7
DRAWMER
1978 O
PERATOR’S
M
ANUA
L
2 - COMPRESSION CHARACTER
Release Curve
Logarithmic / Linear
In its out position this is the classic log release as used on most compressors,
when engaged this changes to a linear release which means the initial release
isn't as fast but the total release time is the same for 10dB compression. This
gives a less aggressive sound, especially at fast release times.
Channel Link
Normal / Wide
Normally, Left and Right channels respond equally under compression.
When engaged, WIDE channel linking changes to partial summing of left and right channels before the side chain, to
produce a wider image under compression.
PGM
Off / PGM
This switch when engaged will introduce a second, slower release time in proportion to the density of program material
above the threshold. The effect is to reduce excessive 'pumping' under heavy compression.
Smooth
Off / Smooth
When engaged this adds extra circuitry which slows the initial release, which might otherwise introduce distortion at low
frequencies (i.e. bass guitar), when using fast release times.
3 - SATURATION
Level
0 to 10
Saturation adds a combination of second and third harmonics to the signal and can range from a subtle sweetening
effect up to gritty distortion. It can be used in conjunction with the compressor or stand alone. The V,U, meter backlights
start to become red as saturation becomes audible.
Unless excessive saturation is required for a particular effect, this control should be used with caution.
4 - SHAPING
On the 1978 the Shaping section is much more than the standard side chain E.Q. that most compressor’s would
incorporate, replacing any dulling of high frequency detail by simply adding gain, but a fully variable dynamic
process that works in conjunction with the compressor, giving more “bass’ and ‘brightness’ as and when it’s
required.
In addition, the shaping on the 1978 can be used in conjunction with an external sidechain via
the rear panel insert points to provide even more sidechain control.
L.F.
The Low Frequency controls are fully variable allowing complete and subtle adjustments to the perceived level
of bass, and the control of ‘pumping’ and ducking that occurs.
L.F. Frequency
Shelf - 60 / 125 / 250 / 500 Bell - 200 / 400 Hz
Sets the frequency that the L.F. Level control operates at, enabling the engineer to target a specific bass frequency.
L.F. Level
0 to 10
As the L.F. Level is increased the compressor’s side chain sensitivity to low frequencies is reduced, with the
result that less gain reduction is applied to those frequencies, creating the effect that the bass is louder. It also has
the benefit of reducing the ducking and pumping effect that occurs by high frequencies being 'pulled down' in sync
with the bass, helping to make mix compression much more affable.
H.F. Frequency
Bell - 3/ 6 Shelf - 2 / 4 / 8 / 16 kHz
Sets the frequency that the H.F. Level control operates at, enabling the engineer to target a specific high frequency.
H.F.
H.F. shaping is used to manipulate the high end of an audio signal so that it sounds more intimate, detailed and
transparent, but without making it sound harsh or introducing any noticeably unnatural artefacts. Cymbals are more
vibrant without becoming splashy, and vocals sound more open but without becoming sibilant. Being full range the
1978 will compress quiet high frequencies whenever the low frequencies are being brought under control, resulting
in a dulling of these high levels, and in the worst cases, pumping - it is here where the VH.F. controls are at their
most effective.
