The Mastering Bundle (2 x 542 + 2 x 535 + R10 Chassis)

The Rupert Neve Portico 542 is a tape emulator in 500 series format.  As a 500-series follow-up to the Portico 5042, the 542 delivers the same thick, musical simulation of tape while drastically enhancing creative control via a number of new features. In addition to the the “true tape” circuitry – great for bringing out 3rd-order harmonics – the 542 incorporates a soft-clip circuit that tames the harshest sources and enhances 2nd-order harmonics, a variable and versatile Silk/Texture circuit for three transformer tones in one, and a wet/dry control to blend in the perfect amount of saturation.

The 542’s “True Tape” emulation circuit provides the nostalgic rounding and compression usually only achieved by the use of tape, and can offset the harshness often found in digital recordings. Unlike digital emulations, the “True Tape” drive circuit works by feeding a tiny magnetic “record head”, whichin turn is coupled to a correctly equalized, replay amplifier. As the voltage rises on the “record head”, saturation increases, and a soft clip circuit engages at higher levels to round off peak transients. The sound of the tape circuit can be further modified with selectable 15 / 30 IPS modes and a pre/post-tape blend control. In addition to the tape circuit, the 542 also has the variable Silk & Texture circuitry found in the Portico II series of modules, which allows the engineer to fine-tune the harmonic ratio and tonality on the output transformer.

Getting the Most Out of the 542
While in the olden days, tape’s non-linearity was generally looked upon as more of a curse than a “feature”, the advent of digital systems that operate in a completely linear fashion has made many appreciate the quirks of non-linear audio processing. Unlike linear designs, non-linear devices require the user to actively experiment with gain staging to find the “sweet spot” of the circuit. Although this requires a small amount of effort on part of the engineer, if used properly, the effect can add a dynamic aspect to performances that can enhance the impact of a song.

The non-linearity in the 542’s “True Tape” circuitry and Saturation control necessitate taking note of both drive and input levels. How levels are staged into the 542’s tape circuit can significantly impact tone, depending on the position of the saturation control and the drive level on the tape circuit. As saturation is increased, low frequency compensation is decreased, and at a drive level of 5 the soft clipper enters the circuit. Finding the best balance point between low frequency response, total harmonic distortion, and desired soft clipping require playing with a combination of the saturation, trim and blend controls, and may also include using dynamics processing and proper gain staging before the 542.
As a rough guide, we recommend starting with an input signal from around 2-10dBu and applying saturation, 15 / 30 IPS, Silk, and blend to taste. However, it always behooves the engineer to experiment with the balance between the pre-tape signal level and the level of the saturation control to find the best results for each source.
To get a better idea of what is happening at different saturation and “Tape Head” levels, look through the frequency response and THD by frequency response graphs in the Technical Specifications section at the end of the manual.

Also, like a real tape machine, the flux loops in the “True Tape” circuitry can pick up signals from strong nearby magnetic fields (The most likely sources are nearby power supplies, power amplifiers and computer monitors). Although we have shielded both the unit as a whole and the tape circuit to minimize stray inductance, if you have issues with hum when engaging the tape circuit, try moving the 542 to other spots away from magnetic field radiators until the hum subsides.

Adding Texture
Both Silk modes are modified and fine tuned by the “Texture” control. By manipulating the Texture control, the amount of Silk can be changed from essentially absent, to roughly four times the amount of coloration found in Silk from the original Portico Series. With Silk / Texture engaged, the distortion characteristic and harmonic content of the unit are very reminiscent of many of Rupert’s vintage class-A designs. These controls add another realm of tonal control to the 542, and should be explored creatively in conjunction with the “True Tape” for best effect.

Designed for 500 Series by Mr. Rupert Neve
Rupert Neve: “While creating functional 500-series modules is relatively simple, designing those modules to equal their non-500 series counterparts with the current, voltage and space restraints is quite challenging. In creating our own 500 Series Modules, we experimented with a number of different transformer and circuit designs to achieve the same presence and sweetness found in the Portico Series of modules. The result of these efforts is that outside of the slightly lowered headroom, our 500 series modules are nearly indistinguishable from standard Portico Series modules, and are perfectly suited for studios of the highest-caliber.”
The 542 consists of a line driving amplifier having transformer balanced inputs and outputs. The sonic quality of these amplifiers is such that by providing galvanic isolation, simple single-sided circuit topology and freedom from grounding problems, they are capable of enhancing the sonic quality of many signal sources, especially those of digital origin. The sonic “signature” is one of extreme purity and the image is consistent with that of Rupert Neve’s original designs of 35-40 years ago.

Features:

• Line Amp Specifications (Measurements with tape circuit disengaged)
• Noise: Measured at Main Output, un-weighted, 20Hz-22kHz, Input Terminated 40 Ohms.
• Unity Gain Better than -100dBu
• Frequency Response
• Measured at +10dBu, trim at unity.
• Main Output +/- 0.25dB from 5Hz to 60Khz -2dB @ 120KHz
• Maximum Output Level 23.25dBu
• Total Harmonic Distortion and Noise:
• @ 1kHz, +20dBu output level Better than 0.0025% @ 20Hz, +20dBu output level 0.07% Typical (2nd and 3rd harmonic)
• Tape FX Specifications
• Noise:
• Measured at Main Output, un-weighted, 20Hz-22kHz, Input Terminated 40 Ohms.
• Saturation @ minimum Better than -100dBu Saturation @ maximum Better than -100dBu
• Frequency Response:
• 15 IPS, Input @ -0 dBu -3dBu @ 28kHz Saturation @ minimum 0dBu @ 10Hz +5dBu Peak @ 60Hz
• Saturation @ maximum -3dBu @ 20kHz -3dBu @ 12.5Hz +2.4dBu Peak @ 60Hz
• 30 IPS, Input @ -0 dBu -3dBu @ 120kHz Saturation @ minimum -3dBu @ 10Hz +3.15dBu Peak @ 125Hz
• Saturation @ maximum -3dBu @ 100kHz -3dBu @ 12.5Hz
• +1.3dBu Peak @ 110Hz
• Total Harmonic Distortion and Noise
• Refer to sweeps on page10 15 IPS, Input @ -0 dBu 0.4% @ 3kHz to 1% @ 175Hz typical
• Saturation @ minimum Greater than 1% below 175Hz typical
• Saturation @ maximum 1% at 6kHz typical 0.3% @ 1kHz to 3% @ 50Hz typical
• 30 IPS, Input @ -0 dBu 1% at 1kHz typical
• Saturation @ minimum 0.6% @ 400Hz 5% @ 20Hz typical
• Saturation @ maximum 1.5% @ 20kHz to 0.4% @ 1kHz typical 0.4% @ 1kHz to 2 %@ 50Hz typical
• Power requirements:
• Supplied by 500 series rack with 110-125 mA @ +/- 16V DC

Rupert Neve Designs Shelford 535
The Rupert Neve Designs Shelford 535 is a single-channel 500 series compressor inspired by the same diode bridge principles found on the classic 2254. Adopting the soul sound of the legendary 2254, it is updated it for modern requirements. It offers the larger-than-life compression of its ancestor and the precision and flexibility required by current workflows. 

Originally designed for the Shelford channel, the 535 has been adapted for the 500 series format and includes a custom transformer designed by Rupert Neve and a Class A output amplifier.

The Rupert Neve Designs 535 offers quick and easy settings with a six selectable ratio ranging between 1.5:1 through 8:1 easily accessible via the rotary switch. 

The 31-step Threshold control ranges from -25dBu up to +20dBu. The Gain control offers gain compensation between -6dB and +20dB accessible through its 31-step switch.

A fixed 150Hz, 12dB/octa side-chain filter is also provided, allowing the compressor to respond less to powerful bass content avoiding unwanting triggering caused by low frequencies and keeping the compression clear.

Diode Bridge Compression
Diode Bridge compression works by using a diode’s non-linear properties to control the gain reduction.

Diode Bridge Compression was Rupert Neve’s way to create a colourful, weighty and punchy compressor before the advent of VCAs. Unlike VCA compression, which is usually thought of bringing clarity, diode bridge provides a weighty and harmonically rich tone, effortlessly bringing the source forward in the mix.

Circumventing the natural distortion levels of diodes by configuring it in a bridge format, Rupert Neve originally came up with the 2252 compressor which then evolved into the revered 2254.

The Rupert Neve Designs 535 has been meticulously designed to recreate the unique tone of the 2254 but with a much-improved noise floor. They are particularly well suited for bringing vocals, electric guitars, bass and drums at the front of the mix. 

Flexible Timing
The 535 compressor includes six selectable Timing settings that control both the attack and release times simultaneously. Each of these settings has been carefully chosen for different applications. 

• FAST: Fast Attack (750µs), Fast Release (130ms)
• MF: Medium Attack (2.25ms), Fast Release (130ms)
• MED: Medium Attack (2.25ms), Medium Release (400ms)
• MS: Medium Attack (4ms), Slow Release (725ms)
• SLOW: Slow Attack (10ms), Slow Release (1s)
• AUTO: Medium Attack (5ms), Dual-decay Release (T1 500ms, T2 1s)

Both FAST and MF settings are ideal to clamp down on transient rich material like drums or acoustic guitars. MED and MS settings offer slower reactions (slower attack and release times) for vocals, guitars while the Slow and AUTO provide smoother level control.

A FAST mode increases the speed of both attacks and release times dramatically for each setting, increasing the number of time constants from six to 12. Faster modes will also increase harmonic distortion, adding noticeable colouration to the sound. Slower modes will result in more transparent compression.

The attack and release on diode bridge compressors vary slightly depending on the ratio, threshold and incoming audio, resulting in dynamically shifting timing and harmonic content. It is an integral part of the diode bridge compressor’s sound.

A Flexible Compressor 
Rupert Neve Designs 535 Blend
The Shelford 535’s obvious colouration might prove too much on some occasions and, as a result, it includes a Blend control which lets you dial in the amount of compression to your dry, unprocessed signal. This feature might be desirable to reinject some transients lost in fast settings while retaining some of the character and punch of the compression, or simply creating a natural sound with controlled dynamics. 

Two 535 can be used together for stereo operations thanks to the included LINK button if your 500- series rack features a link control. It works by sending a control voltage via a Sidechain input so that both units are triggered equally at the incoming audio

The Rupert Neve Designs R10
The Rupert Neve Designs R10 is an ultra-rugged 500-series format delivering over 150% of the required current for optimum sonic performance.-

The Rupert Neve Designs R10 provides more than enough current in each slot to accommodate the most power-hungry module. Furthermore, it boasts LED current metering to show how much power is being used. The internal power supply is double-shielded in order to avoid significant magnetic interference between each channel.

The R10 is extremely robust thanks to its solid steel construction. It also uses an innovative sliding nuts system to accommodate modules that are built out of specs. a VCA buss link is also provided to link channels in pairs, allowing compatible compressor modules to work together.

• Provides over 150% of required current for optimum performance
• Comprehensive LED Metering shows how much power is used.
• Double Shielded Power Supply prevents significant magnetic interference
• Sliding Screw-holes accommodates out of spec modules
• VCA Link allows for module linking