SSL Duality Channel Strip Gate

Gate/Expander

This section can act as a Gate or as a 2:1 Expander when the RANGE pot is pressed. The EXP LED indicates that Expand mode has been selected.

RANGE

Determines the depth of gating or expansion. When turned fully anticlockwise (Range = 0), the section is inactive. When turned fully clockwise, an attenuation range of greater than 40dB can be obtained.

THRESHOLD

Variable hysteresis is incorporated in the Threshold circuitry. For any given ‘open’ setting, the Expander/Gate will have a lower ‘close’ threshold to prevent ‘hunting’ artifacts. The hysteresis value is automatically increased as the Threshold is lowered. This is very useful in music recording as it allows instruments to decay below the open threshold before gating or expansion takes place.

REL/HOLD

This determines the time constant (speed), variable from 0.1- 4 seconds, at which the Gate/Expander reduces the signal level once it has passed below the threshold. Note that this control interacts with the Range control. This control also incorporates a switch which, when pushed, provides a fast attack time (100µs per 40db), instead of the normal linear attack time of 1.5ms per 40dB. The attack time is the time taken for the Expander/Gate to ‘recover’ once the signal level is above the threshold. When gating signals with a steep rising edge, such as drums, a slow attack may effectively mask the initial THWACK, so you should be aware of this when selecting the appropriate attack time.

HOLD

When this button is pressed, the release time is fixed at 150ms but the hold time can be varied between 0 and 4 seconds by adjusting the REL/HOLD pot.