Apogee Sound CA8000DEC User Instruction Manual - Page 7

Browse online or download pdf User Instruction Manual for Amplifier Apogee Sound CA8000DEC. Apogee Sound CA8000DEC 16 pages. Professional amplifier

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2.4 Auxillary Ground Lug

All CA8000D-Series amplifiers are equipped with a signal ground lug. This lug is NOT intended as a primary

AC power ground, which instead should be connected to the building ground by means of the power cord.

The ground lug is electrically tied to the chassis and can be useful as a means of reducing the chassis

ground impedance, thereby eliminating ground loops between devices when setting up a sound system.

One common practice is to tie together all the ground lugs of all devices that share a rack or housing, then

to make one point of connection between the ground wire and the signal ground. There are other methods

that can be effectively utilized, depending on the type of AC power distribution and other factors. Please

consult our Technical Department for more information. In all cases, we recommend the use of heavy gauge

wire (#14 AWG or larger) when auxiliary ground connections are utilized.

This filter cuts off frequency components below 25 Hz. When powering small and medium format speakers,

it is useful as an aid to reduce excessive cone excursion. Also, when the amplifier is powering 70v or 100v

constant voltage systems, it can be used to reduce the likelihood of saturating the step-up and step-down

transformers by removing excessive low frequency content. The filter may be switched ON and OFF via

internal jumpers, one per channel. Technically, the filter is an 18dB/octave Butterworth with a corner

frequency of 25 Hz (see Figure 5.3).

CAUTION: Changes to the HIGH PASS FILTER settings require that the cover of the amplifier

be removed, potentially exposing the user to hazardous voltages inside the amplifier. There-

fore, all configuration work must be performed by a qualified service technician

The CA8000D-Series amplifier employs ANTICLIP limiters as part of an active protection system designed to

help increase the lifespan of the loudspeakers. The ANTICLIP circuitry constantly analyses harmonic distortion

at the amplifier's output and automatically reduces the input level in order to not exceed a predetermined

distortion index. CA8000D/E amplifiers are delivered with the ANTICLIP system set to a threshold of 1% THD

(Total Harmonic Distortion) which we refer to as 'hard limiting'. However, this value can be switched to a 'soft

limiter' that permits a max. of 5% THD. Each channel may be set to either soft or hard limiting, independently via

internal jumpers (see Figure 5.3).

CAUTION: Changes to the ANTICLIP settings require that the cover of the amplifier be removed,

potentially exposing the user to hazardous voltages inside the amplifier. Therefore, all

configuration work must be performed by a qualified service technician.

The OUTPUT section on the rear panel features Speakon connectors.

Whenever you need to operate the amplifier in BRIDGED mode, you must set the "STEREO/BRIDGE"

Switch to BRIDGE. The input signal is taken from the CHANNEL 1 connector and the signal output to the

loudspeaker is on pins 1+ and 2+ of the Speakon connector "OUTPUT1".

ATTENTION: Terminals 1+, 1- and 2+, 2- must only be used in STEREO operation and terminals 1+, 2+ in

BRIDGED operation. Other combinations would lead to poor output quality. Please make sure that the

resulting impedance of your installation, when the amplifier is operating in BRIDGE mode, is never lower

than 4 Ohm (8 Ohm recommended).

In all cases, the connection cable that joins the amplifier and the loudspeaker should be heavy gauge, high-

quality wire, kept as short as possible. We advise using a wire gauge of at least #14 AWG for lengths of

50 feet. For longer runs (over 50 ft.) the wire gauge should be increased to #12 AWG or larger. Ideally, multi-

stranded, oxygen-free copper cable is recommended for best results.

2. Installation