Crest audio PRO 4801 SPECIFICATIONS

4801 POWER AMPLIFIER

Product Description

The Crest Audio Model 4801 is a compact, high-power amplifier designed to meet the most stringent demands of professional use in concert touring, studio monitoring, high-quality sound reinforcement, and professional installations.

A forced-air configuration is used to cool channel heat sinks mounted in a back-to-back tunnel arrangement. An actively balanced female XLR input connection, Octal Socket, and 5-way output binding posts are provided for each channel.

The 4801 is fully compatible in design with other Crest Audio Professional Series amplifiers, Octal Socket Accessories, and the NexSys® computer-controlled audio system.

Design and Construction

Crest Audio’s no-compromise approach in the 4801’s electrical design and mechanical construction adds up to the ultimate in reliability and performance. Only high-grade components are used for the modular sub-assemblies in their ultra-strong, single piece steel chassis

®Crest Professional Series Amplifiers

are fully compatible with the NexSys Computer-Controlled Audio system.

4801 Features

•NexSys-ready

•Toroidal power transformer

•Tunnel cooling

•Variable speed DC fan

•High thermal mass heat sinks

•Balanced XLR inputs

•5-way output binding post connectors

•Stereo/Parallel/Bridged Mono mode selector switch

•Rear panel ground lift jumper

•Extensive 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 2Ω imped-

ances.

-AutoRamp gradually increases gain to attenuator setting level when amplifier is turned on.

-Other protection circuitry: comprehensive thermal management, and short circuit, DC voltage, turn-on/off transient, current inrush and sub/ultrasonic input protection.

•Ultra-strong, single piece steel chassis

•Octal Accessory sockets

•Recessed, stepped attenuators

•Front panel circuit breaker/power switch

•Modular construction

•Five-year warranty

(USA, Canada, U.K. & many other countries).

P o w e r S p e c i f i c a t i o n s	8 Ω S t e r e o	4 Ω S t e r e o	2 Ω S t e r e o	8 Ω B r i d g e d	4 Ω B r i d g e d
1kHz, <0.025% THD+N	4 0 0 W	5 7 5 W	7 0 0 W	1 1 5 0 W	1 3 0 0 W
20Hz-20kHz, <0.05% THD+N†	3 0 0 W	4 8 0 W	6 0 0 W	9 6 0 W	1 2 0 0 W

Figures are Watts per channel, both channels driven. †Continuous sine wave power is limited by current rating of front panel circuit breaker and IGM circuit.

4 8 0 1 P O W E R A M P L I F I E R

S P E C I F I C AT I O N S

	1kHz, <0.025% THD+N	20Hz-20kHz, <0.05% THD+N
8Ω Stereo Power	400W	300W
4Ω Stereo Power	575W	480W
8Ω Bridged Mono Power	1150W	960W
2Ω Stereo Power	700W	600W
4Ω Bridged Mono Power	1300W	1200W
Max RMS Output Voltage (each channel)	60V
Peak Output Voltage (each channel)	85V
Frequency Response (+0 / -0.3dB, 1W/8Ω )	20 Hz-20 kHz, -3dB @ 53kHz
Power Bandwidth (rated power at 4Ω , 1% THD+N)	20 Hz-20 kHz, +0/-0.2dB
Protection Circuitry	Clip Limit, IGM, AutoRamp, High Temp, short-circuit,
	DC voltage, turn-on/off transient, sub/ultrasonic input.
THD+N (rated power at 4Ω , 1kHz)	<0.025%
SMPTE IMD (rated power at 8Ω , 60Hz & 7kHz)	<0.1%
Damping Factor (10-400Hz at 8Ω )	400:1
Input CMRR (1kHz)	>60 dB
Input Sensitivity (rated power at 4Ω )	1.1V RMS
Voltage Gain	X40
Input Impedance (balanced)	>20kΩ
Hum and Noise (“A” weighted, full power, 4Ω )	> -100 dB
Crosstalk (“A” weighted, full power, 4Ω )	> -60dB
Class	H
Input Connectors (per channel)	Female XLR (pin 3+), Octal Socket
Output Connectors (per channel)	5-way output binding posts
Filter Storage	80,000 µF
Power Supply (factory configured)	100V-240V, 50-60Hz
Idle Current Draw (120V)	1.1A
1/8 Power Curr. Draw (typical music, 120V/4Ω )	5.6A
1/3 Power Curr. Draw (continuous music, 120V/4Ω )	11.46
Max Curr. Draw (circuit breaker rating, 120V/4Ω )	18.0A
Thermal Emissions (1/8 Power, 4Ω )	1803 BTU/hr
Thermal Emissions (1/3 Power, 4Ω )	3385 BTU/hr
Cooling	Rear to front tunnel heatsink, variable speed DC fan
Controls	Front panel: 2 attenuators, circuit breaker/power switch;
	Rear panel: mode switch, signal ground lift jumper.
LED Indicators (per channel)	Clip/Limit, Signal, Temp/DC, Active
Construction	16 ga. single piece steel chassis, .187" (5mm) alum. front panel
Dimensions (Height x Width x Depth)	3.5"x19"x15" (16" to rear ears)
	89mm x 483mm x 381mm (406mm to rear ears)
Gross Weight, Net Weight	54.0 lbs (24.52 kg.), 49.0 lbs (22.25 kg.)
Warranty	5 years, parts and labor†

† 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

Rear View

Architect’s & Engineer’s Specifications

The power amplifier shall have two channels. Each channel shall deliver a minimum of 300 watts at 8 ohms, 480 watts at 4 ohms and 600 watts at 2 ohms, 20Hz-20kHz, <0.05% THD+N. In bridged mono mode, it shall deliver 960 watts at 8 ohms and 1200 watts into 4 ohms, 20Hz20kHz, <0.05% THD+N.

The amplifier shall be rear-to-front tunnel-cooled, with a variable-speed DC fan.

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 1.1V for rated power at 4 ohms. The hum and noise level shall be greater than 100 dB below rated output, “A” weighted. SMPTE IMD shall be less than 0.1 % at rated power, 60Hz and 7kHz. The amplifier shall have a class H output stage with a modulated power supply. The frequency response shall be greater than 20Hz-20kHz, +0/-0.3dB (1W/8Ω ).

The amplifier shall operate at 100-240V, 50-60 Hz AC (configured at factory). Maximum current draw shall not exceed 18 amperes at 120VAC, (circuit breaker limited), with both channels driving continuously into a 4 ohm resistor.

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.

Input connectors shall be actively balanced and have female XLR-type, 3-pin connectors (pin 3+). Output connectors shall be 5-way output binding posts. Octal sockets for optional accessory modules and 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. The amplifier shall have a net weight of 49 lbs. (22.25kg) net. The amplifier shall be designated the Crest Audio Model 4801.

STEREO PARALLEL

BRIDGE

IN A

PUSH

IN B

PUSH

PIN 3+

v. 2.2 3/25/97 B5000004

*B5000004*

		CAUTION	OUT A
	A
		RISK OF ELECTRIC SHOCK
		DO NOT OPEN	+
		AVIS : RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR	BRIDGE
		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 CET APPAREIL SOUS LA PLUIE OU Á	OUT B
		L'HUMIDITÉ
			SIGNAL
			GROUND
	B		LIFT
		USA ONLY	Designed & manufactured in the USA by:

	MAXIMUM	OUTPUT POWER
MODEL #	INPUT CURRENT	IN WATTS PER
	@ 120V, 60Hz	CHANNEL, 2Ω
4801	18 AMPS	600W	Crest Audio Inc.
6001	21 AMPS	720W

	OUTPUT - CLASS 2 WIRING MAY BE USED	100 Eisenhower Dr.
		Paramus, New Jersey 07652 USA

Crest Audio Inc.

100 Eisenhower Dr., Paramus NJ 07652 USA

TEL: [phone] FAX: [phone]

http://www.crestaudio.com

Printed in USA