QSC GX7 User manual
TM
GX POWER AMPLIFIER SERIES
User Manual
GX3 300 watts per channel at 8 ohms
GX5 500 watts per channel at 8 ohms
GX7 725 watts per channel at 8 ohms
EN
TD-000271-00 REV. D
*TD-000271-00*
IMPORTANT SAFETY PRECAUTIONS AND EXPLANATION OF SYMBOLS
EN
2
1- Read these instructions.
2- Keep these instructions.
3- Heed all warnings.
4- Follow all instructions.
5- WARNING: To prevent fire or electric shock, do not expose this equipment to rain or moisture. Do not use this apparatus near water.
6- Clean only with a dry cloth.
7- Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8- D
o not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce
heat.
9- The appliance coupler is the AC mains disconnect and should remain readily operable after installation.
10- Do
not defeat the safety purpose of the grounding-type plug. A grounding plug has two blades and a grounding prong. The wide blade
or third prong are provided for your safety. If the provided plug does not fit your outlet, consult an electrician for the replacement of
the obsolete outlet. This apparatus should be connected to a receptacle with a protective earthing (or ground) connection.
11- Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit
from the apparatus.
12- Use only attachments/accessories specified by QSC Audio Products, LLC
13- Use only with hardware, brackets, stands, and components sold with the apparatus or by QSC Audio Products, LLC
14- Unplug the apparatus during lightning storms or when unused for long periods of time.
15- R
efer 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.
!
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance
(servicing) instructions in this manual.
The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated
“dangerous” voltage within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock
to humans.
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER
SERVICING TO QUALIFIED PERSONNEL.
WARNING: To prevent fire or electric shock, do not expose this equipment to rain or moisture.
FCC INTERFERENCE STATEMENT
NOTE: This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to part 15 of the FCC rules. These limits
are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate
radio frequency energy and if not installed and used in accordance to the instructions, may cause harmful interference to radio communications. However,
there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television
reception, which can be determined by switching the equipment off and on, the user is encouraged to try to correct the interference by one or more of the
following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and the receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio or TV technician for help.
© Copyright 2010, QSC Audio Products, LLC
QSC® is a registered trademark of QSC Audio Products, LLC
“QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office
All trademarks are the property of Speakon® and PowerCon® are registered trademarks of Neutrik LLC their respective owners.
3
GX POWER AMPLIFIER SERIES
Professional Power Amplifiers
WELCOME
Thank you for purchasing a QSC Audio amplifier. The GX Series
is the latest in a long line of hard-working, low cost amplifiers,
designed to produce the best possible results for a wide
range of users. In most cases, you can plug and play with no
surprises, but for best results, we recommend you review the
enclosed user guide.
EN
UNPACKING
Confirm that the amplifier has no visible shipping damage.
Confirm that amplifier has the correct AC cord and voltage
rating for your region (See rear panel, Serial Number plate).
It is best to keep the carton in case the amplifier needs to be
returned, at least until it has been tested.
FEATURES
SUPPORT AND SERVICE
Optimized for maximum real-world headroom into 4Ω and 8Ω
speaker systems.
QSC Audio Products maintains a world-wide network of
distributors and service centers. These local agencies will be
able to answer your questions and take care of any problems.
QSC WEBSITE
Our website, www.qscaudio.com, is factory-maintained and
supported in multiple languages. Visit frequently for new
announcements, typical questions, and other user information.
IMPORTANT SAFETY PRECAUTIONS
QSC products are designed for safe operation, and have been
certified by recognized product safety agencies to meet all
normal standards for this type of product. However, dangerous
voltages and power levels exist within the covers of this
amplifier. The user is requested to study the precautions in
this manual. If the product has been dropped, dented, soaked,
or appears to have loose parts inside, the risk of shock is
increased. Unplug the AC cord, and take the product to qualified
service personnel for inspection and repairs.
Power levels matched to the most popular speakers used by
entertainers.
Inputs: XLR, 1/4” TRS and phono input connectors for
compatibility with any source.
utputs: Speakon® combo accepts 1/4” (TS) plugs or
O
Speakon 2-pole and 4-pole plugs (connects 2 poles only).
Binding posts support all other speaker wiring systems.
inimum depth chassis (only 10.1” / 257 mm) fits in
M
compact, inexpensive effects racks.
Light weight – less than 26 lbs (12.5 kg).
Detented gain controls for precise setting and matching of
sensitivity.
GuardRail automatically protects the amplifier and
loudspeakers from damage due to temperature rise or
overdrive without shutting down the show.
Front panel LEDs monitor Power, Signal and Clipping.
POWER RATINGS
Subwoofer / Satellite crossover built-in.
Watts at 0.1% clipping, both channels driven
Model
8 ohms
4 ohms
2 ohms*
GX3
300
425
200
GX5
500
700
350
GX7
725
1000
600
*NOTE: 2-ohm loading is not recommended for high power use.
To avoid protective limiting, use only at low levels.
4
FRONT PANEL FEATURES
MODEL NUMBER
ON-OFF SWITCH
Move the rocker switch up to turn on the amplifier.
The blue PWR LED will turn on immediately.
The red CLIP LEDs may trigger for 1-2 seconds until the amp
has completed its turn-on cycle. If no lights come on, check the
power cord and the AC reset on the rear panel.
COOLING VENTS
The internal fan moves air through the chassis to
reduce temperature rise. Keep vents clear. The fan
speeds up in response to heavy use.
EN
inches (cm)
The GX3, GX5, and GX7
power ratings are shown on
the Specifications page.
5
GAIN CONTROLS, CH1, CH2
The markings show attenuation in dB. For normal
use, keep the control in the upper half of its
range (less than 10 dB of attenuation). If set
below half, the source may overload before
the amplifier reaches full power.
RACK MOUNTING
Fits standard 19-inch rack, 2RU.
Accepts #10 or 6 mm screws,
as determined by the rack rails.
Add rear support to prevent
damage in portable rigs.
EN
RED CLIP LEDS
Red flashing indicates the amp is being overdriven. Heavy overdrive triggers internal
gain reduction, to reduce overload distortion. Normal gain will resume after the signal
level returns to normal. See Troubleshooting if the red LED remains on continuously.
GREEN SIGNAL LEDS
The green LED starts flashing on soft signals (-35 dB), and changes to steady green as
the signal level increases.
BLUE POWER LED
The blue PWR (POWER) LED indicates that the AC switch is on, and the amp is receiving
power. Within two seconds, it is ready to use.
ALTERNATE GAIN MARKING
When the CROSSOVER switch is active (see rear panel),
LF (CH 1) controls low frequencies (subwoofer),
HF (CH 2) controls the high frequencies (mid-high box).
6
REAR PANEL FEATURES
CROSSOVER SWITCH
CROSSOVER POSITION
EXHAUST VENT
Keep vent clear. Install in
open-back rack.
Splits a full-range signal to drive a subwoofer and top box.
CH 1 receives the lows, from 20-100Hz, for the subwoofer.
CH 2 receives 100Hz to 20kHz, to power a full range speaker.
When using CROSSOVER mode, connect signal to CH 1 only.
Use the two Gain controls to balance the LF and HF signals
(see Front Panel).
EN
FULL RANGE POSITION
For normal, 2-channel use with all inputs active.
The crossover is bypassed.
REAR EAR MOUNTING
Rear ears designed for protecting the
rear connector wire dressing and
supporting the amplifier in a rack. A
rear rack support mounting kit (model
FG-000031-00 pack of two) is available
from QSC Technical Services Group.
INPUT CONNECTIONS
BALANCED XLR INPUTS
Pin 2 Positive, Pin 3 Negative, Pin 1 Shield (Ground).
Recommended for long or short runs, either fixed or
frequently changed. Each channel’s XLR and TRS
jacks are connected internally, and provide feed thru
to the other connector.
BALANCED 1/4-INCH TRS INPUTS
Tip positive, Ring Negative, Sleeve Shield (Ground).
Recommended for long or short runs that are
frequently changed.
UNBALANCED 1/4-INCH TS INPUTS
Accepts unbalanced 1/4-inch plugs for short runs.
Tip positive, Sleeve Shield (Ground).
UNBALANCED PHONO INPUTS
Tip Positive, Barrel Shield (Ground). Recommended
for semi-permanent connections to nearby sources,
within the same rack. NOTE: when using these
inputs, the TRS or XLR inputs should not be used.
7
AC BREAKER RESET
If the amplifier shuts off after a long burst of power,
turn off the AC switch and check the circuit breaker.
The button can be pressed back in after a 30 second
cool-down period. If the breaker trips repeatedly,
the amplifier may need servicing.
SERIAL NUMBER AND RATINGS
The rated AC voltage and output power
is shown on the serial number plate.
Record the serial number in a safe place.
EN
AC INLET
SPEAKER CONNECTIONS
BINDING POSTS
Accepts banana plugs
(not permitted in CE regions).
Bare wires or terminals may be
inserted into the side holes.
1/4-INCH CONNECTORS
Insert plug into the center of
the Speakon-Combo jack.
Use only heavy duty speaker cables.
SPEAKON CABLES (2 wire type):
Insert and turn until the connector clicks.
Use the thumb latch or locking ring
to release the plug.
SYSTEM HOOKUP EXAMPLES
EN
8
SYSTEM HOOKUP EXAMPLES
9
EN
10
TROUBLESHOOTING
NO POWER, NO LIGHTS, NO FAN
Confirm that the AC cord is fully seated and connected to a
live outlet. Check the AC source by trying another device
such as a lamp. Check the BREAKER on the back of the
amplifier by pushing in the button. If the breaker trips off
quickly, the amplifier needs servicing.
AMPLIFIER LOSES VOLUME
EN
NO SOUND, WITH BLUE LED ONLY, NO GREEN OR
RED LED
Confirm that the Gain controls are turned up. Confirm that
the input cables are correctly installed at both ends. If using
1/4-inch speaker cables, do not confuse with input cables.
Confirm that the source is active. If necessary, try another
source, or connect another amplifier to the existing source.
If the amplifier is worked too hard, GuardRail™ will
reduce volume to prevent thermal muting. The fan should be
running at full speed. Reduce input signal somewhat and the
amp should return to normal gain within 1-2 minutes. If the
amp feels hot and the fan is not running, it needs to be
serviced.
NO SOUND, BUT THE GREEN LED IS RESPONDING
CHANNEL 1 PRODUCES DEEP BASS ONLY.
The amp mutes briefly when turned on and off to prevent
thumps. If the amp overheats severely, it will mute until it cools
off. The fan will be running at full speed, and sound should
resume in less than a minute. If the amp feels hot and the fan
is not running, it needs to be serviced.
Check the position of the CROSSOVER switch on the rear
panel. Set on FULL RANGE for normal, independent use of
each channel.
CHANNEL 2 INPUT SEEMS DEAD.
Check the position of the CROSSOVER switch on the rear
panel. Set on FULL RANGE for normal, independent use of
each channel.
AMPLIFIER SOUNDS DISTORTED.
If the red CLIP LED is flashing, the amplifier is being played
beyond its normal rated power. GuardRail™ circuitry will reduce
volume somewhat to prevent severe overdrive, but if the input
signal is further increased, the limiter can be overridden, with
increased distortion.
If the speakers or speaker cables are shorted or defective,
the amplifier may distort at lower-than-normal levels, with
increased flashing of the red CLIP LED. This should be
checked by trying an alternate speaker and cable.
If too many speakers are connected to each channel
(impedance below 4 ohms), the amp will overload more
easily and will probably run hot.
If the sound is distorted or garbled without flashing the red
CLIP LED, the distortion is not occurring inside the amplifier.
Either the speaker is bad or the input signal is distorted.
• Confirm that the speaker is OK by trying a different unit.
• Input overload can occur if the amplifier Gain controls are set
too low, and the input source is overdriven to compensate
Reduce the source volume until the distortion clears up, and
increase amp Gain to reach the desired level. It is generally
desireable to keep the amp gains at or near their full,
clockwise, position.
• Check all input connections. Do not plug two different sources
into the same channel. Use a mixer to blend sources.
The green LED indicates the amp is producing a signal, so
sound should be heard if the speaker is connected. Check
the speaker connections at both ends, and try a different
speaker.
NO SOUND, RED LED ON
BACKGROUND HUM
Balanced XLR or TRS cables are better for long runs. Hum can
be a problem when connecting to TV-cable rigs, since the TV
cable often creates a ground conflict. Request or install a TVcable isolator to reduce this problem.
Hum can also occur earlier in the signal chain, depending on the
types of connections. It often helps to plug everything into the
same AC strip, if the total power consumption is not excessive.
As a last resort, mild hum can sometimes be reduced by
lowering the amp gain, and increasing the source gain to
compensate, but you must ensure that the source can deliver
the extra volume without overload distortion. If this does not
reduce hum, it is coming from the source.
AMPLIFIER NEEDS SERVICING
The following conditions indicate possible unsafe conditions
that require service before using. If observed, unplug the AC
cord from the wall and when safe, remove the amp for
servicing.
• If the amplifier emits smoke or burning smells
• If the case is severely dented or deformed
• If the amplifier is soaked with any fluid
• If internal parts sound loose
• If the AC breaker trips when power is applied
• If the amplifier is dropped, carefully inspect for damage or
loose parts before attempting to use.
11
SPECIFICATIONS
GX3
GX5
GX7
8Ω, both channels driven
300 W
500 W
725W
8Ω, single channel driven
350 W
600 W
800W
4Ω, both channels driven
425 W
700 W
1000W
4Ω, single channel driven
500 W
850 W
1200W
2Ω, both channels driven, 1% clipping
200 W
350 W
600W
SIGNAL TO NOISE (20 Hz – 20 kHz)
100 dB
INPUT SENSITIVITY
VOLTAGE GAIN AT 8Ω
1.2 Vrms
32.2 dB
34.4 dB
36.1 dB
OUTPUT CIRCUITRY
Class B
2-tier Class H
2-tier Class H
POWER REQUIREMENTS (1/8 power, pink noise
at 4Ω 120 V AC)
6.3 A
6 A
11.5 A
DISTORTION (1 dB below rated power, 1 kHz)
8Ω, less than 0.02%
4Ω, less than 0.05%
FREQUENCY RESPONSE
20 – 20kHz, +0, -1dB
DYNAMIC HEADROOM, 4Ω
2dB
INPUT IMPEDANCE
Greater than 20K ohms (balanced or unbalanced)
MAXIMUM INPUT LEVEL
+24 dB (16 Vrms)
INPUT CONNECTORS, each channel
3-pin XLR and 1/4” TRS, balanced, parallel
Phono, unbalanced
OUTPUT CONNECTORS, each channel
Speakon®, 1/4”, Binding Posts
AMPLIFIER AND LOAD PROTECTION
Short circuit, open circuit, thermal, RF protection
Load protected against DC faults
CONTROLS AND INDICATORS, FRONT PANEL
Gain controls, 21 detents
Red Clip LEDs, proportional, 0.1% THD threshold.
Green Signal LEDs, threshold -35 dB
Blue Power LED, AC-on.
CONTROLS, REAR PANEL
Full Range / Crossover switch
100 Hz, 3rd order LP (sub), 2nd order HP (top).
DIMENSIONS (HWD)
3.5” (2RU) x 19” x 10.1” (89 mm x 483 mm x 257 mm)
WEIGHT – Shipping / Net
31 / 27 lbs (14.1 / 12.1 kg)
AGENCY APPROVALS
UL, CE, RoHS / WEEE compliant. Meets FCC Class B EMI limits.
SPECIFICATION SUBJECT TO CHANGE WITHOUT NOTICE.
OUTPUT POWER, 1 kHz, 0.1 % clipping
32 / 28 lbs (14.6 / 12.6 kg)
EN
22 / 17 lbs (10 / 7.7 kg)
AC POWER CONSUMPTION 1/8 power, ohms (AC Current and Heating, 120Vac)
GX3
Operating Condition
AC amps
GX5
BTU / hr
AC amps
GX7
BTU / hr
AC amps
BTU / hr
Idle
0.2
44
0.3
60
0.6
82
8 + 8 ohms, 1/8 power (1)
4.1
904
3.3
734
7.6
1183
8 + 8 ohms, 1/3 power (2)
6.1
1160
8.5
1456
13.4
1807
8 + 8 ohms, full power (3)
9.75
1109
16.2
1891
26.5
2167
4 + 4 ohms, 1/8 power (1)
6.3
1515
5.8
1160
11.5
1908
4 + 4 ohms, 1/3 power (2)
9.4
2105
11.2
2162
18.5
2612
4 + 4 ohms, full power (3)
15.0
2297
24.5
3754
39.4
4478
(1) 1/8 power represents typical operating conditions.
(3) Full power is breaker limited to short periods.
(2) 1/3 power represents peak program levels.
(4) For 230V, multiply AC current by 0.5. For 100V, multiply AC current by 1.25.
WARRANTY
(USA only; other countries, see your dealer or distributor)
Disclaimer
QSC Audio Products, LLC is not liable for any damage to amplifiers or any other equipment that is caused by negligence
or improper installation and/or use of this loudspeaker product.
EN
QSC Audio Products 3 Year Limited Warranty
QSC Audio Products, LLC ( QSC ) guarantees its products to be free from defective material and / or workmanship for a
period of three (3) years from date of sale, and will replace defective parts and repair malfunctioning products under this
warranty when the defect occurs under normal installation and use - provided the unit is returned to our factory or one
of our authorized service stations via prepaid transportation with a copy of proof of purchase (i.e., sales receipt). This
warranty provides that the examination of the return product must indicate, in our judgment, a manufacturing defect. This
warranty does not extend to any product which has been subjected to misuse, neglect, accident, improper installation, or
where the date code has been removed or defaced. QSC shall not be liable for incidental and/or consequential damages.
This warranty gives you specific legal rights. This limited warranty is freely transferable during the term of the warranty
period. Customer may have additional rights, which vary from state to state.
In the event that this product was manufactured for export and sale outside of the United States or its territories, then
this limited warranty shall not apply. Removal of the serial number on this product, or purchase of this product from
an unauthorized dealer, will void this limited warranty. Periodically, this warranty is updated. To obtain the most recent
version of QSC’s warranty statement, please visit www.qscaudio.com. Contact us at 800-854-4079 or visit our website at
www.qscaudio.com.
How to Contact QSC Audio Products
Mailing address:
QSC Audio Products, LLC
1675 MacArthur Boulevard
Costa Mesa, CA 92626-1468 USA
Telephone Numbers:
Main Number (714) 754-6175
Sales & Marketing (714) 957-7100 or toll free (USA only) (800) 854-4079
Customer Service (714) 957-7150 or toll free (USA only) (800) 772-2834
Facsimile Numbers:
Sales & Marketing FAX (714) 754-6174
Customer Service FAX (714) 754-6173
World Wide Web:
www.qscaudio.com
E-mail: info@qscaudio.com
service@qscaudio.com
TM
QSC Audio Products, LLC 1675 MacArthur Boulevard Costa Mesa, California 92626 USA
©2007 “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising