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The input that is not connected to the preamplifier may be used as an output to a
second amplifier for power bi-amp applications. Before proceeding with such an
installation, you should consult your dealer or Krell.
The KSA-150 and KSA-250 are shipped with shorting pins in the XLR inputs.
These pins must remain in the XLR inputs if the units are to operate in the single-
ended mode. These pins must be removed to connect either unit for balanced
operation. The shorting pin connects pins 1 and 3 and grounds the inverted input.
The wiring to and from the amplifier, and all components in general, should be
arranged in a neat, organized manner. Specifically, AC wires should be
separated from audio wire. This insures the avoidance of hum or the introduction
of other unwanted noise into the system.
It is always preferable to run long interconnect cables to the amplifier and to keep
speaker cable length to a minimum. Speaker cable does add impedance
between the speakers and the amplifier, regardless of the wire gauge. All Krell
amplifiers will drive the lowest impedances with ease. When impedance is added
in any significant amount, (for instance with excessive cable length) amplifier
power is literally wasted in driving the cable, thereby reducing the maximum
power that can be delivered to the speakers.
The feet on the KSA-150 or KSA-250 can be used three different ways. They are
made from machined Delrin and are supplied with separate rubber bottoms and
mounting screws. The rubber bottom can be screwed into the Delrin for the
protection of fragile surfaces such as hardwood floors or furniture. For use on
rugs or carpeting, using the feet without the rubber bottoms is recommended.
You may purchase, from your authorized dealer, a set of Acoustic Mass
Dampers (AMDs). AMDs are custom-machined stainless steel feet fitted with a
threaded insert and a washer made from acoustically absorbent material. When
threaded into the Delrin feet, the AMS will decouple the amplifier from vibrations
present on the surface where the unit is installed.
Once the amplifier is in place,
and turned off,
you can begin to connect the
interconnect and speaker cables. The preamplifier should be off, with the level
fully attenuated (turned down). All other sources should be off. The two sets of 5-
way binding posts for each channel’s output are wired in parallel to allow easy bi
wiring.
You may now connect the AC.
E. OPERATION
Activate the system by turning on the source components and preamplifier with
the volume fully attenuated (turned down). The amplifier must always be turned
on last. Just after turn-on, a soft click will be heard. This is the main power relay
