Universal Audio UAD Plug-Ins ver.7.5 - Manual (Page 433)

UAD Powered Plug-Ins Manual - 433 - Chapter 44: SPL Transient Designer
The SUSTAIN
Control Circuitry
The SUSTAIN control circuitry also plays host to two envelope generators. The
envelope tracker Env 3 again follows the original waveform. The envelope
generator Env 4 maintains the level of the sustain on the peak-level over a
longer period of time. The control voltage of the VCA is again derived from
the difference between the two voltages. Sustain amplitude is increased for
positive SUSTAIN settings and reduced for negative settings.
Figure 138 on page 433 illustrates the original waveform and the envelope
creation to control the SUSTAIN processing. Envelope generator Env 1 fol-
lows the original waveform, Env 2 is generated with prolonged sustain.
Figure 139 on page 433 shows the difference between Env 4 and Env 3 that
defines the control voltage of the VCA.
Figure 138. SPL Transient Designer Sustain Envelopes
Figure 139. SPL Transient Designer Sustain Control Voltage