Rupert Neve Shelford 5051 Inductor EQ / Compressor - Manual (Page 8)

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“knows” right away that a gain change is required and there is an almost immediate response. This is
known, logically, as a “feed-forward” compressor. If the VCA control voltage is taken from the 5051
compressor output, (i.e. after the VCA) it cannot act immediately on the VCA because it has already been
modified by settings of the VCA and circuits through which it has passed. This is known as a “feed-back”
compressor. The two compression characteristics are quite different, with both the attack and recovery
ramps are changed. Almost all of Mr. Rupert Neve’s earlier designs were “feed-back”.
The way in which these modes change the dynamic performance can be seen in the above graph,
but the more interesting effects are noted by listening .“Feed-Back” produces a sweeter, warmer
sound but is not as accurate if you need to protect a transmitter, for example.
5051 Design Notes
The RND Model 5051 represents Rupert’s latest addition to the 5088 family. Comprised of a new
inductor EQ circuit with a heritage going back decades, and a compressor with elements from the
Portico II: Master Buss Processor, the 5051 can be configured within a 5088 console to deliver
exceptional tonal and dynamic control on each channel.
Traditional transformer coupled inputs and outputs are used for both technical performance reasons and
optimum musical reproduction. The primary signal path uses Class A gain blocks; using as few of these
as possible to get the job done. The input circuit uses one gain stage, as does the line driver output. The
compressor introduces one stage, the EQ introduces two stages, plus one more if the 18 dB / octave high
pass filter is engaged. By combining this minimalisitic design aesthetics with class-A gain blocks and
custom transformers, the 5051 provides the extraordinary performance and musicality expected from a
Rupert Neve design.
The EQ certainly invokes similarities sound-wise with some of Rupert’s classic EQ designs from the
seventies. The 5051 repeats history in using a custom tapped inductor and carefully selected capacitor
values to form the mid range equalizer band. The 5051 also uses inductors for the low and high EQ,
with the shelf curves and frequency choices based on Rupert’s vintage designs. While this method may
not be as variable as some of Rupert’s designs of the last 20 years, the “old ways” did have a “sound”
that has become rather known and sought after. The use of low-feedback, class-A gain blocks in each
EQ section are also an important contributor to the overall sound, preventing low level artifacts and
harshness from detracting from the tonal shaping. While these elements make the 5051 much like many
of Rupert’s vintage designs, the 5051 takes advantage of techniques that were not possible 35 years ago,
and should not be considered a clone of his earlier work. Rather, the 5051 is a culmination of Rupert
Neve’s years of experience, expertise, and highly discerning ears, giving this unit a strong sense of Mr.
Neve’s design heritage.
Both the high and low band can be switched from shelf to peak curves and offer 15 dB of boost or cut.
The high band can be switched from 8 kHz to 16 kHz, and the low band can be selected at 35 Hz, 60
Hz, 100 Hz or 220 Hz. The inductor based Mid Band offers 6 center frequencies; 200 Hz, 350 Hz, 700
Hz, 1.5 kHz, 3 kHz and 6 kHz. The Mid Band also has a “Mid Hi Q” switch to narrow the bandwidth
(increase the Q) of the filter. The 5051 includes an 18 dB / octave high pass filter with cutoff frequencies
on a button that toggles through “OFF, 60 Hz and 120 Hz” indicated by a blue or red LED respectively.
Additionally, the EQ can be switched Pre or Post the compressor. The 5051 also has two XLR balanced
inputs that can be selected from the front panel. This allows the user to have both a mic preamplifier
and line input from a DAW pre-patched and easily selectable.