Rupert Neve Designs 5254 - Dual Diode Bridge Compressor

Rupert Neve Designs 5254 - Dual Diode Bridge Compressor

The Rupert Neve Designs Dual Diode Bridge Compressor is based on the 1970s model, capturing the soul of the coveted compressor whilst providing modern updates including advanced timing controls, lower noise, fully stepped controls, internal parallel processing capabilities and more.

Diode Bridge Compression

The 5254 is specifically to provide a wide range of colours to impart unique personality and character to your tracks. This diode bridge compressor will impart weight, harmonically rich tonality that will effortlessly bring vocals, electric guitars, bass and drums to the forefront of a mix.

Rupert Neve Designs 5254

Based on the circuit found on the acclaimed Shelford Channel, the Dual Diode-Bridge Compressor greatly improves on old vintage units without sacrificing the tone. Starting with a substantially lower noise floor,

Further upgrades include a full-wave side-chain detection which delivers improved dynamic response as well as an increased range for threshold and ratio controls. All these modern appointments ensure the 5254 can reliably be used as a mixing or mastering compressor.

Improved timing constants

The 5254 replaces traditional attack and release times with a unified Timing control with six selectable settings ranging from Fast to Slow and Auto. In the first two modes, Fast and MF, the compressor will achieve better control of transients clamping down on percussive instruments and fast vocals. The next two settings Med and MS (Medium Slow) will provide a smoother compression letting through the original transients through. The last two settings Slow and Auto provide the smoothest of compression thanks to their use of complex non-linear release times, offering much more transparent operation.

The reason for these time constants rather than separate attack and release control lies in the fact that time constants in diode bridge compression vary slightly depending on different controls such as ratio, threshold, and source material. These dynamic shifts are at the heart of the personality of the Diode Bridge Compressor.

A Fast mode also increases the speed of each of the six settings providing faster attack and release for each mode, in effect doubling the number of time constants from six to twelve and providing additional tones.

The fastest settings will by nature impart far more colouration due to the inherent harmonic content generated by higher peak-to-peak control voltage ripple. Slower settings on the hand will provide reduced harmonic content and sound more transparent.

Parallel Compression

The 5254 includes a built-in parallel compression circuit with a simple Blend control. It is particularly useful in such a coloured compression as it is possible to inject smaller amounts of extreme compression to enhance the original signal with additional colour without sacrificing the natural aspect of the original source and keep its dynamic range.

Complete Control

The 5254 offers complete control over the original audio signal, offering the possibilities to affect, ratio, threshold, gain, side-chain insert, side-chain high-pass filter and the ability to link both channels.

The Ratio control includes six positions ranging from a subtle 1.5:1 all the way to 8:1 (including 2:1, 3:1, 4:1 and 6:1). The Threshold uses a 31-step control with a threshold level ranging from -25dBu all the way up to +20dBu, while the Gain control adds make-up output gain between -6dB up to +20dB.

The 5254 includes a variable Side-Chain HPF (S/C HPF) with a 12dB/octave and a frequency range between 20Hz and 250Hz, ensuring the compressor doesn’t respond unnecessarily by the powerful energy produced by low frequencies and lose energy. A Side-chain insert is also provided allowing the user to send the signal to external processing to further sculpt the signal before the compression. This can be used to duck the compressor to an external source or can be used to send the signal to an EQ for further fine-tuning of the compression response.

A Link switch connects the source voltage to both channels so that if a channel is triggered, both channels react equally. This is particularly useful to maintain a coherent stereo image throughout. In unlinked mode, one channel could be over-affected by a source, ducking the entire channel while the other remains unchanged creating unwanted imbalance.

Specifications

XLR Line Input to XLR Line Output (Compressor Bypassed) ZSOURCE= 40 Ω Balanced

• Input Impedance: 10 kΩ
• Output Impedance: 40 Ω
• Maximum Input Level (+4dBu Selected): +26.7 dBu typical
• Maximum Output Level: +26.7 dBu typical
• Noise (22 Hz – 22 kHz BW): -104 dBu typical
• Frequency Response (10 Hz to 120 kHz): +/- 0.25 dB typical
• THD+N @1 kHz @ Maximum Level (22 Hz – 22 kHz BW): 0.0008% typical

Compressor Noise Specifications

• Noise @ 0dB Make-Up Gain (22 Hz – 22 kHz BW): -84.5 dBu typical
• Noise @ +20dB Make-Up Gain (22 Hz – 22 kHz BW): -64.5 dBu typical

Compressor Timing Specifications

• Note: TIMING measurements represent the full range achievable between 1.5:1 and 8:1 ratio and FAST mode
• FAST Attack 250μS – 2 mS // Release 100mS – 200mS typical
• MF (MEDIUM FAST) Attack 1mS – 5mS // Release 100mS – 200mS typical
• MED (MEDIUM) Attack 3mS – 18mS // Release 350mS – 700mS typical
• MS (MEDIUM SLOW) Attack 5mS – 40mS // Release 600mS – 1S typical
• SLOW Attack 10mS – 80 mS // Release 800mS – 1.5S typical
• AUTO Attack 5mS – 40mS // Release T1 400-900mS, T2 1-2S typical

WEIGHTS & DIMENSIONS

• Product Dimensions (W x D x H): 19” (48.3 cm) x 8.25” (20.9 cm) x 1.65” (4.2 cm)
• Shipping Dimensions (L x W x H): 24” (61 cm) x 13” (33 cm) x 4” (10.2 cm)
• Shipping Weight: 10 lbs. (4.5 kg)