Punch, color, weight, and tone. Two channels of iconic diode bridge compression – straight from the Shelford Channel.

Since the early 1970s, Rupert Neve’s vintage 2254 and 33609 diode bridge compressors have been revered for the punch & thickness they bring to drums, instruments, and the mix bus. Originally developed for the acclaimed Shelford Channel, the Shelford Diode Bridge Compressor captures the soul of these coveted compressors while providing a host of modern updates, including advanced timing control, significantly lower noise, fully stepped controls throughout, higher voltage power rails, and internal parallel processing capabilities.

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.

Features

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.

Specifications

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

PRODUCT DIMENSIONS

• 19” (48.3 cm) x 9” (22.9 cm) x 1.75” (4.4 cm)

SHIPPING DIMENSIONS

• 24” (61 cm) x 13” (33 cm) x 4” (10.2 cm)

SHIPPING WEIGHT

• 10 lbs. (4.5 kg)