Crest Audio LT1000 User manual

SERIES
Features Description
• Dramatically reduced net weight
• Linear power supply / switching output stages
• Very low current draw
• Latest generation of high-speed, wide-bandwidth output devices
• Cooled by variable speed fan with back-to-front airflow
• Inputs - Balanced female XLR, 1/4” TRS and three pin phoenix
• Outputs - Speakon and five-way binding posts
• Mode selector switch for stereo, parallel and bridged-mono operation
• Ground-lift switch and rear panel circuit breaker
• Recessed, stepped attenuators with removable knobs
• 16-gauge steel chassis, 14-gauge steel front-panel
TourClass®protection circuits
ACL (Active Clip Limiting) prevents speaker damage by providing
gentle gain reduction when signal approaches the clipping threshold.
IGM (Instantaneous Gain Modulation) monitors speaker loads to
detect conditions that may overstress output devices. This allows
safe operation into nominal 2Ωspeaker loads.
AUTORAMP gradually increases gain to the attenuator level-settings
when the amplifier is turned on. This prevents abrupt turn-on level.
Other protection features include: short circuit, dc voltage, com-
prehensive thermal management, current in-rush turn-on/off tran-
sient, and sub/ultrasonic input.
The LT Series amplifier is the first in a family of elevated effi-
ciency amplification from Crest Audio. With sonic perform-
ance still the primary priority, the LT Series uses a combina-
tion of a linear power supply and a Class D output to deliver,
Crest Power in a compact and cost-effective package.
A full complement of features and power-points makes this
series very versatile, whether powering nightclub systems or
high school gymnasiums. The LT series amplifiers bring a new
generation of amplification to Crest Audio.
Linear-toroid power supply
A traditional linear power supply is used in the LT Series.
Because of the efficiency of the switching output stage
(approx 93%), the transformer does not need to be as big or
as heavy. This gives the LT Series an advantage in delivering
more power in a more compact package. The efficiency of the
output stage also gives the power supply the ability to handle
heavy-duty cycles without compromising sonic integrity
Switching output stage
To maintain sonic quality along with incorporating the advan-
tages of a switching output stage, Crest Audio’s engineering
has two years of development time in this new generation
Class D amplifier. The multiple rail technology is the key to its
efficiency and low operating temperature. An additional
advantage to this design is the amount of power needed over
time. This amplifier will dramatically reduce the number of kW
/ hr needed to operate.
power specifications 8Ωstereo 4Ωstereo 2Ωstereo 8Ωbridged 4Ωbridged
1kHz, 0.1% THD+N
LT2000 560w 1000w 1200w 2000w 2400w
LT1500 400w 750w 900w 1500w 1800w
LT1000 280w 500w 650w 1000w 1300w
LT1000 - LT2000
Power Amplifiers
(LT2000 model shown)

Specifications LT Series Power Amplifiers
stereo power 8Ω
4Ω
2Ω
bridged mono power 8Ω
4Ω
maximum output voltage
frequency response 1W @ 8Ω
power bw rated power @ 4Ω, 1% THD+N
THD + N
smpte imd
damping factor
input CMRR
input sensitivity @ 8Ω
input impedance
hum and noise
crosstalk
class
power supply
circuit breaker rating (120V/230V)
current draw (120VAC) 1/8 power4Ω
1/3 power, 4Ω
at idle
thermal emissions 1/3 Power, 4Ωbtu / hr
cooling
input connectors
output connectors
controls
LED indicators
construction
dimensions
weight
LT1000 LT1500 LT2000
280W 400W 560W
500W 750W 1000W
650W 900W 1200W
1000W 1500W 2000W
1300W 1800W 2400W
53V rms 64V rms 72V rms
1kHz, 0.1% THD+N Power figures are watts per channel, both channels driven.
20Hz–20kHz, +0 / -1dB
20Hz–20kHz, +0 / -1dB
<0.1% rated power @ 4Ω, 1kHz
<0.03% rated power @ 8Ω
400:1 @ 8Ω
>60dB @ 1kHz
.775 V for full rated output power
>20kΩbalanced, >10kΩunbalanced
-100dB, A-weighted
> -60dB below max rated power (1kHz)
D
Linear with toroid transformer
10A / 6A 15A / 10A 20A / 12A
1.8A 2.4A 3.0A
4.0A 5.5A 7.0A
0.6A 0.6A 0.6A
1220 1430 2100
Back to front via variable speed DC fan
balanced female XLR, 1/4"TRS, and three pin Phoenix™
Speakon™connectors and five-way binding posts
front panel: twin recessed stepped attenuators, power switch
rear panel: signal ground-lift, mode select, circuit breaker
signal level, protect, active, ACL / IGM
16-gauge steel chassis, 14-gauge steel front-panel (double thickness in rack ear areas)
3.5" x 19" (front panel) 17" (chassis) x 14”(15.25" to rack ears) hxwxd
30 lbs 32.5 lbs 35 lbs
Crest Audio Inc.
16-00 Pollitt Dr. Fair Lawn NJ 07410 USA
TEL: [phone] FAX: [phone]
www.crestaudio.com
*A4400078*
Crest Audio reserves the right to make improvements in manufacturing or design which may affect specifications.
3.21.02
v.1.6
Architects’ & Engineers’ Specifications:
The power amplifier shall consist of 2 chan-
nels. Each channel will deliver a minimum of
(280 / 400 / 560) watts at 8 ohms, (500 / 750 /
1000) watts at 4 ohms (650 / 900 / 1200) watts
at 2 ohms, 20Hz - 20kHz. In Bridged mono
mode, it will deliver a minimum of (1000 / 1500
/ 2000) watts at 8 ohms and (1300 / 1800 /
2400) watts at 4 ohms, 20 HZ - 20 kHz. It shall
weigh (30 / 32.5 / 35) lbs. The amplifier shall
incorporate protection circuitry against output
short circuits, DC voltage on outputs, thermal
overload and load protection due to any form
of amp failure. It will include impedance sens-
ing circuitry, and RMS clip limiter and Auto-
Ramp signal control. The amplifier shall have
a sensitivity of .775V at the input, which will
deliver full rated output power in any output
configuration. Sensitivity can be changed
internally to 1.2V for full rated output power.
The hum and noise level shall be greater then
100dB below rated output, "A" weighted. The
amplifier shall have a class D output stage with
a modulated power supply. The frequency
response shall be greater than 20 Hz - 20 kHz,
0 / -1 dB, at full rated output power @ 4 ohms,
.5%THD. The amplifier will operate at either
120 VAC, 60hz (safe operating range 100-
132VAC) or at 230 VAC, 50Hz (safe operating
range 200-264), voltage selection determined
at factory. Maximum current draw at 120V
shall be no greater then 15 A, both channels
driver continuously into 4 ohm load. Front
panel indicators shall include LED indicators
for Protect, ACL (automatic clip limit), Signal
level, and Active status. Front panel attenua-
tors will be recessed and detented. Input con-
nectors shall be XLR, 1/4" TRS and 3-pin
Phoenix, per channel. Output connectors shall
be 5-way binding posts and Speakon, per
channel. A switch shall enable the signal
ground to be lifted from the chassis. The pack-
aging of the amplifier shall allow for standard
rack mounting without requiring space
between similar units as long as rack is prop-
erly ventilated. Dimensions main chassis shall
be 17" wide (front panel is 19" wide), 14" deep
(15.25" including rear rack ears), 3.5" high.
The amplifier shall be designated the Crest
Audio Model (LT1000 / LT1500 / LT 2000).