Lexicon PCM 42 - Rear Panel

2.2 REAR PANEL
Figure 2.2 — PCM 42 REAR PANEL
A. POWER CONNECTOR
The POWER connector accepts standard IEC power
cords. Before plugging in the AC cord and applying
power, check the adjacent d plate to ensure that the
set operating voltage matches that of the AC mains.
B. VCO REMOTE JACK
The VCO input jack allows remote operation of the
MANUAL VCO-SWEEP control by means of a foot con-
troller (optional), or an externa! control voltage (range O
to +10 Volts; O Volts = maximum delay, + 10 Volts
= minimum, linear over a range of 3:1). The VCO jack
accepts a standard 1/4” phone plug for control
voltages, or a stereo tip/ring/sleeve plug when used
with the optional foot controller (Lexicon A-CP-41 Foot
Pedal). When the plug is inserted, the MANUAL VCO-
SWEEP is bypassed and has no effect.
C. BYPASS SWITCH JACK
The BYPASS function provides a means of quickly
switching the delay signal out of the MAIN OUTPUT
mix, while at the same time killing the feed to the delay
circuitry itself. The BYPASS jack accepts a 1/4” phone
plug and the BYPASS is activated when the tip of the
plug is shorted to the sleeve, or when a TTL logic ‘0" is
present at the tip.
D. co REPEAT SWITCH JACK
The INFINITE REPEAT function is activated by a
momentary switch closure or the falling edge of a TTL
compatible clock pulse. The unit remains in repeat
mode until another closure or pulse arrives OR the front
panel INFINITE REPEAT pushbutton (Fig. 2.1, J) is
released from a depressed position. The BYPASS func-
tion and the INFINITE REPEAT mode may be controlled
with a single Lexicon A-FS-41 Dual Footswitch
Assembly, or any combination of one latching
(BYPASS) and one momentary-contact (INFINITE
REPEAT) switch.
E. CLOCK OUTPUT JACK
The CLOCK OUTPUT jack provides a TTL-compat-
ible square wave output suitable for clocking many
automatic rhythmic devices and sequential controllers.
The rate of the clock is a fraction of memory Capacity at
the current sampling rate, programmable from the front
panel. This allows synchronization of external devices
to the delay period. (See Sections 3.6 and 4.3.2.)
F. DELAY OUTPUT JACK
The DELAY OUTPUT is an unbalanced tip/sleeve
jack carrying the output of the delay line at line level,
unmixed with any of the direct signal. (See Sections 3.2
and 4.4.)
G. DIRECT OUTPUT JACK
The DIRECT OUTPUT is an unbalanced tip,’sleeve
jack which carries only the input signal after preampli-
fication. This signal is at system line level.
H. INPUT JACK
The INPUT jack is a balanced, differential input which
accepts a 1/4” tip/ring/sleeve phone plug; unbalanced
sources can be accommodated by simply substituting a
tip/sleeve phone plug. A high input impedance allows
the PCM 42 to interface with either low or high im-
pedance sources.
|. GAIN SWITCH
The GAIN Switch matches the PCM 42's ‘nput sen-
sitivity to the signal source. Engaging the switch in-
creases sensitivity by 20 dB for sources such as electric
pickups, high-output microphones, and some electronic
instruments.
J. FEEDBACK CONTROL JACK
The FEEDBACK CONTROL jack provides two distinct
functions. When used with a tip/ring/sleeve plug and a