and provides 12 dB per octave rolloff below the

frequency set by the HPF frequency control © . LED in

dicators associated with each switch light when the switch is
on to show that the HPF is being used.

O EQ switch

When the EQ switch, provided for each channel, is off, the

equalizer is bypassed. When the switch is on, its associated

LED indicator lights, and the equalizer is switched into the
audio path. The equalized signal can be compared with the
un-equalized signal simply by alternately turning the EQ
switch on and off.

O level controls

Individual LEVEL controls for both channels adjust the

input sensitivity for optimum input level. When the LEVEL
control is at the top of the scale, the input source signal level
remains unchanged (+4 dB or —20 dB). As the LEVEL
control is moved downward, the input level is reduced.
This control can be used restore the output level when the
overall level has been changed during the equalization process.
This, however, will also change the input level. Equalization
methods which do not change the LEVEL control setting
will yield a better signal-to noise ratio and wider dynamic
range.

O HPF (High Pass Filter) controls

The HPF controls continuously adjust the rolloff frequency
over the entire 20 Hz to 200 Hz range for their associated
HPFs and channels. Below the selected frequency, there will
be a 12 dB per octave rolloff.
The HPF can be adjusted to eliminate low-range standing
waves that sometimes occur in indoor environments, control
vocal “pops” and wind noise in microphones, and reduce
AC hum.

O Equalizer Boost/Cut controls

The 20 Hz to 20 kHz spectrum is divided into thirty-one 1/3
octave bands, each of which has an equalizer boost/cut slider
center (0) detected position. Moving the slider up boosts that

band, moving it down cuts that band.
Convenient scales on either side of the sliders are calibrated
in dB. The H-/—12 dB range is used when the RANGE switch
is off. When the RANGE switch is on, the +/—6 dB range is
used, and the true values are one-half of the calibrated values.

Peak LED indicators on the right of the RANGE switches Q
light when the output level reaches 3dB below clipping. If
the PEAK indicators remain lit, you should reduce the over
all settings of the equalizer sliders.

100 200 500 Ik

FREQUENCY (Hr)

To get the best performance from your 31-band Q2031A
stereo graphic equalizer, it is important that you understand
the frequency components that make up the sounds of each
musical instrument. The following graph is provided to aid

this understanding. You should also bear in mind that
harmonics of fundemental frequencies, plotted as dotted
lines in the graph, can have a significant impact on timbre.

REAR PANEL

O INPUT Connectors

Both balanced (3-pin female XLR type connectors) and un

balanced (1/4” phone jacks) input connectors are available.
A 600 ohm line should be used for both. Use the INPUT
LEVEL switch to set the rated input level to either +4 dB or

-20 dB.

©INPUT LEVEL Switch

Use this switch to set the rated nominal input level to corre
spond to the rated output level of the equipment to be
connected.

0 OUTPUT Connectors

Both balanced (3-pin male XLR type connectors) and un

balanced (1/4” phone jacks) output connectors are available.

A 600 ohm lines should be used for the balanced XLR’s and
a 10k ohm line for the unbalanced 1 /4” phone jacks. Use the
OUTPUT LEVEL switch to set the rated nominal output

level to either +4 or —20 dB.

TYPICAL CONFIGURATIONS

Insertion between the channel (master) insert out/in

MIXING CONSOLE

INSERT OUT

OUTPUT

L R

INSERT IN

©OUTPUT LEVEL Switch

Use this switch to set the rated nominal output level to
correspond to the rated input level of the equipment to be
connected.

U.S. & Canadian models only

©TRANSFORMER In/Out Switch

This switch inserts the optional (See item ©) Input
Transformers into the input stage, bypassing internal
electronic balancing.

©Input Transformer Octal Sockets

Two Octal Sockets are provided to accept optional

15k to 15k ohm bridging Input Transformers. (BRT15K)

©Internal Output Transformer (Optionals)

The Output Transformer should be installed by a quali
fied service technicians.

02031A

CH A INPUT
CH A OUTPUT

Insertion in the main line of the output system

MIXING CONSOLE

OUTPUT L

OUTPUT R

POWER AMPS

Q2031A

CH A
INPUT

CH B
INPUT

CH A

OUTPUT

CH B

OUTPUT

SPEAKERS

POWER AMPS

SPEAKERS