UAD Powered Plug-Ins Manual v5.2 - Just Music

Warning: Due to these differences in input structure, cut and pasting of
full-to-SE and SE-to-full presets may cause noticeable differences in gain. Keep
hold of the master fader!
Drive/Gain LED
Envelope
The Drive/Gain multicolor LED indicates the plug-in signal level
just after the Drive/Gain control. The Drive/Gain LED operates
when the plug-in is in Bypass mode, but not when Power is off.
The Envelope controls (Envelope knob, Smooth/Fast switch) closely mimic the
controls of the MF-101 Moogerfooger. However, UA has broadened the
sonic palette with a negative range allowing unique negative envelope
effects.
The cutoff frequency of UAD Moog Filter can be modulated by the amplitude
of the signal coming into the plug-in. This function is typically called an “envelope
follower” or “auto wah” because the cutoff frequency “follows” the
signal input level. The amount and speed of the envelope response can be adjusted.
The envelope knob determines how much the filter cutoff frequency is affected
by the signal input level. Positive and negative values are possible. Positive
values increase the filter cutoff as the input amplitude increases (the filter
opens as the signal gets louder). Negative values decrease the filter cutoff as
input amplitude increases (the filter closes as the signal gets louder).
The greater the value (either positive or negative), the greater the amount of
filter modulation (the cutoff frequency range is increased with greater values).
Tip: Click the knob label (“ENVELOPE”) to return the value to zero.
Envelope LED
Smooth/Fast
This LED indicates the relative peaks of the control envelope. The
envelope LED does not illuminate when the plug-in is in Bypass mode
or when Power is off.
This toggle switch determines the release time of the control envelope. In
Smooth mode, the release time is 200 milliseconds. In Fast mode, the release
time is 40 milliseconds. In both modes, the attack time is 25 milliseconds.
In typical applications, Fast mode is useful on percussive sounds, while
Smooth mode is better suited to sounds with longer and/or uneven decays.
UAD Powered Plug-Ins Manual - 354 - Chapter 39: Moog Multimode Filter