Delay; Design - Lexicon PCM 90 - REV 1 User Manual

PCM 90 User Guide

Delay

You can set and display delay val-
ues in units of time, or with tempo
values. Press Up and Tempo simul-
taneously to toggle between these
two options. When time units are
selected, delay times are set and
displayed in milliseconds or seconds
(from 0ms to the maximum available
delay for that parameter). When
tempo values are selected, delay
values are set and displayed as a
ratio of echoes to beats (from 24:1 to
1:24). This will automatically syn-
chronize the delay to the current
tempo (MIDI, Internal, or TAP — see
Tempo Mode in Chapter 2.) For ex-
ample, a delay setting of 1:2 (1 echo
for every 2 beats) will produce half-
note delay rhythms synchronized to
the current tempo.

Design

3-12
In each the Random Hall and Rich Plate algorithms, a Delay row contains
parameters for delay, feedback and level settings of each voice. Press Load/
to cycle through selections.
Mstr Dly, Dly L, Dly R
These controls provide delay voices to the left and right channels. The delays
are routed to the output (through the Lvl controls) and also through a feedback
path. The master delay control allows you to simultaneously change the delay
times of both voices. The available range is from 0-200%. This provides a simple
way to expand or close in the voice delay times. If a voice's delay time is set to
500ms, changing the setting of Mstr Dly to 200% will change the delay time to
1.000sec. Setting this parameter to 0% is an easy way to set both delays to 0
from a single control.
When display of values in BPM has been selected, these are set as fractions of
a beat. The smallest fraction is 1/24th beat. Delay times can also be tempo
modulated.
Mstr Lvl, Lvl L, Lvl R
These controls modify the levels of the delay voices (Dly L and R) as they are
routed to the output. The range of the left and right controls is from Full (0dB),
to -85dB, to Off. Mstr Lvl provides grouped control from 0-100%. With low or
moderate settings, small changes in Mstr Lvl may not have any effect.
Mstr Fbk L, Fbk R
These controls modify the levels of the delay feedback path. The range of the
left and right controls is from -100% to +100% in 1% increments. Mstr Fbk
provides grouped control from 0-100%. With low or moderate settings, small
changes in Mstr Fbk may not have any effect.
The Design row, available in every algorithm, contains parameters that affect the
structural aspects of the reverb effect. In the Chamber/Room algorithm, indi-
vidual Design rows are available for Effect A and B.
Size
Size sets the rate of build-up of diffusion after the initial period (which is
controlled by Diffusion). The Size control changes a reverb sound from very
large to very small. Generally, you should set this control to approximate the size
of the acoustic space you are trying to create, before adjusting anything else.
The size in meters is roughly equal to the longest dimension of the space. Audio
is temporarily muted when Size is changed.
Diffusion
A Diffusion control is provided in all algorithms. It controls the degree to which
initial echo density increases over time. High settings of Diffusion result in initial
build-up of echo density, and low settings cause low initial build-up. Echo density
is also affected by Size; smaller spaces will sound denser. To enhance
percussion, use high settings of Diffusion. For clearer and more natural vocals,
mixes, and piano music, use low or moderate settings of Diffusion. Note that, at
some extreme input levels, high settings of Diffusion may trigger the overload
indicators on the headroom display.
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