Selector Switch - Peavey VX 1.5K Operating Manual

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BACK PANEL
HIGH Z INPUT JACKS (6)
Two parallel (bridged) input jacks are provided for each channel. This allows for one to be used as a conven¬
tional input, and at the same time the other to be used as a "line out" (Y-cord) to connect to another input jack on
this amplifier or other amps/equipment. These 1/4" jacks are not "chassis grounded" and when used will provide
a QUASI-BALANCED input capability due to a unique "ground loop" elimination circuitry associated with the
inputs. This feature will normally allow "hum free" operation when relatively short 1/4" cable patches are made
between the various jacks on this amp and other jacks on various other equipment that share the same rack with
this amplifier. This QUASI-BALANCED capability is automatic and it can not be removed from the system's
circuitry.
LOW Z INPUT (7)
A conventional three-pin, female XLR input jack is provided and may be used as the channel input. When the
(PL-2) line balancing transformer is not used this XLR input becomes QUASI-BALANCED with pin #3 as the
positive input (connecting to the tip of the 1/4" input jacks above), pin #2 as the negative input (connecting to the
floating sleeve of the 1/4" input jacks above), and pin #1 going to the internal power amplifier ground. When the
(PL-2) line balancing transformer is used, this XLR input becomes fully TRANSFORMER-BALANCED (Pin
#3 positive, pin #2 negative, pin #1 ground). (See the PL-2 SELECTOR SWITCH section for details on related
settings.)
PL-2 SELECTOR SWITCH (8)
This switch is used in conjunction with the PL-2 transformer to allow the LOW Z INPUT to function with or
without a PL-2 module being inserted in the receptacle. The "OUT" position of this switch selects the
QUASI-BALANCED mode of operation for the LOW Z INPUT (XLR jack), and routes the input signal directly
to the HI Z INPUT JACKS. In this position the HI Z INPUT JACKS may be used as outputs after the LOW Z
INPUT to allow patching this signal to another input on this amp. Normally, in this switch position, a (PL-2)
transformer is not present ("OUT") in the transformer receptacle; however, if one were "IN" the receptacle, the
LOW Z INPUT would still be QUASI-BALANCED. It becomes fully TRANSFORMER BALANCED only
when the IN switch position is selected. Notice this is a very effective means to "test" for the necessity of a
line-balancing transformer. The "IN" position of the switch routes the signals from the XLR jack through the
(PL-2) line-balancing transformer, thereby selecting the TRANSFORMER BALANCED mode of operation for
the LOW Z INPUT. In this position the HI Z INPUT JACKS may be used as outputs after the line balancing
transformer to patch the signal to another input jack on this amplifier or other amps/equipment. If die "IN"
position is selected without a (PL-2) line-balancing transformer "IN" the receptacle, the LOW Z INPUT will be
rendered inoperable.