Electro-Voice Q44 EDS User Manual

Q44

Stereo Power Amplifier

• 280 watts per channel at 8 ohms;
450 watts per channel at 4 ohms;
650 watts per channel at 4 ohms
at 1 kHz

• 900 watts per channel bridged at
8 ohms;1,300 watts bridged at
4 ohms at 1 kHz

• State-of-the-art limiters driven by a
sophisticated input/output compara­tor ensure freedom from amplifier
clipping

• High-current Neutrik Speakon
connectors for channels A, B and
bridged operation for loss-free
connections

• Active-balanced XLR-type input and
paralleled XLR-type output connec­tors provide easy signal routing

• Rear-mounted dB-scaled detented
level controls for easy control of gain

®

output

Description

The Electro-Voice Q44 amplifier is a very
high-quality power amplifier designed to
elicit excellent performance from any
speaker system. Its low distortion and sub­stantial headroom ensure that program ma­terial will be accurately amplified.

Each channel of the Q44 delivers more
than 230-watts continuous average power
into 8 ohms, 350 watts into 4 ohms and
450 watts into 2 ohms over the full audio
frequency range. In the bridged mode, the
amplifier can deliver more than 900 watts into
8 ohms and 1,300 watts into 4 ohms at less
than 1% THD. The power supply with its
large torodial transformer gives the ampli­fier impressive headroom and current output
capability.

The Q44 contains 16 high-power output de­vices with 4,000 watts of dissipation capa­bility. These devices are protected from over­heating by two, three-speed temperature-sen­sitive fans. The fans are quiet enough to per­mit use of the Q44 in noise-sensitive appli­cations such as recording studios and houses
of worship.

The output devices are mounted to two large,
extruded aluminum heat sinks that are engi-

neered to minimize thermal gradients and
allow the amplifier to operate safely into low­impedance loads. The output devices have a
maximum junction temperature of 200

o

(392

F), so high operational temperatures
present no problems. The output devices are
mounted directly to the heat sinks without
mica insulators to ensure better dissipation
of heat.

The Q44 has sophisticated protection circuits
that guard it and the load from problems.
Protection circuits guard against overload,
over-temperature, shorted outputs, radio-fre­quency interference and dc faults. The out­put devices are protected against damage
from the reverse feeding of electrical energy
(back EMF) from the load and are switched
on via relays to avoid transients which could
damage speakers.

The Q44 has built-in limiters to protect
speakers from the deleterious effects of am­plifier clipping. The limiter’s action is con­trolled by very sophisticated input/output
comparators which are designed to preserve
the sonic integrity of the source.

The Q44 has electronically-balanced XLR­type input and signal output connectors that
allow easy, problem-free connections and
signal routing. The amplifier has an input

o

C

routing switch that allows selection of either
normal dual-channel operation or parallel
mono operation, which routes an input to
both channels but still allows independent
level control.

The Q44’s professional Neutrik Speakon
output connectors provide sturdy, reliable
connections and allow use of heavy wire for
loss-free signal transmission. There are sepa­rate output connectors for channels, A and
B, and for the bridge mode. The bridge mode
connector is sealed with a plastic cover to
prevent connection errors.

To prevent ground loops from occurring, the
Q44 is equipped with a ground-lift switch.
When the amplifier is operated in a rack with
units of different ground potential, the switch
may be adjusted to eliminate hum.

Separate potentiometers on the rear panel of
the Q44 allow easy regulation of gain. There
is easily readable nomenclature to ensure
easily repeatable control settings.

The Electro-V oice Q44 is an excellent choice
for high-quality professional sound system
applications which require excellent sound
quality, speaker protection and the highest
level of construction quality and long-term
reliability.

®

Q44 Stereo Power Amplifier

Architects’ and Engineers’
Specifications

The power amplifier shall be a dual-channel
model of solid-state design employing high­power output devices in a true-complemen­tary-symmetry output circuit. It shall be ca­pable of operating from a 120/230/240-V, 50/
60 Hz ac line. The power amplifier shall con­tain a limiter circuit driven by a high-qual­ity input/output comparator to protect the
load from damage by amplifier clipping. The
amplifier shall meet various worldwide
safety requirements including Underwriters's
Laboratories UL-813 Standard, Canadian

Q44 Stereo Power Amplifier

Standard, and CE-Standard
The amplifier shall contain sensing circuitry

to provide protection for the output transis­tors against over temperature, excessive out­put voltage, shorted loads, excessive phase
shift and back-EMF current. The load shall
be similarly protected against start-up/shut­down transients, low ac line voltage and dc.

Rear-mounted controls shall include detented
level potentiometers for each channel, an
input routing switch for selecting dual/ste­reo or parallel mono operation, a switch for
selecting dual/stereo or bridged operation
and a chassis groundlift switch. Rear­mounted input connectors shall include a 3­pin female XLR-type connector wired in
parallel with a male 3-pin XLR-type output
connector for signal routing. Output connec­tors shall be Neutrik Speakon NL4MP’s for
channels A and B, and another for bridged
operation.

Front-panel indicators shall include power
on, a protection indicator and separate sig­nal present and limiter indicators for each
channel. Front-panel controls shall include
a power on switch.

The power amplifier shall meet the follow­ing performance specifications: rated output

power from 20-20,000 Hz at less than 0.2%
THD, each channel 230 watts into 8 ohms,
350 watts into 4 ohms and 450 watts into
2 ohms. In bridged mode at 1 kHz, the am­plifier shall deliver 900 watts into 8 ohms
and 1,300 watts into 4 ohms. Hum and noise
shall be at least 103 dB (A weighted) below
rated output power; damping factor shall be
greater than 300 at any frequency up to 1 kHz
in any mode with an 8-ohm load; THD (total
harmonic distortion) shall be less than 0.05%
at 1 kHz at rated output power; crosstalk shall
be greater than -80 dB at 1 kHz at rated out­put power; transient intermodulation distor­tion (DIM 30), shall be less than 0.03%.
Dimensions shall be 132.5 mm (5.25 in)
high x 483 mm (19.0 in) width x 385.5 mm
(15.7 in) deep. Net weight shall be 16 kg
(35.2 lb). Color shall be light gray.

The power amplifier shall be the Electro­Voice Q44.

Limited Warranty

Electro-Voice products are guaranteed
against malfunction due to defects in mate­rials or workmanship for a specified period,
as noted in the individual product-line
statement(s) below, or in the individual prod­uct data sheet or owner’s manual, beginning
with the date of original purchase. If such
malfunction occurs during the specified pe­riod, the product will be repaired or replaced
(at our option) without charge. The product
will be returned to the customer prepaid. Ex-
clusions and Limitations: The Limited
W arranty does not apply to: (a) exterior fin­ish or appearance; (b) certain specific items
described in the individual product-line
statement(s) below, or in the individual prod­uct data sheet or owner’s manual; (c) mal­function resulting from use or operation of
the product other than as specified in the
product data sheet or owner’s manual; (d)

malfunction resulting from misuse or abuse
of the product; or (e) malfunction occurring
at any time after repairs have been made to
the product by anyone other than Electro­Voice Service or any of its authorized service
representatives. Obtaining Warranty Ser-
vice: To obtain warranty service, a customer
must deliver the product, prepaid, to Elec­tro-Voice Service or any of its authorized
service representatives together with proof
of purchase of the product in the form of a
bill of sale or receipted invoice. A list of
authorized service representatives is avail­able from Electro-V oice Service at 600 Cecil
Street, Buchanan, MI 49107 (800/234-6831
or FAX [phone]). Incidental and
Consequential Damages Excluded: Prod­uct repair or replacement and return to the
customer are the only remedies provided to
the customer. Electro-Voice shall not be li­able for any incidental or consequential dam­ages including, without limitation, injury to
persons or property or loss of use. Some
states do not allow the exclusion or limita­tion of incidental or consequential damages
so the above limitation or exclusion may not
apply to you. Other Rights: This warranty
gives you specific legal rights, and you may
also have other rights which vary from state
to state.

Electro-Voice Electronics are guaranteed
against malfunction due to defects in mate­rials or workmanship for a period of three
(3) years from the date of original purchase.
Additional details are included in the Uni­form Limited Warranty statement.

For warranty repair or service informa­tion, contact the service repair department
at: 616/695-6831 or 800/685-2606.

For technical assistance, contact Technical
Support at 800/234-6831 or 616/695-6831,
M-F, 8:00 a.m. to 5:00 p.m. Eastern Stan­dard Time.

Specifications subject to change without
notice.

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