Universal Audio UAD POWERED PLUG-INS ver.6.1 - Manual (Page 374)

UAD Powered Plug-Ins Manual - 374 - Chapter 36: Neve 33609 Compressor
Headroom Switch
The Headroom switch is provided to accommodate applications where high
amounts of gain reduction are not desired. Headroom simply lowers the in-
ternal operating level so that the plug-in is not “pushed” into gain reduction as
much.
Headroom can be set to 22 dB, 18 dB, or 14 dB. At 22 dB, signals will push
the plug-in into gain reduction (and more non-linearity and “good” harmonic
distortion) more easily. Set the switch to a lower value when less gain reduc-
tion and color is desired.
The numbers on the switch indicate where 0 dBFS falls relative to nominal +4
dBu. For example, with 22 dB of headroom, 0 dBFS corresponds to +4 dBu
+ 22 dB = 26 dBu. With 18 dB of headroom, 0 dBFS corresponds to +4 dBu
+ 18 dB = 22 dBu. The headroom selected will cause the plug-in to behave
as though it were a hardware 33609 connected to a nominal +4 dBu inter-
face with the selected amount of headroom. Industry standards for most DAW
interfaces are +14 dB and +18 dB headroom. The +22 dB setting approxi-
mates some analog mixing environments, and allows the entire useful dy-
namic range of the 33609 to be exercised.
The following settings are application guidelines for the Headroom switch:
22 dB
Typical starting point for individual track inserts where maximum gain reduc-
tion is desired. This setting is equivalent to having a real hardware 33609
connected to a +4 interface with +22 dB headroom.
18 dB
Typical starting point when used on a buss or group where nominal gain re-
duction is desired. This setting is equivalent to having a real hardware 33609
connected to a +4 interface with +18 dB headroom.
14 dB
Typical starting point for mastering where minimal gain reduction is de-
sired. This setting is equivalent to having a real hardware 33609 connected
to a +4 interface with +14 dB headroom.