-3-
Operating Your S/PS-140
Loudspeaker Selector Switches
Once you have connected up to four pairs of loudspeakers to the S/PS-140, you can turn on any pair by
simply pressing the designated selector switch for the speakers you want to hear.
Speaker Impedances and the Amplifier Protection Switch
When switching on multiple pairs of loudspeakers, you need to be aware of your amplifier's capability of
safely driving all of the selected speakers. Most power amplifiers can easily drive impedances as low as
4
Ω
per channel. However, as you try to drive impedances below 4
Ω,
the amplifier may go into
protection or even fail. You should use the protection switch whenever you connect any more than two
pairs of 8
Ω
loudspeakers to your S/PS-140.
The speaker protection selector switches in a 60 watt non-inductive resistor bank that keeps the amplifier
from "seeing" impedances below 4
Ω
. This provides protection for amplifiers with up to 250 watts per
channel from damage when driving multiple pairs of loudspeakers. With the protection switch engaged,
you will experience a slight reduction volume from the loudspeakers.
S/PS-140 Specifications
Protection Wattage:
Internal 60 watt non-inductive resistors protect amplifiers up to 250 watts per
channel.
Dimensions:
9 1/2" W x 1 3/4" H (2" with feet) x 7"
Net Weight:
2 1/2 lb.
Specifications subject to change or improvement without notice
S / P S - 1 4 0 L o u d s p e a k e r
2
1
Protect
4
3
L o u d s p e a k e r S e l e c t o r s
A m p l i f i e r P r o t e c t i o n