Crest Audio PRO SERIES 7301 User manual

Power Specifications Both ch. @ 4ΩLows @ 2Ω/ Highs @4ΩLows @ 4Ω/ Highs @8ΩLows @ 8Ω/ Highs @16Ω
High Frequency Power @ 1kHz, <0.05% THD 940 Watts 990 Watts 940 Watts 670 Watts
Low Frequency Power @ 100Hz, <0.1% THD 240 Watts 220 Watts 125 Watts 95 Watts
Figures are Watts per channel, both channels driven.
Product Description
The Crest Audio 7301 is a two rack space, compact power ampli-
fier specifically designed for use in bi-amplified systems, includ-
ing stage monitor, studio monitor and front-of-house applica-
tions. The low frequency channel (Ch. A) utilizes class H opera-
tion, which increases efficiency and yields higher output power
on the low end. The high frequency channel (Ch. B) utilizes class
AB operation which is optimized for precise reproduction of mid
and high-frequency signals.
For bi-amped systems, the Crest Audio 7301 is unmatched in
quality, efficiency and sonic accuracy. When used in combina-
tion with a crossover (including those available in the Crest
Audio Octal Socket Accessory line), the 7301 becomes a com-
plete bi-amplification system, in a space-efficient package.
The 7301 is fully compatible in design with the other Crest
Audio Professional Series amplifiers, Octal Socket Accessories,
and the NexSys®computer controlled audio system.
Design and Construction
The no-compromise approach in the 7301’s electrical design and
mechanical construction provides the ultimate in reliability and
performance. Only high-grade components are used for the mod-
ular sub-assemblies in this ultra-strong, steel single piece chassis.
7301 Features
• Crest Audio’s legendary “overbuilt” power supply
• Toroidal power transformer
• Latest generation of high-speed, wide-bandwidth output
devices
• Tunnel cooling with back-to-front air flow
• Dual, variable speed DC fans
• High thermal mass heat sinks
• Balanced XLR inputs
• 5-way output binding post connectors
• Rear panel ground lift jumper
• 7301 protection circuitry:
- Clip Limiting prevents speaker damage with gentle gain
reduction at clip threshold.
- IGM (Instantaneous Gain Modulation) monitors connected
loads to detect conditions that may overstress output
devices, allowing safe operation into nominal 2Ωimped-
ances.
- AutoRamp gradually increases gain to attenuator setting
level when amplifier is turned on.
- Other protection circuitry: comprehensive thermal manage-
ment, and short circuit, DC voltage, turn-on/off transient,
current inrush and sub/ultrasonic input protection.
• Recessed, stepped attenuators
• Front panel circuit breaker/power switch
• Modular construction
• Full five-year warranty
(USA, Canada, U.K. & many other countries).
®Crest Professional Series Amplifiers
are fully compatible with the NexSys
Computer-Controlled Audio system.
7301
POWER AMPLIFIER

Lows @ 100Hz, <0.1% THD+N Highs @ 1kHz, <0.05% THD+N
940W 240W
990W 220W
940W 125W
670W 95W
83V(Low Ch.) 49V(High Ch.)
117V(Low Ch.) 69V(High Ch.)
20 Hz-20 kHz, -3dB @ 53kHz
20 Hz-20 kHz, +0/-0.2dB
Clip Limit, IGM, AutoRamp, High Temp, short-circuit,
DC voltage, turn-on/off transient, sub/ultrasonic input.
<0.02% @ 800W (Low Ch.); 200W ( High Ch.)
400:1
>60 dB
1.53V RMS (Low ) .79V RMS (High )
X40
>20kΩ
> -100 dB
> -60dB
H (Low Channel); AB (High Channel)
Female XLR (pin 3+), Octal Socket
5-way output binding posts
80,000 µF
100V-240V, 50-60Hz
1.2A
7.0A
12.25A
21.0A
2300 BTU/hr
3700 BTU/hr
Rear to front tunnel heatsink, 2 variable speed DC fans
Front panel: 2 attenuators, circuit breaker/power switch;
Rear panel: signal ground lift jumper.
Clip/Limit, Signal, Temp/DC, Active
16 ga. steel chassis, 0.187" (5mm) aluminum front panel
3.5"x19"x15" (16" to rear ears)
89mm x 483mm x 381mm (406mm to rear ears)
57 lbs. (25.88 kg.), 52 lbs. (23.60 kg.)
5 years, parts and labor†
Both Channels @ 4Ω
Lows @ 2Ω, Highs @ 4Ω
Lows @ 4Ω, Highs @ 8Ω
Lows @ 8Ω, Highs @ 16Ω
Max RMS Output Voltage (each channel)
Peak Output Voltage (each channel)
Frequency Response (+0 / -0.3dB, 1W/8Ω)
Power Bandwidth (rated power at 4Ω, 1% THD+N)
Protection Circuitry
THD+N (rated power at 4Ω, 1kHz)
Damping Factor (10-400Hz at 8Ω)
Input CMRR (1kHz)
Input Sensitivity (8Ω)
Voltage Gain
Input Impedance (balanced)
Hum and Noise (“A” weighted, full power, 4Ω)
Crosstalk (“A” weighted, full power, 4Ω)
Class
Input Connectors (per channel)
Output Connectors (per channel)
Filter Storage
Power Supply (factory configured)
Idle Current Draw (120V)
1/8 Power Curr. Draw (typical music, 120V/4Ω)
1/3 Power Curr. Draw (continuous music, 120V/4Ω)
Max Curr. Draw (circuit breaker rating, 120V/4Ω)
Thermal Emissions (1/8 Power, 4Ω)
Thermal Emissions (1/3 Power, 4Ω)
Cooling
Controls
LED Indicators (per channel)
Construction
Dimensions (Height x Width x Depth)
Gross Weight, Net Weight
Warranty
† USA, Canada, U.K., and many other countries. Power figures are watts per channel, both channels driven. Crest Audio reserves the
right to make improvements in manufacturing or design which may affect specifications. Crest Audio specification literature is available
in downloadable PDF file format; visit our website at http://www.crestaudio.com. ©1997 Crest Audio Inc. 5/21/97
v. 2.4 4/9/97 B5000008
Crest Audio Inc.
100 Eisenhower Dr., Paramus NJ 07652 USA
TEL: [phone] FAX: [phone]
http://www.crestaudio.com
Printed in USA
7301 POWER AMPLIFIER
SPECIFICATIONS Architect’s & Engineer’s Specifications
The monitor amplifier shall consist of two dissimilar chan-
nels; one of class H operation and modulated power supply
(ch. A). and one of class AB operation (ch. B). The class H
channel shall deliver a minimum of 940 watts at 4 ohms
with both channels driven (@ 100Hz, <0.1% THD+N).
The class AB channel shall deliver a minimum of 240 watts
at 4 ohms with both channels driven (@ 1kHz, <0.05%
THD+N).
The amplifier shall be rear-to-front tunnel-cooled, with two
variable-speed DC fans.
The amplifier shall have circuitry to protect itself and the
speaker load from output short circuits, DC voltage on out-
puts, and thermal overload. The amplifier shall include cir-
cuitry to gradually increase gain to attenuator setting lev-
els 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 1.53V (low channel) and .79V (high
channel) for rated power at 4 ohms. The hum and noise
level shall be greater than 100 dB below rated output, “A”
weighted. The frequency response shall be greater than
20Hz-20kHz, +0, -.3dB (1W/8Ω).
The amplifier shall operate at 100-240V, 50-60 Hz AC
(configured at factory). Maximum current draw at 120V
shall be no greater than 21A, both channels driven contin-
uously into a 4 ohm resistive load.
The amplifier front panel shall include Active, Temp/DC,
Signal Present and Clip/Limit LED indicators for each
channel, a combination power switch/magnetic circuit
breaker and recessed and detented gain pots.
Rear panel input connectors shall be XLR type, one female
per channel. Output connectors shall be 5-way binding
posts, two pair per channel. A signal/ground lift jumper
shall be provided.
A rear-panel AC mains cord having an appropriate AC
plug for the intended operating voltage 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 3.5" (89mm) high x 19"
(483mm) wide x 15" (381mm) deep. It shall weigh 52 lbs.
(23.60kg) net. The amplifier shall be designated the Crest
Audio Model 7301.
USA ONLY
MODEL # MAXIMUM
INPUT CURRENT
@ 120V, 60Hz
OUTPUT POWER
IN WATTS PER
CHANNEL, 2Ω
OUTPUT - CLASS 2 WIRING MAY BE USED
7301 21 AMPS CH. A 990W
CH. B 220W
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
AVIS : RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT
EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC
ÉLECTRIQUE, NE PLACEZ PAS CETAPPAREIL SOUS LA PLUIE OU Á
L'HUMIDITÉ
{
Designed & manufactured in the USA by:
Crest Audio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
OUT LOWS
OUT HIGHS
PUSH
PUSH
IN
LOWS
PIN 3+
HIGHS
SIGNAL
GROUND
LIFT
IN
HIGHS
LOWS
Rear View
*B5000008*