The brand new nuControl X from Nubert is nominally a preamplifier, but it is actually so much more than that. In fact, it is a control center for the contemporary hi-fi environment – naturally in high-end quality à la Nubert.
At the HIGH END 2023, the nuControl X, the latest stroke of genius from Nubert, has already made quite a few people prick up their ears. This device, unpretentiously referred to as a “preamplifier” by the clever sound-smiths, is a true universal genius that can be used as a preamplifier for analog devices, DAC and streamer and can represent the focal point and control center of the contemporary hi-fi system. In fact, the nuControl X is so versatile that its full range of functions can only be skimmed in the space of a review. But, this much in advance: this device is a high-end example of Nubert’s engineering skills and, at around 4500 euros, is still comparatively affordable. However, we don’t want to hide the fact that the nuControl X is not manufactured in Swabia, but in China – otherwise this price would hardly be sustainable.
Openness for the Win
The nuControl X aims to optimally combine traditional music playback in the home hi-fi network and popular streaming. Consequently, devices such as CD players, tape decks and, thanks to the phono MM/MC preamp, even turntables can be connected directly to the almost nine-kilogram chunk of equipment. At the same time, it can be used directly for streaming via direct access to Tidal, Qobuz, Spotify and Internet radio as soon as it has access to the Internet and its digital music offering via network cable or WLAN. Let’s take a moment here to appreciate just how much of a breeze the integration into the home network is. As soon as wired or wireless access is established, the nuControl X automatically updates itself and sets itself up. After a quarter of an hour, it is ready to play, and the really impatient can connect headphones and listen to the “greatest hits of all time” via Internet radio, for example.
If you don’t want to venture out into the digital world, you can enjoy music from your own music server via DLNA – the four-inch TFT display shows the format and resolution of the original as well as the album cover. The screen is touch-sensitive, allowing intuitive control of the complex device at the touch of a finger thanks to the well-structured menu. It doesn’t even bother me that the menu language is still English, although future firmware updates will certainly turn the nuControl X into a polyglot. The device has two headphone amplifiers, which incidentally sound nice and beefy and can either drive unbalanced headphones via the 6.3 mm jack or balanced headphones via the 4.4 mm output. There is also a USB-C port for direct connection on the front so that the nuControl X can also serve digital music to the ears independently of networks and players.
Optimized for maximum clarity
Signal processing is digital, and Nubert has gone all out when it comes to AD/DA conversion. The outstanding ES9038PRO from ESS are used. These converters work with the manufacturer’s award-winning 32-bit Hyper Stream II architecture, leaving practically no chance for jitter and are among the best in terms of dynamics and conversion linearity. The maximum resolution for PMC is 32 bit/768 kilohertz, DSD is accepted natively up to DSD512, and there is an MQA decoder on top of that – not bad, the Swabians really don’t mess around. Of course, the Nubert engineers are fully aware that a powerful DSP and top-notch converters alone do not make an audiophile summer. Consequently, the analog section has an extremely elaborate design and is strictly separated from the digital section. This is why, for example, each section has its own power supply. A look inside reveals a two-storey structure: the analogue section is located at the bottom, with the digital data center, optimized for zeros and ones, sitting above it.
As you would expect, the layout is neat as a pin, continuing the manufacturing triumph that began with the controls. The volume control via remote or the nice to the touch rotary encoder on the front is – purists breathe a sigh of relief – analog via the excellent CS3308/18 eight-channel chip from Cirrus Logic, which is digitally controlled internally for maximum precision.
Let’s move on to the connections, of which there are remarkably many: Three unbalanced RCA and two balanced XLR connections are used to connect devices such as CD/SACD players, tape recorders or tape decks that output analog line level. Turntables with MM and MC systems can also be connected, as mentioned above, and the built-in preamplifier is really impressive. We all know that it can be done even better, albeit at a much higher cost, but even so, the nuControl X’s phono pre doesn’t smack of compromise by any stretch.
As expected, there are plenty of digital connections and interfaces. S/PDIF signals are fed into the device via two coaxial or two optical inputs, an AES/EBU connection has commendably not been omitted either, so that external converters can also be connected. The nuControl X gives the user a choice when it comes to clock and jitter elimination: if the SRC, which upsamples up to a maximum of 32 bits/768 kilohertz if required, is deactivated, the converter unit synchronizes itself to the clock of the input signal. Those who have good reasons for using a reclocker such as the Mutec MC3+ USB – ideally with an additional reference clock – to completely dejitter the digital signals will typically want to bypass the nuControl X’s own clock generation.
In addition to a USB-A port for connecting storage media, there is also a USB-B interface for connecting the device to a computer. On the output side, there is also a lot on offer: there are analog RCA and XLR stereo outputs, two subwoofer outputs – the woofers can be used together – supplemented by coaxial and optical S/PDIF outputs as well as an input in addition to the obligatory LAN output. Two so-called trigger outputs – used to control a power amplifier, perhaps the nuPower A – round out the wired connection department.
Comprehensive sound control
As already mentioned, wireless connections are equally excellent: no less than three antennas are used for wireless connection via WLAN, Bluetooth or X-Connect. The latter is Nubert’s own digital wireless standard for linking speakers such as the formidable low-end specialist Nubert nuSub XW-800 slim with the “preamplifier”. Bass management is handled by the nuControl X, which is also quite competent when it comes to sound shaping. Nubert has integrated a seven-band parametric equalizer that can be used to bend the sound to your ear’s and heart’s content. Of course, there is also a loudness function and Nubert’s “sound balance”, the effect of which is shown on the display. The equalizer works in linear phase and has no sound of its own, as it serves to filter out unwanted frequencies, i.e. resonances and room modes, in order to achieve the highest possible fidelity.
This is accompanied by the option of equalizing the connected speakers via DSP. Finally, automatic calibration of the listening room is also possible with the nuControl X app. However, Android users need the optional measuring microphone, called the “XRC Android Interface”, which costs around 40 euros. Apple fans can use the iPad/iPhone microphones. The “X-Room Calibration” à la Nubert works with 32-bit resolution, i.e. with exceptionally high precision. The calibration process takes around half a minute per speaker, and the X-Room Calibration – which has been completely overhauled – even works it’s magic in my studio, too, as it brings my Geithain RL 906s noticably closer to my calibrated iLoud Precision 6 from IK Multimedia. It goes without saying that this easy to use system feels most at home in rooms that are not acoustically optimized. The app leaves it up to the user to decide whether calibration is active. So, no patronizing here.
Sound as clear as spring water
This also applies to playback. Splendid discussions can be had about whether or not upsampling makes actual sense, and I myself prefer file-accurate playback, since in my setup, a reclocker ensures jitter-free playback. Consequently, the nuControl X first receives Rachmaninoff’s Piano Concerto No. 3 via AES from the MacBook Pro/Mutec MC 3+USB team in the impressive recording by the super virtuoso Marc-André Hamelin in 24 bit/96 kilohertz – and after just two minutes it proves to be a top-notch DAC that gives my very good Mytek Stereo192-DSD a run for its money. This fine dynamic range, this selectivity with – in this respect, Nubert can always be relied upon – the highest signal fidelity is unquestionably outstanding.
So, let’s quickly connect this gem to the computer via USB and let Maestro Hamelin take to the keys again. And hear ye, the nuControl X is convincing even on its own and comes very close to my reference. Without any upsampling, mind you. Next, out goes the computer and I use the versatile preamp for wireless streaming – which is possible via WLAN and Bluetooth, the latter also bidirectionally. This works seamlessly and in the best possible quality. As I feel like it, I listen to the criminally ignored single CD by the prog-metal band Damn The Machine led by guitar crack Chris Poland from my Audiodata MS II music server, and once again it’s clear to hear: a perfect production deserves a congenial playback device. Like the nuControl X, which, all in all, is a prime example of Swabian engineering à la Nubert. Nothing less.
Accompanying Equipment
USB interface and D/A converter: Mutec MC-3+USB, Mytek Digital Stereo192-DSD DAC, Violectric V800 | Music server: Audiodata MusikServer MS II | Computer: Apple MacBook Pro 16 and MacBook Pro 13 with M1, each with Audirvana software player | Turntable: Sony PS-9X | Phono preamplifier: Violectric PPA V600 | Headphone amplifier and headphones: Violectric V200, Violectric V280, AKG K702 Studio, Beyerdynamic Aventho Wireless, Audeze MM-500 | Active speakers: Geithain RL 906, IK Multimedia iLoud Precision 6, Nubert nuPro A-200 | Cables: Vovox, AudioQuest, Klotz
Preamplifier/DAC/Streamer Nubert nuControl X
Concept: Preamplifier with DAC, streamer and numerous DSP capabilities | Analog inputs: 3 x RCA, 2 x XLR, 1 x phono (MM/MC) | Digital inputs: 2 x coaxial, 2 x optical, 1 x AES/EBU, 1 x USB A, 1 x USB B, 1 x LAN | Outputs analog: 2 x XLR, 1 x RCA (Pre), 1 x RCA (Fix), 2 x subwoofer (RCA, mono), headphones (6.3 mm and 4.4 mm) | Outputs digital: 1 x coaxial, 1 x optical, LAN loop-through tap | Network: Ethernet, WiFi, Bluetooth (aptX HD, aptX Low Latency, AAC, SBC), Nubert X-Connect for wireless high-bit networking with Nubert X speakers | Maximum resolution: 32 bit/768 kHz (PCM), Native DSD512 | Formats: all common, including MQA decoder | Streaming: AirPlay, Bluetooth, Internet radio, Roon, Spotify, Tidal, Qobuz, USB media | Special features: parametric EQ, bass/treble control, loudness, calibration via X-Room Calibration, upsampling up to 32 bit/768 kHz, control via app or touchscreen on the device | Scope of delivery: remote control, mains cable, instructions | Finishes: Aluminum, black | Dimensions (W/H/D): 43/11/39 cm | Weight: 8.6 kg | Warranty period: 2 years | Price: around € 4500
Nubert
Goethestraße 69
73525 Schwäbisch Gmünd
Phone +49 7171 87120
info@nubert.de