Crest Audio MULTIPLEX 900 User manual

description features
TourClass
®
protection circuits
acl active clip limiting prevents speaker damage by
providing gentle gain reduction at the clipping threshold.
igm instantaneous gain modulation monitors speaker loads to
detect conditions that may overstress output devices, allowing safe
operation into difficult impedances.
autoramp gradually increases gain to the attenuator level-
settings when the amplifier is turned on.
Protection features include: thermal runaway,input overload, dc,
short circuit, in-rush current, and turn-on/turn-off transients.
The Crest Audio Multiplex 900 integrates cost-effective design
with exceptional sonic accuracy, long-term reliability, and the
basic features required for cinema sound applications. The
Multiplex 900’s remarkable price/performance ratio is the
result of innovative engineering and highly efficient manufac-
turing in Crest's modern USA facility along with nearly two
decades of leadership in professional amplifier design. The
Multiplex 900 offers a welcome balance of exceptional audio
performance and overall value. However, no compromises in
component selection or quality control were permitted as a
shortcut to cost reductions.
In every respect, the Multiplex 900 embodies the Crest Audio
tradition of roadworthy ruggedness and reliability. For exam-
ple, the Multiplex 900 includes the same TourClass protection
features as found in Crest’s CA and CK Family amplifiers.
The Multiplex 900 will endure virtually any type of mishap or
system stress – whether from uncontrolled upstream oscilla-
tion, extreme ambient heat, or accidental shorting – without
damage to internal circuitry or connected speakers.
.robust “over-built” power supply – massive filter capacitors and
a high-output custom transformer provide ample current for solid
bass performance, even when driving low impedance loads.
.more output transistors – by using more output devices than
comparable models, the Multiplex 900 puts less stress on each device
yielding a wider safe operating area (SOA) and long-term reliability.
.wide-band design – frequency response extends from 10Hz to
20kHz (-3dB @ 165kHz), ensuring powerful sub-bass performance as
well as detailed, transparent high-frequency response.
.more effective cooling – large, extruded aluminum heatsink and
front-mounted, two-speed 4-inch fan prolonging amplifier life by
minimizing internal temperatures.
.front panel magnetic circuit-breaker/power switch
.rear panel knobs attenuators (with cover)
.differentially-balanced ¼-inch TRS and Barrier Strip Input Connectors
.five-way binding post or Speakon output connectors
(market dependent)
.LED indicators –
SIGNAL PRESENT, CLIP, ACTIVE, and PROTECT
.stereo/bridged-mono mode select switch
.five-year warranty*
power specifications 8Ωstereo 4Ωstereo 8Ωbridged
1kHz, 0.01% THD+N 230w 400w 800w
Power figures are watts per channel, both channels driven.
900
Multiplex 900 power amplifier
4Ωstereo Multiplex 1100 Multiplex 1500
1kHz, 0.01% THD+N 550w 750w
power specifications:
other Multiplex Series power amplifiers

1kHz, 0.1% THD+N 20Hz–20kHz, 0.1% THD+N
230W225 W
400W400 W
800W800 W
52.3V rms, 74V peak each channel
10Hz–20kHz, +0 / -0.3dB,-3dB@165kHz
20Hz–20kHz, +0 / -0.23dB
<1.0% rated power @4Ω, 1kHz
<0.1% rated power @ 8Ω, 60Hz and 7kHz
1000:1 10–400Hz @8Ω
>-64dB @1kHz
1.0V
>20kΩ balanced, >10kΩ unbalanced
-105dB, A-weighted below rated power
> -60dB @1kHz below rated power
AB
100–240 vac @50–60Hz factory configured
15A @120V
<7.2A @120V
<10.4A @120V
<15A @120V
<2.0A @120V
2000 BTU/Hr
2900 BTU/Hr
front-to-side, one 110 CFM, two-speed fan
trs (tip +) and Barrier Strip
speakon connectors or five-way output binding posts
front panel: magnetic circuit breaker power switch
rear panel: two attenuators, mode select
acl, signal, protect
acl, igm, autoramp, short circuit, dc voltage, turn-on/-off transient,
current in-rush, sub/ultrasonic input
steel chassis 14 gauge
5.25” x 19” x 12” 133 x 483 x 305mm height x width x depth
gross: 46lbs 20.9kg
net: 44lbs 20.0kg
five years* USA, Canada, United Kingdom, and many other countries
specifications
Crest Audio Inc.
100 Eisenhower Dr., Paramus NJ 07652 USA
TEL: [phone] FAX: [phone]
http://www.crestaudio.com
Crest Audio specification literature is available
in downloadable PDF format at our website
http://www.crestaudio.com
Power figures are watts per channel,
both channels driven.
©¹⁹⁹⁸ crest audio inc.
Crest Audio reserves the right to make
improvements in manufacturing or design
which may affect specification.
*A4500006*
Multiplex 900 power amplifier
The power amplifier shall have two channels.
Each channel shall deliver a minimum of
230Wat 8Ωand400Wat 4Ω, both channels
driven, 20Hz–20kHz, <0.1% THD+N. In
bridged-mono mode, it shall deliver 800Wat
8Ω, <0.1% THD+N.
The amplifier shall have circuitry to protect itself
and the speaker load from output short circuits,
DC voltage on outputs, and thermal overload.
The amplifier shall include circuitry to gradually
increase gain to attenuator setting levels when
the amplifier is turned on, and circuitry for
impedance sensing and clip limiting.
The amplifier shall have a voltage gain of
X40 with an input sensitivity of 1.0V, for rated
power at 8Ω. The hum and noise level shall
be greater than 105dB below rated output,
A-weighted. SMPTE IMD shall be less than
0.1%, rated power at 8Ω. The amplifier shall
have a class AB output. The frequency
response shall be greater than 20Hz–20kHz,
+0/-0.3dB (1W/8Ω).
The amplifier shall operate at 100–240VAC,
50–60Hz (configured at factory). Maximum
current draw shall not exceed 15Aat 120VAC,
(circuit breaker limited), with both channels dri-
ving continuously into a 4Ωresistor.
The amplifier front-panel shall include ACL,
SIGNAL, PROTECT LED indicators for each chan-
nel and a combination power switch/magnet-
ic circuit breaker.
Rear panel input connectors shall be TRS output.
A rear-panel AC mains cord having an appro-
priate AC plug for the intended operating volt-
age shall be provided (market dependent).
The packaging of the amplifier shall allow for
standard rack mounting without requiring
space between similar units. Dimensions shall
be 19" (483mm) wide, 5.25" (133mm) high
and 12" (483mm) deep. It shall weigh 44lbs.
(20kg) net. The amplifier shall be designated
the Crest Audio Model Multiplex 900.
v. 1.0 7/28/98
stereo power 8Ω
4Ω
bridged mono power 8Ω
maximum output voltage
frequency response 1W@ 8Ω
power bandwidth rated power @ 4Ω, 1% THD+N
THD+N
SMPTE IMD
damping factor
input CMRR
input sensitivity
input impedance
hum and noise
crosstalk
gain
class
power supply
circuit breaker rating 4Ω
current draw 1/8 power, 4Ω
1/3 power, 4Ω
at power-up
at idle
thermal emissions 1/8 Power, 4Ω
1/3 Power,4Ω
cooling
input connectors
output connectors
controls
LED indicators
TourClass®protection
construction
dimensions
weight
warranty
architect’s specifications
rear view 900
Power figures are
watts per channel,
both channels driven.
*Three-year Warranty
with two additional years,
if Registration Card is
sent to Crest Audio.