Lexicon PCM 42 - Non-Audio Remote Control! Functions

WARNING
THE PCM 42 OUTPUTS ARE PROTECTED
AGAINST SHORT CIRCUITS, BUT SHOULD
NEVER BE CONNECTED TO SIGNAL
SOURCES.
AUXILIARY INPUT AND OUTPUT LEVELS
The DIRECT an
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1d DELAY outputs, as weil as the delay
3.5 NON-AUDIO REMOTE CONTROL
FUNCTIONS
BYPASS LAT CHE }
SWEEP
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are nominal ally 3.5 Vrms (+11 dBV) for
full input level.
The audio patch points connected to the tips of the
audio control jacks are impedance, line level (+ 11
dBV maximum), single-ended
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Figure 3.1 — FOOT PEDAL DIAGRAM
Three rear panel phone jacks permit remote control of
the BYPASS, INFINITE REPEAT, and VCO functions.
The Lexicon A-FS-41 Dual Footswitch Assembly may
be used to contro! the first two functions, and a Lexicon
A-CP-41 Foot Pedal for VCO control: or any of a
number of common foot switches or controls may be
substituted. You can also construct your own controller
according to the information provided below.
BYPASS SWITCH JACK (Fig. 2.2, C)
In BYPASS mode, two things happen: the delayed
audio is cut out of the MAIN OUTPUT MIX, and the in-
put to the delay line is interrupted. The BYPASS jack
accepts a standard 1/4” tip/sleeve (mono) phone plug,
and is activated either by a switch closure which
grounds the tip to the sleeve, or by a low-going (logic
“OOP TEL aera Opening the connection (or inputting a
logic ‘1’')'will turn off the BYPASS mode; we recom-
mend a latching footswitch for this function
INFINITE REPEAT SWITCH JACK (Fig. 2.2, D)
The REPEAT function allows permanent retention of
any sound stored in the delay memory. The REPEAT
jack accepts a standard 1/4” tip/sieeve phone plug; the
feature is activated either by a momentary switch
closure which grounds the tip to the sleeve, or by a low-
1
going TTL pulse. This mode ts cancelled by any subse-
quent momentary switch closure or pulse. Unlike
BYPASS, INFINITE REPEAT mode may also be con-
trolled from the front panel.
VCO REMOTE JACK (Fig. 2.2, B)
The VCO jack allows remote operation of the delay
sweep. It serves the same purpose as the front panel
MANUAL VCO- SWEEP control. idee a standard 1/4”
T/R/S phone plug is inserted in this jack, the front
panel MANUAL VCO-SWEEP ee is switched out
and the remote control is substituted. This function can
be controlled either by a potentiometer or by an external
voltage source with a range of 0 to +10 volts.
lf a potentiometer is used, it should have a linear
(rather than log or audio) taper. Values of 10k to 500k
ohms will work; 50k is preferred. The CCW end of the
potentiometer should be connected to the sleeve ter-
minal of the VCO jack, the CW end to the ring terminal,
and the wiper to the tip terminal. The remote control
will then function exactly as the MANUAL VCO-
SWEEP control does (i.e. CCW = X.5, CW = X2).
Voltage programming of the VCO function requires a
source with a range of 0 to + 10 volts, which could be a