MASTER BUS TRANSFORMER
OVERVIEW / MEDIA / FEATURES / REVIEWS / SPECS & RESOURCES
Transform your tone.
For over six decades, audio transformers have been the bedrock of Mr. Rupert Neve’s audio circuit design philosophy – and Rupert Neve Designs’ bespoke transformers are an integral part of virtually every RND product.
Packed with these transformers, the MBT provides an incredible array of flavorful options designed to sweeten, enhance, drive, widen, and utterly transform source material, making it the ultimate tool for musical coloration.
“Once you’ve inserted the MBT on your master bus, everything that follows requires only your ears, intuition and creativity.”
Create Tonal Magic with the Shelf EQ
With 3 octave ranges, gentle slopes and minimal phase shifts, the all-new 2-band Shelf EQ section was created with an emphasis on simplicity and elegance. This smooth & musical EQ is excellent at providing just the right amount of tonal enhancement – especially when it is interacting with the other sections of the MBT.
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Each band has +/- 9dB of gain control, with the LF EQ corner frequency variable from 30Hz to 240Hz and the HF EQ corner frequency variable from 3kHz to 24kHz.
The LF band is excellent at either taming or accentuating low-end to give source material an exacting amount of weight and power.
The HF band provides a wide range of corner frequencies to choose from, allowing adjustments to be made from the upper midrange all the way up to the very top end, giving tracks extra shine and clarity.
One exciting aspect of using the MBT is discovering how the different sections can interact with each other. Sometimes the EQ can be dialed in first, other times it can be left alone until the other sections are dialed in. One thing is certain: the MBT encourages experimentation at every turn.
Breathe In New Life with the Color Comp
With an all-new optical compressor design, the Color Comp excels at accentuating the non-linear distortion and “colorful” characteristics of the Opto cell to bring source material a new sense of life and depth.
The Color Comp includes two selectable ratios, a sweepable high pass side-chain filter, variable threshold and release, 20dB of Class-A makeup gain, and a Blend control for parallel processing.
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The compressor ratio can be set to a 2:1 ratio (LO) for subtle & smooth compression or 5:1 (HI) for much more dramatic behavior.
The variable high pass side-chain filter removes the low frequencies from the compressor side chain circuit, allowing low-end information to pass through the compressor untouched while the compressor focuses on the rest of the signal. With a sweepable range from 20Hz all the way up to 350Hz, this is a highly flexible tonal shaping control providing the ability to leave the low end intact while taming or squashing the rest of the source material as needed.
The Color Comp also contains a Blend control, making it easy to use the compression circuit in parallel with the uncompressed source material. This can be especially useful when wanting to dial back the harmonic content, dynamic range reduction, and transient squashing from more extreme compressor settings.
The threshold is variable from 0dBu to +24dBu, with a gain reduction LED illuminating when the signal passes the threshold. However, the Color Comp also introduces audible non-linear harmonic content even with just a touch of gain reduction – as such, we highly recommend listening to the Color Comp engaged even when no gain reduction is visible, in order to discern the amount of tonality that it introduces. The pleasing nature of this harmonic content will become even more apparent as the compressor settings become more extreme.
The release is variable from 100mS to 1.5S. By dialing in higher ratios and faster releases it is possible to get the color comp to actively “pump” with the attacks, whereas with slower release times it will operate in a much smoother manner.
Lastly, the Color Comp has 20dB of Class-A makeup gain. This is not only useful for level-matching the before and after compression signals, but also for driving the interstage transformers found in the Super Silk section for even greater harmonic enhancements.
“The opto compressor sneaks up on you and then sweeps you off your feet....punchy when used moderately, stealth ferocity if you push it to the brink.”
BJÖRK, SUFJAN STEVENS, DEERHUNTER, BEACH HOUSE
Find New Dimension with Width
The Width section is designed to increase the perceived stereo spread without losing low-end focus.
While inspired by the Stereo Field Editor (SFE) “WIDTH” controls found on our award-winning Master Buss Processor, the MBT’s Width section has several key differences:
The Width control on the MBT is additive only, with a greater range for more extreme operation.
There is a variable high-pass filter (50Hz to 800Hz) to adjust the Width content, so that low frequencies remain more centered in the mix as the mids and highs are spread out to create more space.
Additionally, there is subtle high frequency tapering of the Width content to avoid overemphasizing harsher HF tones.
INTRODUCING
Super Silk
Introduced nearly twenty years ago, the Silk circuit has long been a favorite for Rupert Neve Designs users. First available as a simple on/off switch, then with selectable Red and Blue modes and the variable Texture control, Silk exists to enhance and control even and odd order harmonic content in any source material.
Super Silk is the latest advancement to this beloved technology: with independent Red, Blue, Harmonics and Zener Drive controls, plus the ability to adjust gain into (and out of) the circuit, harmonic manipulation is taken to a whole new level with the MBT.
RED accentuates harmonics in the upper mid and high frequencies, adding sparkle and sheen.
BLUE accentuates harmonics in the low & low mid frequencies, creating more depth and weight.
HARMONICS increases the overall musical harmonic content, and interacts with both Silk BLUE and RED.
ZENER DRIVE introduces a diode-based soft-clip circuit for a more aggressive tonality as the MBT approaches clipping.
SILK IN engages or bypasses the entire SUPER SILK section – and is now finally “Silk Purple”, one of our most-requested features.
“This is a near-instant love affair. I’ve fallen for it even quicker than any other RND products.”
MATT MAESON, SARA BAREILLES, VANCE JOY, METRIC
INPUT LEVEL: LED indication that illuminates GREEN when the input signal reaches -20dBu and illuminates RED to show when the input signal reaches +23dBu. This indication is post input trim control.
INPUT TRIM: 31-detent potentiometer that controls the input level within a range of +/- 12dB.
HPF FREQ: 31-detent potentiometer that controls the HPF frequency within a range of 15Hz to 100Hz.
HPF IN: Push-button switch that illuminates GREEN when the 6dB/octave HPF is engaged.
LF: 31-detent potentiometer that controls the Low Frequency Shelf gain within a range of +/- 9dB.
LF FREQ: 31-detent potentiometer that controls the Low Frequency Shelf corner frequency within a range of 30Hz to 240Hz.
HF: 31-detent potentiometer that controls the High Frequency Shelf gain within a range of +/- 9dB.
HF FREQ: 31-detent potentiometer that controls the High Frequency Shelf corner frequency within a range of 3kHz to 24kHz.
EQ IN: Push-button switch that illuminates GREEN when the equalizer section is engaged.
THRESHOLD: 31-detent potentiometer that controls the compressor threshold within a range of +24dBu to 0dBu.
S/C HPF: 31-detent potentiometer that controls the corner frequency of the side-chain high-pass filter within a range of 20Hz to 350Hz.
COMP IN: Push-button switch that illuminates GREEN when the compressor section is engaged.
GAIN REDUCTION: LED that illuminates GREEN when gain reduction is occuring. The LED indicates compression for left and right channels.
RELEASE: 31-detent potentiometer that controls the Release time of the compressor within a range of 100mS to 1.5S.
RATIO: Opaque push-button switch that toggles between a LO (OUT) 2:1 ratio and a HI (IN) 5:1 compressor ratio curve.
BLEND: 31-detent potentiometer that controls the amount of dry (0%) vs. wet (100%) compressed signal in the audio path.
GAIN: 31-detent potentiometer that controls the amount of compressor make-up gain within a range of 0dB to +20dB.
WIDTH IN: Push-button switch that illuminates GREEN when the WIDTH section is engaged.
WIDTH HPF: 31-detent potentiometer that controls the corner frequency of the width processing HPF within a range of 50Hz to 800Hz.
WIDTH: 31-detent potentiometer that controls the amount of Width stereo field processing within a range of MIN to MAX.
SILK IN: Push-button switch that illuminates PURPLE when the SUPER SILK section is engaged.
BLUE: 31-detent potentiometer that controls the amount of low frequency SILK pre-emphasis.
DRIVE: LED that illuminates RED when the signal level reaches the optimal range for transformer harmonics. The LED indicates drive level for left and right channels.
RED: 31-detent potentiometer that controls the amount of high frequency SILK pre-emphasis.
HARMONICS: 31-detent potentiometer that controls the amount of transformer harmonics added to the audio path.
ZENER DRIVE: Push-button switch that illuminates AMBER when the soft clip circuitry is engaged.
BYPASS ALL: Push-button switch that illuminates RED when the master bypass is engaged. This master bypass is a true hard- wire bypass that ensures the MBT will pass audio in the event that power is lost.
OUTPUT TRIM: 31-detent potentiometer that controls the amount of output trim within a range of +/- 12dB.
OUTPUT METERS: Stereo 16-segment LED meters that indicate output level in dBu.
POWER: LED that illuminates GREEN when POWER is ON.
POWER: IEC standard 3 pin grounded switched AC power inlet with an input range of 100-240 VAC. 70 Watts maximum AC power consumption.
GND LIFT: Slide switch that lifts XLR Output Pin 1 from chassis ground to minimize ground loops.
OUTPUT: Balanced XLR outputs with custom Rupert Neve Designs transformers capable of handling up to +25.5 dBu at 1kHz.
INPUT: Balanced XLR combo jack inputs capable of handling up to +25.5 dBu at 1kHz.
Equally at home on a full mix, groups, stems or individual sources, the MBT pairs legendary tone with an immensely flexible set of controls to shape your sound.
REVIEWS
"Rupert Neve Designs’ Master Bus Transformer is an extremely impressive device that delivers exactly what its designers intended it should...once you’ve inserted the MBT on your master bus, everything that follows requires only your ears, intuition and creativity."
"I’d urge anyone who has both the need for bus or mastering colour and the budget available to audition an MBT at the earliest opportunity. I’ll be very sorry to see this one leave!"
Bob Thomas // Sound On Sound
"The dual Silk modes and the ability to blend between them, with or without drive is pretty awesome and it will be what most people will be totally allured by at first. But then comes the opto compressor…it sneaks up on you and then sweeps you off your feet. You don’t expect to be surprised by it until you use it with various programs and see how far it can go. Punchy when used moderately, stealth ferocity if you push it to the brink, not to mention the signal interplay with the harmonic/drive section is a joy to play with.”
“EQ, imaging and gain staging options. So many great features usually sourced from various units but all in one box. I think for the hybrid or mostly ITB engineers looking for that one silver bullet unit that is all tone and screams analog with a capital A, the MBT is brilliant."
Heba Kadry, Mastering Engineer
Björk, Sufjan Stevens, Beach House, Slowdive, Ryuichi Sakamoto
“When I come out of the DAW, it’s to impart a color, to impart a character…one of the great things about this box is that it has a lot of high quality, high-impact sonic signatures that you can impart on a recording, but without a thousand knobs.”
Dale Becker, Mastering Engineer
SZA, Doja Cat, Khalid, Snoh Aalegra, Lil Durk, Kim Petras
“It's one of those things that once I've heard it I don't want to work without it. There aren't many pieces of gear like that…it’s just been eye-opening how good this thing is. Smooth EQ, color compression, the stereo widener’s killer, and the transformers with the Red and Blue – just really, really nice stuff. I can’t say enough good things about it.”
Kevin Madigan, FOH Engineer
Carlos Santana
"The MBT is a special box. The Super Silk circuit with Zener drive will be revolutionary for many engineers. My initial thoughts on the color comp is it seems very usable and unique, and the blend knob is invaluable. I'm using it on my stereo bus at the moment, but the potential for parallel group processing is obvious and exciting. "
Brett Orrison, Mixing / FOH Engineer
Jack White, Widespread Panic
“The MBT just adds the right touch of transformer magic in today’s digital world! Apart from the usual 2-bus duties it was amazing as a drum bus insert, and even as an insert for an all vocals group. It has all the elements needed to tweak and enhance anything.”
“La combinación de todas las secciones del MBT hacen que sea un equipo muy versátil. La sección de ‘Width’ y ‘Súper Silk’ son de mis favoritos! Y bueno los transformadores que tiene son increíbles, le agregan un peso súper musical y tridimensional al sonido cuando son usados en combinación con el mundo digital, es el duo perfecto.”
Lewis Pickett, Mix Engineer / Producer
Marc Anthony, Carlos Vives, Alejandro Sanz
“In addition to the saturation, there’s something about the Blue Silk, the way that it saturates the low end and the low band EQ with the high pass filter, that gives me the best low end I’ve ever had in my career, and I don’t say that lightly – like, there’s some magic happening there…the way you can shape and mold the low end is absolutely incredible.”
Colt Capperrune
“I think that the Rupert Neve MBT is a game changer in modern productions. I do a lot of dance music, pop, hip-hop, and rock. The Master Bus Transformer completely replaces all the plugins on my mix bus, and it is extremely easy to use. The EQ on the input stage is perfect, Super Silk replaces all my tape and saturation plugins…Super Silk is a wow factor when mixing, it shapes the music in a crazy musical way. I had to leave the room and scream because it just all made sense.”
“I love how easy the unit is to use – it’s really fun because the tone shaping from the box is so accurate, it’s the only piece I need when printing a mix. I always like the concept of less is more and this piece blows me away! Less is more, and this piece makes mixing easy and fun. I’ve had a lot of plugin chains over the years…any plugin I’ve tried pales in comparison to Super Silk.I have been in love since I opened the box.”
Perfetto, Producer / DJ
“It’s the punk rock younger brother to the MBP, and a perfect studio utensil for squeezing every last drop of juice out of tracks, stems, and mixes.”
Danny Reisch, Mixer / Producer
Other Lives, White Denim
“I’m constantly proclaiming that such a piece of gear is the last piece of analog gear I will ever buy. But you guys keep ruining that for me, because now I’m going to have to keep this…this is a near-instant love affair. I've fallen for it even quicker than any other RND products.”
John O’Mahony, Mix Engineer
Matt Maeson, Sara Bareilles, Vance Joy, Metric
“Since I had already incorporated the MBP and MBC to my Main L&R mix, I decided to use the MBT on my stereo guitar bus. With having no real amps on stage, the MBT really woke up my guitar sound. It added width and grit that I was missing from the modelers and made them feel more real. You can't replace the sound of transformers.”
Kyle Gerhart, FOH Engineer
Scott Stapp, Fuel
SPECIFICATIONS & DOWNLOADS
Note: All measurements typical; All measurements recorded using 25ft. XLR output cables with Balanced ZSOURCE = 40 ohm
Input Impedance: 10 kilohm
No Features Engaged
Noise (22 Hz - 22kHz): Better than -95 dBu
THD+N (0 dBu @ 1kHz): Better than 0.004%
THD+N (+20 dBu @ 1 kHz): Better than 0.002%
Maximum Input Level: +25.5 dBu
Crosstalk @ 1 kHz: Better than -95 dB
Frequency Response:
<5 Hz - 30 kHz: +/- 0.1 dB
<5 Hz - 60 kHz: +/- 0.25 dB
<5 Hz - 180 kHz: -3 dB
HPF Engaged
Noise (22 Hz - 22 kHz): Better than -95 dBu
THD+N (+20 dBu @ 1 kHz): Better than 0.002%
Equalizer Engaged
Noise (22 Hz - 22 kHz): Better than -93dBu
THD+N (+20 dBu @ 1 kHz): Better than 0.002%
Compressor Engaged
Noise (22 Hz - 22 kHz): Better than -92dBu
THD+N (+20 dBu @ 1 kHz): Better than 0.002%
Width Engaged
Noise (22 Hz - 22 kHz): Better than -88dBu
THD+N (+20 dBu @ 1 kHz): Better than 0.002%
SILK Engaged
Noise (22 Hz - 22 kHz): Better than -95dBu
THD+N (+20 dBu @ 1 kHz): Better than 0.003%
WEIGHTS & DIMENSIONS
Product Dimensions (W x D x H): 19” (48.3 cm) x 10.125” (25.7 cm) x 3.5” (8.9 cm)
Shipping Dimensions (L x W x H): 22” (55.9 cm) x 18” (45.7 cm) x 8.7” (22.1 cm)
Shipping Weight: 17 lbs. (7.7 kg)
FREQUENTLY ASKED QUESTIONS
Absolutely! We encourage you to try out the MBT on various individual sources to see how it can bring life to snare drums, acoustic guitars, pianos, vocals, strings, and anything else you can think of. Note: please remember to convert any mono sources to a stereo STEM before feeding the MBT.
No; the input stage is based on our highest-quality line amplifier circuit, and was intentionally designed to be clean so it can safely drive the other more colorful sections of the MBT. However, our custom transformers ARE found in the interstage Super Silk circuit, and on the unit’s output.
The attack time is fixed at 20mS. This should allow most transients to sneak through without being overly compressed.
The LO ratio setting is 2:1 and the HI ratio setting is 5:1; the former will sound a bit gentler, whereas the latter will be significantly more aggressive.
Absolutely not. Every section of the MBT is different than the MBP – even the updated Width section. Tonally, they are also quite different and complementing each other when used in tandem. In fact, with both the MBP and the MBT you may have all your bases covered to professionally finish any track.
Not exactly: With the MBT we decided to include an additional dedicated pair of our custom transformers solely for the SUPER SILK section. This allows you to get much closer to core saturation and generate more harmonic content than ever before.
SUPER SILK also offers far more precision and control, since you can now drive into the circuit via gain stages earlier in the unit (INPUT Trim, EQUALIZER & COLOR COMP Gain), and then compensate for any increased level using the master Trim control in the OUTPUT section.
The following may also be of interest:
Master Buss Processor
5254 Dual Diode Bridge Compressor
Master Bus Converter