Solid State Logic B-DYN 611B 500 Series Compressor/Limiter

The 4000 B Dynamics (B-DYN) 500 series module from SSL takes the dynamics processor found in the channel strip of the SL 4000 B console and puts it into 500 Series format. Released in 1976, the SL 4000 B was the first commercially available console from Solid State Logic and famously used in The Stone Room at Virgin’s Townhouse Studio (London), Le Studio (Montreal) and Record Plant (LA). It was responsible for countless iconic records, including Phil Collins’ “In the Air Tonight” and Peter Gabriel’s “Intruder,” both of which feature characterful compression on drums and vocals. The B-DYN allows you to add heavily colored, grabby, saturated compression from one of the rarest studio consoles ever made to your production toolkit.

Compressor/Limiter

The compressor/limiter features stepped compression ratios of 2:1, 4:1, 10:1 and “DS.” The DS setting is a fixed 10:1 with an additional sidechain filter. When out, the compressor is bypassed. Whenever a signal exceeds the threshold level set by this control, the compressor will start to act at the ratio set by the Ratio control. The Threshold and Ratio controls also provide automatic make-up gain. A 6dB/octave 185Hz high-pass filter in the compressor sidechain helps reduce bass pumping effects. Switched/fixed release ranges from .2 ms to 1.6 ms with additional DS and Auto release options.

De-Ess (DS) Mode

By setting Compressor Ratio and Release controls to ‘DS’ the B-DYN module is optimized for reducing sibilance (de-essing). The De-Ess is a 10:1 ratio with filtered S/C input signal, delivering broadband compression triggered by sibilance. The DS release is automatically varied in response to the processed signal between release rates of 30 & 50 ms. This is a much faster minimum release than you would normally expect from an SSL Dynamics section. The attack time is also reduced to a fast 2 ms, slightly faster than the E-Series Dynamics module on its fast setting.

Gate/Expander

The B-DYN Gate/Expander section can act as a 20:1 gate or as a 2:1 expander when the EXP button is pressed. Its attack time is a fast 0.2 ms. RANGE controls the maximum amount of gain reduction applied by the Gate/Expander. When set to “out,” the gate/expander is bypassed. THRESH sets the threshold above which the the gate/ expander will be opened, while RELEASE sets how long the signal remains audible after the Gate/Expander closes. EXP switches the gate to expander mode with a gentle curve, for subtler control of level below the threshold.