Crest Audio HD2 - User Manual

Product Description
The Crest Audio HD2 professional power amplifier is designed
to achieve unsurpassed sonic performance and long-term reliabil-
ity–even when operating under extreme stress–in touring or fixed
installation applications.
Absolute sonic accuracy is the hallmark of every Crest amplifier.
Bass is solid and defined to the limits of audibility, with ample
current reserves delivered by an “over-engineered” power supply
and advanced Class AB output circuit design. Wide-bandwidth
output devices assure detailed, transparent high frequency
response.
Construction and Quality Control
The HD2 is built exclusively in Crest’s own USA manufacturing
facility, with internal components selected for premium quality
and proven durability. Each modular subassembly is pre-tested,
and the assembled HD2 receives a rigorous “hot room” burn-in
before thorough final checkout on precision test equipment.
HD2 Features
• Crest’s legendary “overbuilt” power supply
• Toroidal power transformer
• Latest generation of high-speed, wide-bandwidth output
devices
• Twin Tunnel Cooling with back-to-front air flow
• Dual, variable speed DC fans
• Massive, extruded aluminum heat sinks
• Balanced XLR and 1/4-inch (TRS) inputs
• 5-Way binding post outputs
• Stereo/Parallel/Bridged Mono mode selector switch
• Ground lift switch
• TourClass
®
protection circuits:
- ACL (Active 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.
- AutoRamp gradually increases gain to attenuator setting
level when amplifier is turned on.
- TourClass also includes comprehensive thermal manage-
ment, and short circuit, DC voltage, turn-on/off transient,
current inrush and sub/ultrasonic input protection.
• Input sensitivity selection
• Recessed, stepped attenuators
• Front panel magnetic circuit breaker switch
• Modular construction
• Three-year warranty (parts and labor)
Ch A
Ch B
Protect
Active
Clip
Signal
Protect
Active
Clip
Signal
-6
-10
-15
-30
-80
-3
-1
0dB
-6
-10
-15
-30
-80
-3
-1
0dB
HD2
POWER AMPLIFIER
Power Specifications 8Ω Stereo 4Ω Stereo 8Ω Bridged
1kHz, 0.01% THD+N 150W 250W 500W
20Hz-20kHz, 0.1% THD+N 150W 200W 450W
Figures are Watts per channel, both channels driven.
4Ω Stereo HD4 HD6 HD9 HD12 HD18
1kHz, .01% THD+N 435W 600W 900W 1200W 1800W
20Hz-20kHz, 0.1% THD+N 400W 500W 800W 1100W 1700W
Power Specifications:
Other HD Series Power Amplifiers

Crest Audio HD2 Specifications

General

Brand	Crest Audio
Model	HD2
Category	Amplifier
Language	English

Summary

Product Description

Construction and Quality Control

HD2 Features

Audio Specifications

Stereo Power Output

Details stereo power output at 8 ohms and 4 ohms, for 1kHz THD+N and 20Hz-20kHz THD+N.

Bridged Mono Power Output

Specifies the bridged mono power output at 8 ohms for 1kHz THD+N and 20Hz-20kHz THD+N.

Frequency Response

Defines the amplifier's frequency response at 1W/8 ohms and its power bandwidth at rated power.

Input Sensitivity and Gain

Covers input sensitivity (standard and configurable options) and voltage gain settings.

Noise and Crosstalk

Provides specifications for hum and noise levels and channel crosstalk at full power.

Thermal and Power Characteristics

Details thermal emissions, idle current, and power current draw figures for various operating conditions.

Controls and Indicators

Front Panel Controls

Describes the front panel controls including attenuators and LED indicators.

Rear Panel Controls

Details rear panel controls such as signal ground lift and mode select switches.

Construction and Dimensions

Chassis and Construction

Outlines the steel chassis construction, rack mounting capabilities, and warranty information.

Physical Dimensions and Weight

Provides the amplifier's physical dimensions (H x W x D) and weight specifications.

Architects & Engineers Specifications

Power Output Requirements

Specifies minimum power output requirements for stereo and bridged mono modes at specified impedances and THD.

Protection Circuitry

Details required protection features including output short circuit, thermal overload, and DC voltage protection.

Cooling System

Describes the cooling system with rear panel variable speed DC fans and back-to-front airflow.

Input and Gain Configuration

Specifies input sensitivity, configurable gain options, and input impedance requirements.

Front Panel Features

Lists required front panel indicators (Active, Protect, Signal, Clip) and controls (attenuators).

Rear Panel Features

Details rear panel connectors (XLR/TRS) and switches (ground lift, mode selector).