“…holy smokes. Not kidding…the best compressor I’ve heard in 30 years of mixing.”
What is diode bridge compression?
Where the VCA compressor found in the
Master Buss Processor provides unmatched clarity, the weighty, harmonically rich tonality of diode bridge compression can be essential in pushing key sources like vocals, electric guitars, bass and drums to the forefront of a mix.
By understanding the limitations of vintage units like the legendary 2254 & 33609, painstaking effort was taken to reproduce the unique tone of these classics while improving the noise floor & accuracy, expanding inflexible time constants, adding full wave sidechain detection for improved dynamic response, and widening the range of threshold and ratio controls.
Delivering the powerful sound of these iconic designs with enhanced flexibility for the modern age, the Shelford Diode Bridge Compressor is a dynamic tool equipped to make a bold statement on virtually any mix or track.
HOW DOES IT SOUND?
Click below to hear the Shelford Compressor on a variety of sources.
We recommend listening with headphones or on a good pair of monitors.
“A diode bridge is a very unique sound characteristic compared to other types of compressors. It is possible to create a cleaner sounding diode bridge than we have here, but we were after a particular flavor of harmonic content. As soon as you hear the sound, you know exactly what it is.”
—
Dennis Alichwer
Engineering Manager, Rupert Neve Designs
Classic Diode Bridge Tone
Capture the punchy, larger-than-life tone used on countless hit records for the last 50 years.
Advanced Timing Controls
Custom-shape your compression envelope with the unified timing control, which enables a much wider range of responses than vintage units or clones.
Custom Transformers and Class-A Line Amplifiers
Vintage warmth meets the improved headroom and precision of Rupert Neve’s updated transformer-coupled line stages.
31-Position Detented Controls
Accurately recall and match your settings with precision and speed.
Built-In Parallel Compression
Internal blend control enables you to subtly dial in more dramatic compression settings for color as desired.
Full-Wave Sidechain Detection
Enhanced from the vintage units’ half-wave design, the updated sidechain detector provides substantially more accuracy.
Stereo Linking
Run your compressors in either dual mono or stereo configurations.
Internal Universal Power Supply
EIC connection for world-wide AC power from 90-240V embedded in the 1U rack-mountable chassis.
REVIEWS
“…and holy smokes. Not kidding…the best compressor I’ve heard in 30 years of mixing.”
Kevin Lemoine
Green Day, Social Distortion, Iggy Pop
“The new 5254 retains the signature ‘clamp’ of the beloved 2254 while being more more flexible thanks to its expanded parameters. It was exactly what we needed to glue together our mixes on the latest all-analog Panic! At The Disco recordings.”
Jake Sinclair
Weezer, Fall Out Boy, 5 Seconds Of Summer
“It has all the fabulous tone and character of the old-school diode bridge compressors, with a much lower noise floor and far greater control options. The 5254 is a unique-sounding modern classic that stands out to me as one of the most sonically pleasing, versatile new compressors I have heard in many years.”
“With slow and gentle settings, I found the 5254 sounded pleasantly clean — certainly cleaner than I remember the original 2254 being — but there is still a subtle hint of harmonic richness and character there, and it develops quite obviously with stiffer ratios, faster timings and higher signal levels. This all makes it a little more versatile than the original 2254 and it will undoubtedly have applications on a range of sources, as well as for group and master bus compression.”
“It’s one of those devices that make everything you run through it sound better. It adds weight and richness while remaining useful even at extreme settings. The diode bridge does something quite different to the audio than other compressor types and I suspect that if you add one of these to your studio, I’d quickly become an essential tool and permanent fixture.”
“I’ve always been a huge fan of the 2254, and now the 5254 gives me all of that vibe, with a lot more detail and control. I’ve tried it on pretty much all the individual instruments you might have in a mix…and it was really exceptional on the mix buss.“
John O’Mahony
Matt Maeson, Sara Bareilles, Vance Joy, Metric
“When I first heard the Shelford Channel, I fell in love again with the diode compressor and knew I was going to need more of the Shelfords just for the compressor alone. Everything I ran through the diode bridge sounded better, from drum buss, bass, electric guitar, vocals.”
Brian Foraker
Heart, Soundgarden, Bad Company
“After working on a vintage Neve console for 10 years, it’s exciting to hear the Shelford sound like a 1073 and 2254 are supposed to, but without all the baggage.”
Mitch Dane
Jars of Clay
“…a freaking 2254, which is the best compressor on the planet. So this is an updated version of that, and it’s got a Blend control so I can use it in parallel, which is a colossal pain in the butt to do with the old compressors, and now I can just do it with the twist of a knob – like, you know? Marry me!”
F Reid Shippen
Ingrid Michaelson, Kenny Chesney, Dierks Bentley
SPECIFICATIONS & DOWNLOADS
XLR LINE INPUT TO XLR LINE OUTPUT
Compressor Bypassed.
zSource = 40 Ohm Balanced
INPUT IMPEDANCE
10K Ohm
OUTPUT IMPEDANCE
40 Ohm
MAXIMUM INPUT LEVEL
+4 dBu Selected: +26.7 dBu typical
MAXIMUM OUTPUT LEVEL
+26.7 dBu typical
NOISE
10 Hz - 120 kHz: -104 dBu typical
FREQUENCY REPONSE
10 Hz to 120 kHz: +/- 0.25 dB typical
THD+N
From 22 Hz - 22kHz BW.
@ 1 kHz @ Maximum Level: 0.0008% typical
COMPRESSOR NOISE
From 22 Hz - 22kHz BW.
zSource = 40 Ohms Balanced
NOISE
@ 0 dB Make-up gain: -84.5 dBu typical
@ +20 dB Make-up gain: -64.5 dBu typical
COMPRESSOR TIMING CONSTANT MEASUREMENTS
Note: TIMING measurements represent the full range between 1.5:1 and 8:1 ratio and FAST mode
FAST – Attack 250 μS - 2 mS // Release 100 mS - 200 mS typical
MF (MEDIUM FAST) – Attack 1 mS - 5 mS // Release 100 mS - 200 mS typical
MED (MEDIUM) – Attack 3 mS - 18 mS // Release 350 mS - 700 mS typical
MS (MEDIUM SLOW) – Attack 5 mS - 40 mS // Release 600 mS - 1 S typical
SLOW – Attack 10 mS - 80 mS // Release 800 mS - 1.5 S typical
AUTO – Attack 5m S - 40m S // Release T1 400-900 mS, T2 1-2 S typical
UNIT DIMENSIONS
1RU: 19” W x 8.25” D x 1.75” H
(48.3 cm W x 21 cm D x 4.5 cm H)
UNIT WEIGHT
8.5 lbs. (3.9 kg)
SHIPPING DIMENSIONS
24” W x 13” D x 4” H
(61 cm W x 33 cm D x 10.2 cm H)
SHIPPING WEIGHT
10 lbs. (4.5 kg)
