4
O W N E R ’ S M A N U A L
MODEL 500 AMPLIFIER
F E A T U R E S
The MODEL 500 subwoofer amplifier was designed to offer performance, value, and flexibility. It
incorporates a 500W class A/B amplifier utilizing the patented BASH technology for high electrical efficiency.
4 independent controls offer flexibility to integrate nearly all subwoofers with the main speakers and the
listening environment. (Instructions for fine tuning these controls are described in a later section of this
manual.)
The continuously-variable low pass filter network is adjustable from 40Hz to 120Hz and can be bypassed if it
is preferable to use an external filter or one located in an outboard receiver or processor.
The continuously-variable phase circuit is adjustable from 0 to 180 degrees to finely integrate the subwoofer
with the main listening speakers.
The MODEL 500 incorporates a unique continuously-variable subsonic filter that is adjustable from 20Hz to
35Hz that preserves the amplifiers power for only bass frequencies that are reproducible by the subwoofer.
It also helps to protect the subwoofer from being overdriven and can help to reduce distortion by reducing
extreme woofer excursion.
A defeatable Auto-power mode turns the amplifier on automatically when a signal is detected. The Auto-
power mode can be defeated if it is desirable to use a remote AC circuit to control the amplifier power.
Dual subwoofer outputs allow multiple woofers to be connected to the same amplifier without having to
resort to pigtails, wire nuts, or specialized connectors.
The Model 500 incorporates stereo Line Level inputs and outputs that permit the amplifier to be connected
between a preamplifier and amplifier without the need for Y-connectors. The Line-Level inputs also
incorporate a buffered internal summing network so that a mono signal is derived from the left and right
channels while maintaining the stereo signal integrity for the main stereo speakers.
A double-insulated isolated-ground electrical supply prevents electrical ground loops and reduces the noise
floor of the entire audio system.
Model 500 amplifier shown with rack ears attached.