Crest Audio X-RACK XR-20, X-Rack XR-24 Owner's Manual

owner’s manual

X-Rackrack mount mixers

XR-20
XR-24

Important precautions

XR-20 / XR-24 owner’s manual

Save the carton and packing materials!

1

Should you ever need to ship the unit,
use only the original factory packing.

For replacement packaging, call Crest Audio’s
Customer Service Department directly.

Read all documentation before

2

operating your equipment.Retain all
documentation for future reference.

Follow all instructions printed on

3

unit chassis for proper operation.

Do not use the unit if the electrical

4

power cord is frayed or broken.

The power supply cord should be rout­ed so that it is not likely to be walked on
or pinched by items placed upon or
against it.

Always operate the unit with the

5

AC ground wire connected to the
electrical system ground.Precautions

should be taken so that the means of
grounding of a piece of equipment is not
defeated.

Service Information

Do not open unit!

Opening the unit will expose you to
potentially dangerous voltages. There are
no user serviceable parts inside.

Equipment should be serviced by
qualified service personnel when:

A.The equipment has been exposed to rain.
B.The equipment does not appear to oper-

ate normally, or exhibits a marked change in
performance.

C.The equipment has been dropped, or the

enclosure damaged.

To obtain service:

contact your nearest Crest Audio
Service Center, Distributor, Dealer,
or Crest Audio at 201.909.8700
or visit www.crestaudio.com for addi­tional information.

email techserve

@crestaudio.com

USA

This symbol is used to alert
the operator to follow important
procedures and precautions
detailed in documentation.

This symbol is used to warn opera­tors that uninsulated “dangerous
voltages” are present within the
equipment enclosure that may

pose a risk of electrical shock.

Damage caused by connection to

6

improper AC voltage is not covered
by any warranty.

Do not spill water or other liquids

7

into or on the unit, or operate the
unit while standing in liquid.

The power cord of equipment

8

should be unplugged from the out­let when left unused for a long peri­od of time.

IIMMPPOORRTTAANNTT SSAAFFEETTYY IINNSSTTRRUUCCTTIIOONNSS

WWAARRNNIINNGG::

When using electrical products, basic cautions should always be followed, including the following:

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with a dry cloth.

7. Do not block any of the ventilation openings. Install in accordance with manufacturer’s instructions.

8. Do not install near any heat sources such as radiators, heat registers, stoves or other apparatus (including
amplifiers) that produce heat.

9. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one
wider than the other. A grounding type plug has two blades and a third grounding plug. The wide blade or third
prong is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.

10. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the
point they exit from the apparatus.

11. Only use attachments/accessories provided by the manufacturer.

12. Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer or sold with the apparatus. When
a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.

13. Unplug this apparatus during lightning storms or when unused for long periods of time.

14. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in

any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the
apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

15. Never break off the ground pin. Write for our free booklet “Shock Hazard and Grounding.” Connect only to a power
supply of the type marked on the unit adjacent to the power supply cord.

16. If this product is to be mounted in an equipment rack, rear support should be provided.

17. Exposure to extremely high noise levels may cause a permanent hearing loss. Individuals vary considerably in
susceptibility to noise-induced hearing loss, but nearly everyone will lose some hearing if exposed to sufficiently
intense noise for a sufficient time. The U.S. Government’s Occupational and Health Administration (OSHA) has
specified the following permissible noise level exposures:

Duration Per Day In Hours Sound Level dBA, Slow Response

890
692
495
397
2 100

1 1/2 102

1 105

1/2 110

1/4 or less 115

According to OSHA, any exposure in excess of the above permissible limits could result in some hearing loss. Ear plugs or protectors to the
ear canals or over the ears must be worn when operating this amplification system in order to prevent a permanent hearing loss, if exposure
is in excess of the limits as set forth above. To ensure against potentially dangerous exposure to high sound pressure levels, it is
recommended that all persons exposed to equipment capable of producing high sound pressure levels such as this amplification system be
protected by hearing protectors while this unit is in operation.

SSAAVVEE TTHHEESSEE IINNSSTTRRUUCCTTIIOONNSS!!

4

1

2

3

table of contents

Introduction

Thank you and congratulations on your purchase of your new
Crest Audio X-Rack mixer. We’re confident that you will enjoy
many years of trouble-free service from it. You will quickly find
that it fits into a wide variety of mixing applications with ease.
Due to well thought out sets of features, coupled with intelli­gent circuit design and the highest standards in construction &
workmanship, all Crest Audio console products excel above and
beyond the competitor’s products, in every area.

This owner’s manual covers both the XR-20 and the XR-24 X­Rack mixers. Features are identical for both models, the only dif­ference is the amount of Mono Inputs versus Stereo Inputs. The
XR-20 has 12 Mono inputs and 4 Stereo inputs, adding up to a
total of 20 microphone inputs. The XR-24 has 8 Mono inputs
and 8 Stereo inputs, adding up to a total of 24 microphone
Inputs.

Please read this manual thoroughly and keep it handy for future
reference. If you have any operating concerns that are not cov­ered in this manual, or have application questions of any type,
don’t hesitate to contact Crest Audio directly either by phone,
fax, or email. Here is our technical support contact information:
Phone: [phone]
Fax: [phone]
Email: [e-mail]

Mono Input channels p. 7

Front panel controls and rear panel connections

Stereo Input channels p.17

Front panel controls and rear panel connections

Master section P .27

Aux masters, groups, main outs, monitor section.
Front panel controls and rear panel connectors.

Specifications P. 47

XR-20 / XR-24 owner’s manual

p.4

XR-20/24 block diagram

JIMI

how to use this manual

format

This manual uses a format that is intended to be easy to read, yet technical for those
who need to know all the details. For feature descriptions, this is done by devoting the
left side of each page to 1) an overall module picture, 2) a block diagram, and 3) a con­trol closeup. These images all pertain to the features and control descriptions on the
right side of the page. The intention is to make the manual easy to read while including
all the technical details needed for getting the most out of the X-Rack - a compact, flexi­ble, feature-rich addition to Crest Audio's growing line of audio mixing console products.

conventions

Control Icons

This manual uses symbols to illustrate what the control descriptions are referring to. This
makes it possible to avoid redundant wording and makes the control descriptions clear.

Switch in the UP, non-activated position
Switch in DOWN, activated position

Switch that illuminates when in the DOWN position

Momentary switch that illuminates when activated

LEDthat is on, indicating that it's associated feature is activated

Potentiometer

Standard 1/4" TRSjack (used for line level inputs and insert sends)

1/4" TRSjack with normal switching (used on insert returns)

Female XLRinput jack

Male XLRoutput jack

p.5

Mono input channel

1

XR-20 / XR-24 owner’s manual

Module

Block diagram

+48V ON

BAL MIC IN

+48V

LINE

GAIN

12 - 70 dB

Controls

HPF

70Hz

-18dB/Oct

p.6

BAL LINE IN

27dB

PAD

HPF

INPUT

PREAMP

Mono Input channel

Front panel features

Mono Input channel features are identical for both the XR-20 and the XR-24. The XR-20
has 12 Mono inputs and the XR-24 has 8 Mono inputs.

Line Input (mic pad)

The input preamp circuit is set up to accept a mic-level signal. This signal is
brought in via the XLR mic-input connector located on the rear panel. The 1/4"
TRS input jack is disabled.

The input preamp circuit is set up to accept a line-level signal from either
the XLR mic-input connector or the 1/4" TRS input jack, both located on the rear
panel. Since the sensitivity of the input preamp is reduced, this control can also act
as a PAD for bringing a very hot microphone feed down to a controllable level,
avoiding overload. When a plug is inserted into the 1/4" TRS input jack, the XLR
mic-input connector is disabled.

Gain

The Input gain control is used to establish proper gain structure in the chan­nel. For best results, use the Solo system to monitor the channel while you set
the gain. The goal is maximum gain without distortion. Both the main LED meters
(during Solo) and the channel’s Level/Peak indicator can be used for adjusting gain.

1

70 Hz high-pass filter

The high-pass filter reduces or eliminates unwanted low frequencies without sub­stantially affecting the program material. Quite often such unwanted low frequen­cies are included with mic- or line-input signals. For example, stage rumble or
wind can be picked up through vocal mics. The cut-off frequency of the high-pass
filter is 70 Hz and the slope is -18dB per octave.

HPF

High-pass filter is on.

p.7

Mono input channel

1

XR-20 / XR-24 owner’s manual

Module

Controls

Block diagram

LEVEL

LF LOW MID HI MID HF

p.8

FREQ LEVEL LEVELFREQ LEVEL

EQ ON

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

FOUR BAND EQ

Front panel features
EQ

Many audio signals coming into the console require some degree of corrective eq
in order to be part of a good sounding mix. XR-20 & XR-24 offer a very useful
and great sounding eq section on each channel. The input EQ consists of four
bands: High, High-mid, Low-mid and Low. The High and Low frequency bands each
have a boost/cut control and their frequencies are fixed. The High-mid and Low­mid bands each have variable boost/cut and variable frequency.

high frequency—HF

Boost / Cut15dB boost and cut. Shelving @ 12 kHz

high mid—HM

FrequencyContinuously sweepable between 400 Hz and 8 kHz.
Boost / Cut15dB boost and cut. Bell curve with a Q of 1

Mono Input channel

1

Low mid—LM

FrequencyContinuously sweepable between 100 Hz and 2 kHz.

Boost / Cut15dB boost and cut. Bell curve with a Q of 1

Low frequency—LF

Boost / Cut15dB boost and cut. Shelving @ 80 Hz.

EQ on

Equalizer is on. This switch is used to activate the EQ section and can be

used to make A/B comparisons between "flat" and eq'd signals.

p.9

Mono input channel

MUT

E

1

XR-20 / XR-24 owner’s manual

Module

Controls

Block diagram

PRE

INSERT

PRE

EQ

EQ ON

FADER

PRE-SOURCE

SELECT

HF

12 KHZ

CHAN

FADER

100MM

PRE

FADER AMP

+10

YES

PRE

SOURCE

MUTE ?

NO

PRE-SOURCE

BUFFER

PAN

A1-2
PRE

A3-4
PRE

A5-6
PRE

MONO L-R G1-2

BUS ASSIGN

SWITCHES

PAN

1-2

AUX SENDS

1 THRU 6

LEVEL

1-2

LEV 3

LEV 4

LEV 5

LEV 6

G3-4

A1

A2

A3

A4

A5

A6

p.10

AUX send features

Six auxiliary sends are available for creating individual output mixes. These can be
used to drive effects processors, provide monitor mixes, create broadcast or
alternate sound reinforcement mixes, or for other special requirements.
Note: The default PRE setting for the Auxes is pre-fader, but post-mute,
post-insert, and post eq. Internal settings can be changed so that PREis also pre­eq and pre mute

Aux 1 - 2 PRE

AUX 1/2 stereo pair is post fader
AUX1/2 stereo pair is pre-fader

Aux sends 1 & 2

Auxes 1 and 2 are configured as a stereo pair. The top knob controls the level
and the bottom knob acts as a PANcontrol. This stereo aux send can be used for
any type of stereo feed from the console, such as live two-track recording, stereo
in-ear monitors, alternate stereo feed for broadcast, and stereo signal processors.
Also, by properly using the pan control Auxes 1 and 2 can be used as discrete
mono Aux buses

Mono Input channel

1

Aux 1/2 level Send level for the Aux 1/2 stereo pair
Aux 1/2 PAN Stereo placement for the Aux 1/2 stereo pair

AUX 3-4 PRE

AUX 3 and AUX 4 are post fader
AUX3 and AUX 4 are pre-fader

Aux sends 3, 4, 5 & 6

Auxes 3, 4, 5, & 6 are configured as descrete mono aux sends. They are typically
used to feed signal processors and for on-stage monitors.

Auxes 3, 4, 5, &6 level Set levels Auxes 3, 4, 5, & 6.

AUX 5-6 PRE

AUX 5 and AUX 6 are post fader.
AUX5 and AUX 6 are pre-fader.

p.11

Mono input channel

1

XR-20 / XR-24 owner’s manual

Module

Block diagram

MUTE

TO

PEAK

CIRCUIT

PFL

Controls

SOLO LEFT

SOLO RIGHT

SOLO DC

p.12

EQ ON

RE

Q

PRE-SOURCE

CHAN

FADER

100MM

PRE

FADER

SELECT

FADER AMP

+10

YES

PRE

SOURCE

MUTE ?

NO

PRE-SOURCE

BUFFER

PAN

A1-2
PRE

A3-4
PRE

A5-6
PRE

MONO L-R G1-2

BUS ASSIGN

SWITCHES

PAN

1-2

AUX SENDS

1 THRU 6

LEVEL

1-2

LEV 3

LEV 4

LEV 5

LEV 6

G3-4

A1

A2

A3

A4

A5

A6

Bus assignment features

The bus assignment section offers considerable flexibility for creating what even­tually becomes the main output mix. Two stereo subgroups are available for creat­ing submixes or separate stereo mixes. All assignments are derived post-fader,
post-eq, and post-mute.

PAN control

The pan control positions the signal within the stereo left/right (or
odd/even) field. PAN affects signals that are assigned directly to Left-Right, Groups
1-2 and Groups 3-4

Mono bus assign

The channel is assigned to the MONOmix bus. PANhas no affect on

MONO

L-R bus assign

The channel is assigned to the Left and Right mix buses.

G 1-2 bus assign

The channel is assigned to Groups 1 and 2. Groups 1 and 2 are configured
as a stereo pair. They can also be treated as two discrete mono groups by using
the PAN control.

Mono Input channel

1

G 3-4 bus assign

The channel is assigned Groups 3 and 4. Groups 4 and 4 are configured as a
stereo pair. They can also be treated as two discrete mono groups by using the
PAN control.

Input fader (100mm)

The fader is the primary level control for signals being sent to any of the consoles
post fader mix buses,

MUTE

The input channel is muted and the MUTELEDis alluminated. All AUX
feeds and bus assignments are shut off. Insert send and SOLO signals are still
active.

PK / SIG LED indicator

This two-color(green & red) LED is used to monitor the channel’s signal
level. Signal present (green) is monitored pre-fader. Peak (red) is monitored at the
preamp and before & after the fader.

PFL

PFL -Pre fader listen. This button routes the channel’s signal to the Solo bus
for monitoring through headphones or in the control room. The Peak (red) LED
is illuminated to show PFLstatus.

p.13

Mono input channel

1

Rear panel

Block diagram

BAL MIC IN

LINE

BAL LINE IN

27dB

PAD

GAIN

12 - 70 dB

INPUT

PREAMP

HPF

70Hz

-18dB/Oct

HPF

XR-20 / XR-24 owner’s manual

Connectors

INSERT

SEND / RTN

DIRECT OUT

REAR PANEL

+48V O N

BAL M IC IN

BAL LI NE IN

INSERT

SEND / RT N

DIRECT OUT

REAR PANEL

DIRECT OUT

POST

FADER

SOURCE

GC

PRE

FADER

X-RACK MONO INPUT MODULE

+48V

HPF

GAI N

70Hz

12 - 70 dB

INPUT

PREAM P

DIRECT O UT

SOURCE

-18dB/Oct

HPF

LINE

27d B

PA D

POST

FADER

G C

PRE

FADER

12 OR 8 M O NO I NP UT S A V A IL A B LE

LEVEL

FREQ

LEVEL LEVELFREQ LEVEL

LF LOW MID HI MID HF

FOUR BA ND EQ

INPUT

SIGNA L

LED

PEAK

R

(PFL)

SIG

G

POST

FADER

PRE

FADER

SOLO

TRIGG ER

MUTE

EQ ON

CHAN

FADER

FADER

SELECT

PRE

100MM

FADER A MP

+10

YES

SOURCE

MUT E ?

NO

PRE-SOURCE

BUFFER

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

PRE

EQ

PRE

INSERT

PRE-SOURCE

PAN

PRE

A1-2
PRE

A3-4
PRE

A5-6
PRE

TO

PEAK

CIRCUIT

MONO L-R G1-2

BU S A S SIG N

SW IT CH ES

PAN
1-2

PFL

AUX SENDS

1 THRU 6

LEVEL

LEV 3

LEV 4

LEV 5

LEV 6

SOLO LEF T

SOLO RI GHT

SOLO DC

G3-4

1-2

A1

A2

A3

A4

A5

A6

p.14

Rear panel features

48 V Phantom power

48 volts DC is applied to pins 2 and 3 on the mic-input XLRconnector. This
option is used with condenser microphones and active direct boxes that require
an external DC voltage (phantom power ) in order to operate.

Line INPUTjack

Line-level signals, balanced or unbalanced, may be brought into the
input channel through this jack. The LINE INPUT switch must be pressed for this
jack to be active.

MIC INPUT jack

This balanced female XLR accepts a low-impedance microphone signal, or a
line-level signal, depending on the position of the LINEINPUTswitch on the front
panel.

INSERT jack

This switching 1/4” TRS jack allows an external signal processor to be
inserted into the signal path of the channel. The tip carries the SEND signal and
the ring carries the RETURN signal.

Mono Input channel

1

DIRECTOUT jack

The channel’s signal can be brought out of the console via the direct
out jack. The signal that appears at this jack is normally post fader. There is an
internal option for making it pre fader.

p.15

Stereo input channel

1

XR-20 / XR-24 owner’s manual

Module

Block diagram

+48V ON

BAL MIC IN

+48V

LINE

GAIN

15 - 60 dB

MONO

Controls

BAL

p.16

LEFT

BAL LINE IN

BAL MIC IN

RIGHT

BAL LINE IN

27dB

PAD

27dB

PAD

INPUT

PREAMP

PEAK
(PFL)

PRE

EQ

INPUT

SIGNAL

LED

R

Stereo Input channel

Front panel features

Stereo Input channels features are identical for both the XR-20 and the XR-24. The XR­20 has 4 Stereo inputs, and the XR-24 has and 8 Stereo inputs. On both models the
Stereo inputs are

inputs. They can be treated as mono input channels, or as Stereo input channels.

Stereo Line Input (mic pad)

nals are brought in via the XLR mic-input connectors located on the rear panel.
The 1/4" TRS input jacks are disabled.

either the XLR mic-input connectors or the 1/4" TRS input jacks, all located on
the rear panel. Since the sensitivity of the stereo input preamp is reduced, this
control can also act as a PAD for bringing very hot microphone feeds down to a
safe level, avoiding overload. When a plug is inserted into a 1/4" TRS input jack, the
XLR connector is disabled.

Gain

located to the left of the master section, to the right of the Mono

The stereo input preamp circuit is set up to accept mic-level signals. The sig-

The stereo input preamp circuits are set up to accept line-level signals from

1

The Input gain control is used to establish proper gain structure in the chan­nel. The GAINcontrol affects both the Left and Right input signals. For best
results, use the Solo system to monitor the channel while you set the gain. The
goal is maximum gain without distortion. Both the main LED meters (during Solo)
and the channel’s Level/Peak indicator can be used for adjusting gain.

SUM INPUTS

By summing the inputs, a stereo input channel can be used as a mono input chan­nel.

The channel functions as a stereo input.

If signals are applied to both the Left and Right input jacks, they will be
summed together as a mono signal. If a signal is applied to just one of the input
jacks, it will be treated as a mono signal throughout the rest of the channel.

p.17

Stereo input channel

A

1

XR-20 / XR-24 owner’s manual

Module

Controls

Block diagram

NO

BAL

PRE

EQ

p.18

LEVEL

FREQ LEVEL LEVELFREQ LEVEL

LF LOW MID HI MID HF

FOUR BAND EQ - LEFT

LF LOW MID HI MID HF

FOUR BAND EQ - RIGHT

PRE

FADER

MUTE

EQ ON

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

CHAN

FADER

100MM

F

Front panel features

Stereo EQ

The Stereo Input channel has two parallel EQ circuits that are controlled by the
same set of knobs.

high frequency—HF

Boost / Cut15dB boost and cut. Shelving @ 12 kHz

high mid—HM

FrequencyContinuously sweepable between 400 Hz and 8 kHz.
Boost / Cut15dB boost and cut. Bell curve with a Q of 1

Low mid—LM

FrequencyContinuously sweepable between 100 Hz and 2 kHz.

Stereo Input channel

1

Boost / Cut15dB boost and cut. Bell curve with a Q of 1

Low frequency—LF

Boost / Cut15dB boost and cut. Shelving @ 80 Hz.

EQ on

Equalizer is on. This switch is used to activate the EQ section and can be

used to make A/B comparisons between "flat" and eq'd signals.

p.19

Stereo input channel

2

XR-20 / XR-24 owner’s manual

Module

Block diagram

PRE

FADER

MUTE

TO

PEAK

CIRCUIT

Controls

PFL

SOLO LEFT

SOLO RIGHT

SOLO DC

CHAN

FADER

100MM

ES

PRE

SOURCE

MUTE ?

O

PRE-SOURCE

BUFFERS

LEFT

RIGHT

FADER AMPS

LEFT

+10

+10

RIGHT

POST

FADER

A1-2
PRE

A3-4
PRE

A5-6
PRE

MONO L-R G1-2

LEFT

RIGHT

BUS ASSIGN

SWITCHES

PAN

1-2

L & R

MIXED

L & R

MIXED

LEVEL

1-2

LEV 3

LEV 4

LEV 5

LEV 6

AUX SENDS

1 THRU 6

G3-4

A1

A2

A3

A4

A5

A6

p.20

AUX send features

Six auxiliary sends are available for creating individual output mixes. These can be
used to drive effects processors, provide monitor mixes, create broadcast or
alternate sound reinforcement mixes, or for other special requirements.
Note: The default PRE setting for the Auxes is pre-fader, but post-mute,
post-insert, and post eq. Internal settings changed be changed so that PREis also
pre-eq and pre mute

Aux 1 - 2 PRE

AUX 1/2 stereo pair is post fader

AUX1/2 stereo pair is pre-fader

Aux sends 1 & 2

Auxes 1 and 2 are configured as a stereo pair. If the channel is configured as a
stereo input, the Left and Right signals are routed to Auxes 1 and 2, retaining the
stereo split. The PANknob acts as a balance control. This stereo aux send can be
used for any type of stereo feed from the console, such as live two-track record­ing, stereo in-ear monitors, alternate stereo feed for broadcast, and stereo signal
processors. Also, by using the pan control to select a single bus, Auxes 1 and 2
can be used as discrete mono Aux buses

Stereo Input channel

2

Aux 1/2 level Sets level for the Aux 1/2 stereo pair

Aux 1/2 PAN If the MONOSUM button is up, this knob controls the

stereo balance for Auxes 1 and 2. If the MONO SUM button is down, the
summed signal is panned between Auxes 1 and 2

AUX 3-4 PRE

AUX 3 and AUX 4 are post fader

AUX3 and AUX 4 are pre-fader

Aux sends 3, 4, 5 & 6

Auxes 3, 4, 5, & 6 are configured as descrete mono aux sends. They are typically
used to feed signal processors and for on-stage monitors. Stereo signals are
summed together to make up the source for Auxes 3, 4, 5 & 6.

Auxes 3, 4, 5, & 6 level Set levels Auxes 3, 4, 5, & 6.

AUX 5-6 PRE

AUX 5 and AUX 6 are post fader.

AUX5 and AUX 6 are pre-fader.

p.21

Stereo input channel

2

XR-20 / XR-24 owner’s manual

Module

PRE

FADER

MUTE

CHAN

FADER

100MM

ES

PRE

SOURCE

MUTE ?

O

PRE-SOURCE

BUFFERS

LEFT

RIGHT

FADER AMPS

LEFT

+10

+10

RIGHT

POST

FADER

A1-2
PRE

A3-4
PRE

A5-6
PRE

TO

PEAK

CIRCUIT

MONO L-R G1-2

PAN

LEFT

RIGHT

PFL

BUS ASSIGN

SWITCHES

1-2

L & R

MIXED

L & R

MIXED

G3-4

LEVEL

1-2

LEV 3

LEV 4

LEV 5

LEV 6

AUX SENDS

1 THRU 6

Controls

SOLO LEFT

SOLO RIGHT

SOLO DC

A1

A2

A3

A4

A5

A6

p.22

Bus assignment features

The bus assignment section offers considerable flexibility for creating what even­tually becomes the main output mix. Two stereo subgroups are available for creat­ing submixes or separate stereo mixes. When the channel is being used as a
stereo input, Left/Right, Groups 1 & 2 Groups 3/4 bus assignments are configured
as true stereo pairs. Bus assignments are derived post-fader, post-eq, and post­mute.

BAL control

The balance control adjusts the stereo balance for the Group and Left/Right

assignments.

Mono bus assign

The channel is assigned to the MONOmix bus. The Left and Right signals a

are summed to make up the MONO signal. BAL has no affect on MONO

L-R bus assign

The channel is assigned to the Left and Right mix buses.

G 1-2 bus assign

The channel is assigned Sub Groups 1 and 2. Groups 1 and 2 are configured
as a stereo pair. They can also be treated as two discrete mono groups by using
the BAL control as an GROUP 1/2 mix control.

Stereo Input channel

2

G 3-4 bus assign

The channel is assigned Sub Groups 3 and 4. Groups 4 and 4 are configured
as a stereo pair. They can also be treated as two discrete mono groups by using
the BAL control as an GROUP 3/4 mix control.

Input fader

The fader is the primary level control for signals being sent to any of the consoles
mix buses, The signals affected are the AUX sends selected to be post-fader and
the Mono, L/R, and Groups 1-4.

MUTE

The input channel is muted and the MUTELEDis alluminated. All AUX

feeds and bus assignments are shut off. SOLO is still active.

PK / SIG LED indicator

This two-color(green & red) LED is used to monitor both the channel’s Left
and Right signal levels. Signal present (green) is monitored pre-fader. Peak (red ) is
monitored at the preamp and both before & after the fader.

PFL

PFL -Pre fader listen. This button routes the channel’s signal to the PFL bus
for monitoring through headphones or in the control room. The Peak (red) LED
is illuminated to show PFLstatus.Since the SOLO bus is stereo, stereo image is
preserved.

p.23

Stereo input channel

D

D

2

XR-20 / XR-24 owner’s manual

Rear panel

Block diagram

BAL MIC IN

LEFT

BAL LINE IN

BAL MIC IN

RIGHT

BAL LINE IN

27dB

PAD

27dB

PAD

LINE

GAIN

15 - 60 dB

INPUT

PREAMP

MONO

BAL

PEAK
(PFL)

INPUT

SIGNAL

LED

R

PRE

EQ

LEVEL

FREQ

LF LOW MID

80 - 2 KHZ80 HZ

FOUR BAN

LF LOW MID

80 - 2 KHZ80 HZ

FOUR BAN

SOLO

TRIGGER

PRE-AMP

OUT

L & R

Connectors

LEVEL

REAR P ANEL

+48V ON

BAL MI C IN

BAL LINE IN

BAL MI C IN

RIGHT

BAL LINE IN

REAR PANEL

p.24

LEFT

+48V

27dB

PAD

27dB

PAD

SIG

G

POST

X-RACK STEREO INPUT MODULE

4 OR 8 STEREO INPUTS AVAILABLE

PRE

FADER

POST

FADER

PEAK

CIRCUIT

A1-2
PRE

LEFT

RIGHT

A3-4
PRE

A5-6
PRE

GAIN

MONO

LINE

15 - 60 dB

INPUT

PREAMP

BAL

PRE

EQ

INPUT

SIGNAL

LED

R

PEAK
(PFL)

SIG

G

LEVEL

FREQ

LEVEL LEVELFREQ LEVEL

LF LOW M ID HI M ID HF

FOUR BAND EQ - LEFT

LF LOW M ID HI M ID HF

FOUR BAND EQ - RIGHT

SOLO

TRIGGER

PRE-AMP

OUT

L & R

POST

FADER

L & R

PRE

FADER

L & R

LEFT

RIGHT

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ

PRE

FADER

PRE

EQ

PRE

FADER

PRE

EQ

EQ ON

PRE-SOURCE

SELECT

YES

NO

CHAN

FADER

100MM

SOURCE

MUTE

PRE

MUTE ?

LEFT

PRE-SOURCE

BUFFERS

RIGHT

FADER AMPS

LEFT

+10

+10

RIGHT

TO

MONO L-R G1-2

BUS ASSIGN

PAN

1-2

L & R

MIXED

L & R

MIXED

PFL

SWITCHES

AUX S EN DS

1 THRU 6

LEVEL

1-2

LEV 3

LEV 4

LEV 5

LEV 6

SOLO LEFT

SOLO RIGHT

SOLO DC

G3-4

A1

A2

A3

A4

A5

A6

Rear panel features

48 V Phantom power

48 volts DC is applied to pins 2 and 3 on the mic-input XLRconnectors.
This option is used with condenser microphones and active direct boxes that
require an external DC voltage (phantom power ) in order to operate.

Line INPUTjacks - Left and Right

Line-level signals, balanced or unbalanced, may be brought into the
input channel through this jack. The LINE INPUT switch must be pressed for
these jack to be active.

MIC INPUT jack - Left and Right

These balanced female XLRs accept low-impedance microphone signals, or
line-level signals, depending on the position of the LINEINPUTswitch on the
front panel.

Stereo Input channel

2

p.25

Master section

3

XR-20 / XR-24 owner’s manual

Module

Block diagram

LED

METERS

FOLLOW SOLO,

NORMALLY SHOW

LEFT OU T

RIGHT OU T

SOLO FEED

L - R

SOLO CT RL

AUDIO SOURCES FOR MONITOR - ALL PRE-FADER

GR P3-4

L / R OUT

+9

6
3
0

-3
6
9

12
15
18
21
24

SOLOONPWR

TAPE INAUX1-2MONOL - RG RP1-2

ON

SOLO OFF

LEFT

PRE-FADER

ADD

MONO
RIGHT

PRE-FADER

MO NIT OR

LEVEL

SUM

MONO

L

R

Controls

ALT

LEVEL

GCGC

GCGC

TO

PH O NE S

M O N- L
M O N- R

OUT

ALT

p.26

TAPE IN

L

TAPE IN

R

TAPE-IN L

TAPE-IN R

TAPE-IN

TO :

PHO NES

&

MONITOR

MONO OU T
MONO PRE

LEVEL

MO NIT OR SO UR CE SELECT

( SELECTED SOURCE S ADD TO GETHER )

TAPE TO

AUX 1-2

LE FT B US

RI GHT BUS

TAPE TO

L/R

ADD

MONO

(RECESSED)

LEFT OU T

RIGHT OU T

TAPE-IN R

TO

ALT -OU T

TAPE-IN L

A UX - 1 BUS
A UX - 2 BUS

TAPE

IN

SOLO FEED

L - R

SOLO CTRL

MONITOR

MON-L

MON-R

SOLO FEED

SOLO CTRL

FRO M

L - R

SOLO DC

SOLO LEFT

SOLO RIGHT

SO LO
CO NTR O L
LO G IC

SOLO

OFF

L

R

HEADPHONE

L

R

MIX AMPS

LEVEL

SOLO

HEADPHONE

AMPS

SOLO

FEED

L - R

SOLO

CTRL

TO:
PHONES,
MO NIT OR

&

MET ERS

GCGC

MONITO R

GCGC

OUT

Master section

Front panel features

The XR-20 & XR-24 have a comprehensive output section, including meters, master
level controls, and a flexable group assignment section.

Headphone control section

In normal use, the headphone out is used to monitor the Solo system. The Solo
system is made up of anything that is PFL’d (pre-fader-listen) or AFL’s (after fader
listen).

The hirarchy of what appears in the headphones when nothing is soloed, or when
the SOLOOFFbutton is pressed is as follows:

MONITOR when FROMMONITORis engaged.
TAPEINwhenTAPEINis engaged and FROMMONITORis not engaged.
LEFTand RIGHTmasters when neither FROMMONITORnor TAPEIN
are engaged.

3

MONO OUT
MONO PRE

ADD

MONO

(RECESSED)

LEFT OUT

RIGHT OUT

TO

ALT-OUT

TAPE-IN L

TAPE-IN R

TAPE

IN

MON-L

MON-R

FROM

MONITOR

SOLO FEED

L - R

SOLO CTRL

SOLO

OFF

HEADPHONE

LEVEL

L

R

HEADPHONE

AMPS

Headphone jack

This 1/4” TRS jack is intended for stereo headphones. It can also be
used as a stereo control-monitor output from the mixer. From this jack you can
get a number of signals, including SOLO, Left, Right & Mono, and Monitor / Tape
feeds.

Headphone level

This knob controls the level that appears at the Headphone Jack.

SOLO OFF

Solo (PFLor AFL) overrides the default headphone signals unless this button is
depressed.

Whenever something is Soloed, it appears in the headphones.
Soloed signals do not appear in the headphones.

p.27

Master section

3

Module

XR-20 / XR-24 owner’s manual

Controls

Block diagram

TAPE-IN L

TAPE IN

L

TAPE-IN R

TAPE IN

R

TAPE-IN

TO :

PHO NES

MONITOR

MONO OU T
MONO PRE

LED

METERS

FOLLOW SOLO,

NORMALLY SHOW

LE FT B US

RI GHT BUS

TAPE-IN L

TAPE-IN R

L / R OUT

A UX - 1 BUS
A UX - 2 BUS

TAPE

IN

LEFT OU T

RIGHT OU T

SOLO FEED

L - R

SOLO CT RL

AUDIO SOURCES FOR MONITOR - ALL PRE-FADER

GR P3-4

MO NIT OR SO UR CE SELECT

( SELECTED SOURCE S ADD TO GETHER )

TAPE TO

AUX 1-2

LEVEL

TAPE TO

L/R

&

ADD

MONO

(RECESSED)

LEFT OU T

RIGHT OU T

TO

ALT -OU T

SOLOONPWR

SOLO FEED

L - R

SOLO CTRL

MONITOR

MON-L

MON-R

SOLO FEED

SOLO CTRL

FRO M

L - R

+9

12
15
18
21
24

TAPE INAUX1-2MONOL - RG RP1-2

6
3
0

-3
6
9

SOLO DC

ON

SOLO RIGHT

SOLO OFF

SOLO LEFT

SO LO
CO NTR O L
LO G IC

SOLO

OFF

LEFT

PRE-FADER

ADD

MONO
RIGHT

PRE-FADER

L

R

HEADPHONE

L

R

MO NIT OR

MIX AMPS

LEVEL

LEVEL

SOLO

HEADPHONE

AMPS

MONO

SOLO
FEED

L - R

SOLO
CTRL

SUM

ALT

LEVEL

TO

PH O NE S

M O N- L

M O N- R

GCGC

ALT

OUT

GCGC

L

R

GCGC

MONITO R

OUT

TO:
PHONES,
MO NIT OR

&

MET ERS

GCGC

p.28

Front panel features

FROMMONITOR

The post-level control MONITORoutput becomes the signal in the head­phones when nothing is soloed. This overrides TAPEINif the TAPEINbutton is
depressed.

TAPEIN

The TAPEINsignals appear in the headphones when the FROMMONITOR
button is not depressed and nothing is Soloed.

ADD MONO to Phones and ALTOUT

Mono, or Center can be added when the LEFT and RIGHT masters are present
at the Phone out, on the front panel and the ALTOUTjacks on the rear panel.
The switch is recessed to prevent it’s state from acidentaly being switched.

The default signal at the Headphone output and the ALTOUTjacks is the
stereo LEFT/RIGHT mix.

In addition to the LEFT/RIGHTmix at he the Headphone output and the
ALTOUTjacks, the MONOmaster signal is blended in.

12 V Lamp jack

A BNCjack is used for hooking up a goose-neck lamp. The center connection is
12 Volts DCand the outer connection is ground. A medium or high-intensity 12V
DC Littlite is can be used.

Master section

3

LEDmeters - Left and Right

A pair of LED arrays are provided for monitoring the output levels. They fol­low the SOLO system, making it easy to adjust input and output levels by PFL’ing
and AFL’ing different sources. They normally show the LEFTand RIGHToutput
levels. When something is Soloed, it replaces LEFTandRIGHTon the meters.

SOLO LED

This red LED lights up when anything on the mixer is soloed.

PWRLED

This green LEDilluminates to indicate that the mixer is powered up and

ready for use.

p.29

Master section

UAU

3

Module

Block diagram

XR-20 / XR-24 owner’s manual

Controls

TAPE IN

L

TAPE IN

R

SOLO LEFT

SOLO RIGHT

SOLO DC

TAPE-IN L

TAPE-IN R

AF L

AUX

MIX AMPS

TAPE-IN

LEVEL

TO:

PHONES

&

MONITOR

TAPE TO

TAPE TO

ADD

MONO

(RECESSED)

AUX 1-2

MASTER

+10

+10

AUX 1-2

LEFT BUS

RIGHT BUS

L/R

LEFT OUT

TAPE-IN L

X-RACK AUX BUSES 1-2

(STEREO PAIR )

A

AUX 1

INSERT

SEND / RTN

AUX 1

GC

OU T

GC

AUX 2

OU T

AUX 2

AUX

MIX AMP

SOLO LEFT

SOLO RIGHT

SOLO DC

AF L

p.30

X-RACK AUX BUSES 3 THRU 6

(1 OF 4 SHOWN )

AUX

MASTER

+10

INSER T

SEND / RTN

AUX

GC

OUT

Front panel features

TAPEIN level

On the rear panel there are Left and Right TAPEINconnectors, both 1/4”
TRSand RCA. They can be used to bring in a stereo source such as a two-track
playback from tape, CD, MD, or a sampler. This knob controls the level to the Aux
1/2 and Left/Right buses.

TAPEIN assignment

TOA1-2This assigns the stereo TAPEINto Auxes 1 and 2, which are con-

figured as a stereo pair. This is useful for stereo program monitoring.

TOL-RThis assigns the stereo TAPEINfeed to the Left and Right mix
buses. This is useful for in-between-set background music and as an extra stereo
return.

AUXOUT1-2 level control

This is the master stereo output level control for the AUX 1/2 pair.

Aux 1-2 AFL

Master section

3

This button assigns the AUX 1/2 stereo pair to the solo system. Since it is
AFL, the signal is monitored after the AUXinsert and master level control. Auxes
1 & 2 show up in stereo in the System - 1 on the left and 2 on the right.

AUX OUT 3, 4, 5 & 6 level controls

These are the master output level controls for Auxes 3, 4, 5 &6.

Aux 3, 4, 5, & 6 AFL

These buttons assign Auxes 3, 4, 5 & 6 to the solo system. Since they are
AFL, the signals are monitored after the AUXinserts and master level controls.

p.31

Master section

3

Module

XR-20 / XR-24 owner’s manual

Controls

Block diagram

GROUP

MIX AMP

MONO LEFT

GROUP-TO-MAIN

ODD GROUPS FEED
LEFT SOLO, EVENS

FEED RIGHT SOLO

SOLO LEFT

SOLO RIGHT

SOLO DC

p.32

ASSIGN

SWITCHES

RIGHT

AFL

PEAK

(AFL)

SIG

GROUP

LED

R

G

X-RACK GROUPS

(1 OF 4 SHOWN)

PRE

FADER

POST

FADER

INSERT

SEND / RTN

GROUP

FADER

+10

60MM

TO GROUP

MIX-AMP

GC

GC

GROUP

BUS IN

GROUP

OUT

Front panel features

GROUPassignment section

The XR-20 offers a flexible group assignment arrangement. Each of the four
Groups can be assigned to Left, Right and Mono busses, in any combination.

M - Mono assignments for Groups 1, 2, 3 & 4

Each of the four groups has a Mono assignment button for

routing its post-fader signal to the Mono mix bus.

L - Left assignments for Groups 1, 2, 3 & 4

Each of the four groups has a Left assignment button for

routing its post-fader signal to the Left mix bus.

R - Right assignments for Groups 1, 2, 3 & 4

Each of the four groups has a Right assignment button for

routing its post-fader signal to the Right mix bus.

Group Master Faders 1, 2, 3 & 4

Each Group has a master fader for adjusting its overall level. These signals show
up at the Group OUTjacks on the rear panel and can be assigned to the Left,
Right and Mono buses. They also feed the Solo system when the Group AFL but­tons are down.

Master section

3

GroupPK / SIG LED indicators

These two-color(green & red) LEDs are used to monitor
each of the group’s signal levels. Signal present (green) is monitored pre-fader. Peak
(red ) is monitored at the preamp and both before & after the fader.

AFL buttons for Groups 1, 2, 3 & 4

Each of the four groups has an AFLbutton for monitoring
through the SOLO system. The signal assigned to the Solo bus is picked up after
the fader. The groups show up in stereo in the Solo system - odd - left, even ­right. The Peak (red) LEDs are illuminated to show AFLstatus.

p.33

Master section

3

Module

XR-20 / XR-24 owner’s manual

Controls

Block diagram

AUDIO SOURCES FOR MONITOR - ALL PRE-FADER

GRP3-4

MONITOR SOURCE SELECT

( SELECTED SOURCES ADD TOGETHER )

SOLO FEED

L - R

SOLO CTRL

TAPE INAUX1 -2MONOL - RGRP1-2

SOLO OFF

TO

SUM

MONO

PHONES

MON- L
MON- R

GCGC

MONITOR

OUT

GCGC

MONITOR

LEVEL

L

R

p.34

Front panel features

MONITOROutput section

The XR-20 and XR-24 offer an extensive monitoring system which can be used
for several alternate mix and remote listening purposes. The main L/R & M mixes,
the Groups, Auxes 1&2, the Tape IN, and the Solo system can all be routed to the
Monitor outs. Like the Headphone section, the SOLO system is automatically
routed to the Monitors. This can be defeated by pressing the SOLOOFFbutton.

MONITORLevel control

This knob controls the signal level that appears at the Monitor output on
the rear panel. This signal can also be assigned to the headphone system by press­ing the FROM MONITORbutton located below the Headphone level control.

SUM MONO

The MONITORSystem operates in stereo, and has Left and Right outputs. You
can assign several stereo sources to the Monitor bus,including the Aux 1/2 stereo
pair, the Left/Right busses, the TAPEIN, and the Groups,in stereo odd/even pairs.

The MONITORsystem operates in stereo. . Any stereo signals that are

assigned to the Monitor system remain stereo.

Master section

3

The MONITORsystem operates in mono. Any stereo signals that are

assigned to the Monitor system are summed together.

SOLO OFF

Like the Headphone section, the Solo system is automatically routed to the moni­tors.

.Solo takes overrides anything that is assigned to the monitors.

The Solo system does not appear in the monitors.

Note

If you are 1) routing the Monitor outs to the Headphone system by pressing the
FROMMONITOR button in the Headphone section, and, 2) you don’t want the
Solo system to show up in the headphones, you must press both SOLO OFFbut­tons -the one in the Headphone section andthe one in the Monitor section.

p.35

Master section

3

XR-20 / XR-24 owner’s manual

Module

Controls

Block diagram

AUDIO SOURCES FOR MONITOR - ALL PRE-FADER

GRP3-4

MONITOR SOURCE SELECT

( SELECTED SOURCES ADD TOGETHER )

SOLO FEED

L - R

SOLO CTRL

TAPE INAUX1 -2MONOL - RGRP1-2

SOLO OFF

TO

SUM

MONO

PHONES

MON- L
MON- R

GCGC

MONITOR

OUT

GCGC

MONITOR

LEVEL

L

R

p.36

Front panel features

MONITOROutput section

SOURCESELECT

The Source select portion of the Monitor system allows you do assign the prima­ry mix buses to the Monitor outputs. All assignments are post insert, pre-fader. All
selected sources are added (summed) together.

TAPEIN

Assigns the TAPEINL & R signals to the monitors. The TAPEINjacks are
located on the rear panel. 1/4” TRSjacks and RCAphone plugs are provided for
easy hookup.

A1-2 (Aux 1 & 2)

Assigns Auxes 1 and 2 to the Monitor outputs. Auxes 1 and 2 are config­ured as one stereo Aux bus (see Mono input channel description). 1 is Left and 2
is Right.

MONO

Master section

3

Assigns the Mono bus to both the Left and Right Monitor outs.

L-R (Left & Right)

Assigns the Left and Right buses to the Left and Right Monitor outs.

G1-2 (Groups 1 & 2)

Assigns Groups 1 and 2 to the Monitor outs.1 is Left and 2 is Right

G3-4 (Groups 2 & 4)

Assigns Groups 3 and 4 to the Monitor outs. 3 is Left and 4 is Right.

p.37

Master section

3

Module

Block diagram

LEFT

MIX AMP

RIGHT

MIX AMP

MONO

MIX AMP

AFL

SOLO LEFT

SOLO RIGHT

SOLO DC

XR-20 / XR-24 owner’s manual

Controls

X-RACK MA IN OUT

LEFT-RIGHT

L-PRE

LEFT

RIGHT
BUS IN

MONO

SIGNAL

LED

PEAK
(AFL)

SIG

X-RACK MA IN OUT

R

G

FADER

R-PRE
FADER

MONO

M-PRE
FADER

FADER

100MM

FADER

100MM

FADER

100MM

L-POST

FADER

+10

RIGHT

MONO

R-POST

FADER

+10

M-POST

FADER

+10

L / R

SIGNAL

LED

R

PEAK

SIG

G

LEFT

BUS IN

MONO

BUS IN

MIC LEVEL

30dB
PAD

MIC LEVEL

30dB
PAD

MIC LEVEL

30dB
PAD

L-INSERT

SEND / RTN

BAL OUT

R-INSERT

SEND / RTN

BAL OUT

M-INSERT

SEND / RTN

BAL OUT

LEFT

RIGHT

MONO

p.38

Front panel features

Mono PK/SIGLED

Green/Red - Flashes to indicate the Mono master level. Green during nor-

mal operation and red to indicate overload either at the mix amp or at the fader.

Left/Right PK/SIGLED

Green/Red - Flashes to indicate the summed Left/Right master levels. Green
during normal operation and red to indicate overload either at the mix amps or
at the faders.

MONO AFL

Assigns the post-fader Mono master signal to Solo bus, and illuminates the

Peak (red) LED.

MONO, LEFT& RIGHT Master faders (100mm)

These are the master level controls for the main Left, Right and Mono outputs.

ALTOUT (L-R)

Master section

3

Sets the level for the Alternate Left & Right outputs. These outputs are
made up of the pre-fader Left/Right mix. If the ADD MONO TO PHONES & ALT
OUT button is depressed, the pre-fader MONOmix becomes part of the ALT
OUT as well. Jacks are located on the rear panel. 1/4” TRS and RCAjacks are
provided for easy hookup.

p.39

Master section

3

XR-20 / XR-24 owner’s manual

Rear panel

Connectors

Block diagram

SOLO LEFT

SOLO RIGHT

SOLO DC

AFL

LEFT

MIX AMP

RIGHT

MIX AMP

MONO

MIX AMP

LEFT

BUS IN

MONO
BUS IN

PEAK

SIG

L / R

SIGNAL

LED

R

G

PEAK
(AFL)

SIG

X-RACK MAIN OUT

RIGHT

BUS IN

X-RACK MAIN OUT

MONO

SIGNAL

LED

R

G

LEFT-RIGHT

L-PRE

FADER

R-PRE
FADER

MONO

M-PRE
FADER

LEFT

FADER

100MM

RIGHT

FADER

100MM

MONO

FADER

100MM

L-INSERT

SEND / RTN

MIC LEVEL

L-POST

+10

+10

+10

FADER

R-POST

FADER

M-POST

FADER

MIC LEVEL

MIC LEVEL

30dB

PAD

30dB

PAD

30dB

PAD

LEFT

BAL OUT

R-INSERT

SEND / RTN

RIGHT

BAL OUT

M-INSERT

SEND / RTN

MONO

BAL OUT

p.40

Rear panel features

Left, Right and Mono bus inputs

These three female XLR’s are used to bring external signals directly into the

Left, Right and Mono mix buses. This is useful for linking multiple mixers together.

Group 1, 2, 3 & 4 bus inputs

These 1/4” TRSjacks are used to bring external signals directly into

the first four sub groups. This is useful for linking multiple mixers together.

Master section

3

p.41

Master section

3

Rear panel

Block diagram

GROUP

MIX AMP

MONO LEFT

GROUP-TO-MAIN

ODD GROUPS FEED

LEFT SOLO, EVENS
FEED RIGHT SOLO

SOLO LEFT

SOLO RIGHT

SOLO DC

ASSIGN

SWITCHES

RIGHT

AFL

PEAK
(AFL)

SIG

GROUP

LED

R

G

X-RACK GROUPS

(1 OF 4 SHOWN)

PRE

FADER

POST

FADER

XR-20 / XR-24 owner’s manual

INSERT

SEND / RTN

GROUP
FADER

+10

60MM

TO GROUP

MIX-AMP

GC

GC

GROUP

BUS IN

GROUP

OUT

AUX

MIX AMPS

SOLO LEFT

SOLO RIGHT

SOLO DC

SOLO LEFT

SOLO RIGHT

SOLO DC

AFL

AUX

MIX AMP

AFL

+10

+10

p.42

X-RACK AUX BUSES 1-2

(STEREO PAIR)

AUX 1-2

MASTER

GC

X-RACK AUX BUSES 3 THRU 6

(1 OF 4 SHOWN)

AUX

MASTER

+10

AUX 1

OUT

AUX 1

INSERT

SEND / RTN

GC

GC

AUX 2

OUT

AUX 2

SEND / RTN

INSERT

AUX
OUT

Rear panel features

AUX Inserts 1 through 6

The Aux masters have pre-fader inserts for patching in signal proces­sors. This is useful when using Aux outputs for stage monitors. Tip is Send and
Ring is Return.

Aux OUTTRS Jacks 1 through 6

The six post-fader Aux master outputs are available at these 1/4” TRS
jacks.

Aux OUTXLR’s 1 through 6

The six post-fader Aux master outputs are also available at these male XLR

jacks. (pin 2 hot)

Group Inserts 1 through 4

The Groups have pre-fader inserts for patching in signal processors.
This is useful when using Group outputs for recording or stage monitors. Tip is
Send and Ring is Return.

Tape (line) in

Master section

3

The Left and Right Tape inputs are available as both 1/4” TRSand
RCA.

Alt Out

The Left and Right Alternate outputs are available as both 1/4” TRS
and RCA.

Monitor out

The Left and Right Monitor outputs are available as both 1/4” TRSand
RCA.

Left, Right and Mono Main Inserts

The Left, Right and Mono buses have pre-fader inserts for patching in

signal processors. Tip is Send and Ring is Return.

Left, Right and Mono main Outputs

The Left, Right and Mono post-fader signals appear at these male XLR’s.

Mic/Line Switches for Left, Right and Mono main outputs

These switch are recessed to prevent the from accidentally being hit

Output levels are presented at line level for feeding the line inputs on a sig-

nal processor, another mixer, or a power amplifier.

Output levels are reduced to mic level for feeding the Microphone inputs
on a signal processor or another mixer. Outputs are protected against phantom
power.

p.43

Master section

3

XR-20 / XR-24 owner’s manual

ON

P
O

W

E

R

AC IN

100-240V

50/ 60 Hz

80W

X-RACK REAR PANEL:

AC INLET & SWITCH

Use 5-Pin DIN cable to

interconnect two Consoles

IN OUT

SOLO-LINK CONNECTORS.

USE 5-PIN DIN CABLE FROM

SLAVE CONSOLE OUT

TO MASTER CONSOLE IN

SAFETY

GROUND

SOLO-LINK:

TIES SOLO AUDIO AND

SOLO

LINK

CONTROL BETWEEN

CONSOLES. SLAVE SOLOS

SHOW UP ON MASTER

CONSOLE.

UNIVERSAL INPUT-VOLTAGE
SWITCHING POWER SUPPLY

INTERNALLY FUSED AND

SHORT-CIRCUIT PROTECTED

CHASSIS

GROUND

POLY

FUSES

SHORT-CIRCUIT

PROTECTION

ANALOG
GROUND

AUX DC

GROUND

+17V

-17V

+48V

+12V

BNC CONNECTOR

FOR 12VOLT LAMP

( ON FRONT PANEL )

TO POWER

DISTRIBUTION

RIBBONS

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Rear panel features

Solo Link

When using multiple X-Rack mixers together, the solo systems can be linked.

A 5-pin DINcable is used to link the Solo Audio and control signals.

AC Input

The XR-20 and XR-24 use an internal switching power supply which is capable of
accepting a wide range of line voltages. This industry-standard IECconnector will
mate up with any of the common IECline cords. The in-coming voltage can be
anywhere between 100 and 240 volts, +/- 10%. The AC frequency can be 50 Hz
or 60 Hz.

Master section

3

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Specifications

Specifications

Frequency response +0/-1dB 20Hz-20kHz ref 1kHz

(any input to any output)

THD any output <0.01% THD 20Hz-20kHz@ +15dBu out
Noise mic ein: better than –128dBu 20Hz to 20kHz 150 ohm source, 60dB gain

Bus Noise: better than -85dBu

Crosstalk channel mute >90dB, channel routing >80dB

channel fader attenuation >90dB
aux send attenuation >85dB

Phase Shift < +/- 30 degrees, 20Hz to 20kHz – mic-in to main out
Mic-in XLR 4k ohm balanced

max voltage gain to main outs = 100dB

Line-in XLR and TRS >10k Ohms balanced
RCA tape input >10k Ohms unbalanced
Bus inputs >10k Ohms balanced
L/R/M outputs XLR 100 ohms balanced

(switchable between line or mic level)

Group/direct out TRS 50 ohms ground compensated
Aux outputs XLR & TRS 50 ohms gnd compensated

4

Headphones Stereo, Intended to drive > eight-ohms

Dimensions 17.5" in height (10u) x 19" in width x 4.5" in depth behind panel

Internal Power Supply 100 -240 VAC, 50/60 Hz

Warranty Five Years

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XR-20 / XR-24 owner’s manual
Version 1.0 March 28, 20001

Crest P/N D7000025

Crest Audio

100 Eisenhower Drive

Paramus NJ 07652

[phone]

www.crestaudio.com