1. Introduction
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Congratulations! You have chosen an expertly designed and manufactured professional power amplifier.
The CA8000D-Series Professional Amplifiers from Apogee Sound offer superb sonic reproduction,
exceptional reliability and rugged construction normally found only in amplifiers costing much, much more.
A CA8000D-Series amp is well suited to a wide range of applications; it is equally at home when used in
fixed installations or travelling under the harshest touring conditions.
In order to obtain maximum functionality, it is important to carefully read this manual before connecting and
using the amplifier. If any repair or maintenance task should ever be needed, please contact Apogee Sound
International. We want to be sure that your product is serviced by authorized professionals, so it will continue
to meet the highest standards of quality.
With the CA8000D-Series of amplifiers, Apogee has applied an innovative new concept to the world of
professional audio, that of the use of Switching Field Effect Transistors (Pat. # 89011155/4). The integration
of these devices for audio applications represents a definitive step forward, eclipsing the performance of
conventional amplifiers. The advantages are:
1) Significantly less heat production due to lower internal resistance than bipolar transistors. The lower
internal resistance also translates to a more powerful and solid bass response (note: conventional FETs
have an internal resistance that is four to seven times higher than switching FETs).
2) Superb sonic transparency, especially in the upper frequencies, due to the extremely high speed of the
MOSFET devices. This fact also reduces TIM (Transient Intermodulation Distortion) to very low levels.
3) SOA Contour Following Protection
The SOA is the Safe Operating Area of the FET output devices. A good protection system must keep the
currents and voltages within the transistors well within the safe operating area, or reliability will be seriously
compromised. However, determining the SOA is a complex function, as it varies with the operating temper-
ature. For example, at 80°C it is considerably narrower than at 25°C (a typical start-up temperature). Some
manufacturers use protection schemes that are conservative, compromising the performance of the com-
ponents; you get fair protection, but the performance remains mediocre. Others prefer to leave "dark" areas
between the safe operating area and the activation of protection, which is very risky.
By contrast, Apogee CA8000D-Series amplifiers use a unique SOA Contour Following System. This guar-
antees total protection of the amplifier at any output power, load, or operating temperature, as the intelligent
electronic circuitry permanently watches for changes in the safety area, adapting itself to any situation.
4) The best damping factor of any amplifier in its class.
In the CA8000D-Series, the typical output relays have been substituted with an electronic CROWBAR
system. This device shunts-to-ground the output signal in the case of voltages that could damage the
loudspeakers. By contrast, a relay introduces a mechanical contact in the path of the audio signal to
the loudspeakers. This mechanical contact results in an important reduction of the amplifier’s damping factor.
Over time, the relay contacts are prone to wear, further reducing the amplifier’s damping and general
performance. Although the use of premium quality relays may minimize the problems, eliminating them
altogether increases the damping factor as well as the long term reliability.
The CA8000D features an expansion slot at the rear panel which is specially designed for the integration of
a DLX24i processor module.
The stereo digital processor module DLX24i can be totally configured through System Control Manager
software. Its audio processing features make it a particularly versatile tool, including:
• Parametric equalizer, multiband • Polarity inversion
• Crossover with variable filter slopes • Signal generator
• Remote level control • Delay
Please contact your Apogee distributor should you wish to order an amplifier equipped with a DLX24i module,
as this is a factory installed item within the CA8000DX and CA8000DXE Models only.
