Mastering Music: A Deep Dive Review Into the dCS Rossini APEX & Clock
Why the dCS Rossini APEX Is a Game Changer
PROS
- Clarity and Detail abound, Musicality Throughout
- High-end components, Ring DAC Tech
CONS
dCS Rossini APEX DAC/Network Streamer Key Features
- Latest generation dCS Digital Processing Platform brings state-of-the-art signal processing and flexibility
- dCS Ring DAC APEX, delivers enhanced sonic and technical performance
- High quality streaming from TIDAL, Qobuz, Deezer and internet radio via the dCS Mosaic Control app
- Roon Ready, AirPlay, Spotify Connect and UPnP compatible
- USB, AES, Dual AES and S/PDIF digital audio inputs.
- Accepts encrypted SACD data from dCS Transport via Dual AES inputs
- Multi-stage DXD oversampling design with optional DSD upsampling; user-selectable DSP and DSD filters.
- Auto clocking system improves ease of use and minimizes jitter.
- Multi-stage power regulation and twin mains transformers isolate analogue, digital and clock circuitry.
- Firmware-upgradeable for future functionality and performance upgrades.
- Features a full MQA™ decoder. This MQA™ implementation is unique, as it is the first opportunity to enable a DAC which, by providing exact rendering to beyond 16x (768 kHz), matches the desired temporal response with very low modulation noise.
dCS Master Clock Key Features
- Designed for maximum flexibility as output configuration can be optimized in systems with a wide variety of digital audio sources
- Dual crystal oscillators with microcontroller-enhanced temperature correction
- New dual frequency output and auto-clocking mode used in the Vivaldi and Rossini range improve ease of use and minimise jitter, particularly with computer audio sources
- Multi-stage regulation ensures sensitive clock and PLL circuitry is unaffected by digital interference
- Aerospace-grade machined aluminum chassis fitted with tuned acoustic damping panels reduces magnetic effects and vibration
Each dCS LINA system is:
Designed and hand-assembled in the UK by dCS' expert technicians and engineers
Fitted with flexible, FPGA-based firmware for a long product lifespan
Manufactured using the finest materials
Rigorously tested using state-of-the-art equipment
Created using proprietary hardware and software developed by dCS
Design
The thing about design in the audiophile world is that it becomes fairly easy to tell if something is high-end. The high-end design does not just mean a high price tag, but rather that it’s made with premium components, quality materials, and a keen understanding of how these things go together in a package that looks worthy of what you pay for it. DCS is synonymous with elegance and modernity. They’re not gaudy or industrial-looking like some audiophile equipment can be, but rather it’s an understated external chassis design that has just a brush of suave - enough to show off the fact that it takes a lot of planning and precision engineering to make a chassis this smooth and sleek. I’m a big fan of the Rossini design. Sure from afar you can mistake it for just another CNC aluminum-milled box, but it’s not until you get right up to it that you see the elegance that only dCS can accomplish. The wave pattern on the top of the front face sets it apart from the lower-tiered Bartok series.
The Difference of the APEX Upgrade
What is the APEX upgrade? The APEX upgrade is a hardware and software update that dCS introduced in 2022. It involves replacing certain critical components in the analog output stage and updating the device's firmware. This upgrade can be applied to existing dCS products, allowing owners to enhance their systems without needing to replace the entire unit.
- Hardware changes: The APEX upgrade replaces key components in the analog output stage with newer, higher-performance parts. This includes changes to the ring DAC (Digital-to-Analog Converter) circuitry, which is at the heart of dCS's digital audio processing.
- Firmware update: Along with the hardware changes, the APEX upgrade includes updated firmware that optimizes the performance of the new components and further refines the digital signal processing.
- Improved power supply: The upgrade also involves enhancements to the power supply circuitry, which can lead to better overall performance.
How does it affect performance and sound?
- Lower noise floor: The upgraded components and circuitry result in a significantly lower noise floor, which can lead to improved detail retrieval and a blacker background for the music.
- Improved dynamics: Enhanced dynamic range, with both micro and macro dynamics benefiting from the upgrade.
- Better tonal balance: The APEX upgrade provides a more natural and accurate tonal balance across the frequency spectrum.
- Increased resolution: The lower noise floor and improved circuitry allow for finer resolution of musical details and spatial cues.
- Wider soundstage: Listeners report an expanded and more precisely defined soundstage after the APEX upgrade.
- Smoother high frequencies: The upgrade results in smoother, more natural-sounding high frequencies without any loss of detail.
- Improved timing and rhythm: Enhances the sense of musical timing and rhythm, making performances feel more cohesive and engaging.
It's important to note that while these improvements are widely reported, the specific impact can vary depending on the rest of the audio system and individual listening preferences. Additionally, as with all high-end audio upgrades, the differences may be subtle to some listeners and more pronounced to others.
The APEX upgrade represents dCS's commitment to continual improvement and its desire to offer cutting-edge performance to existing customers. It allows owners of compatible dCS products to bring their systems up to the latest standards without needing to replace their entire units.
Sound
-dCS
The heart of the dCS Rossini is its proprietary Ring DAC, a testament to dCS's commitment to audio excellence. Unlike many manufacturers who rely on off-the-shelf components, dCS builds its Ring DACs entirely in-house, allowing for unparalleled control over the digital-to-analog conversion process. To appreciate the significance of this approach, it's essential to understand the fundamentals of digital audio conversion. Sound in its natural form is analog - continuous waves of air pressure that our ears interpret as music or speech. To store and manipulate audio digitally, these analog waves must be converted into digital data through a process of sampling and quantization. The quality of digital audio is primarily determined by the sample rate (how often the analog signal is measured) and bit depth (how many binary digits are used to represent each sample).
When we play back digital audio, we need to reverse this process, converting the binary data back into an analog signal that can drive our speakers or headphones. This is where a Digital-to-Analog Converter (DAC) comes into play. A DAC's primary function is to translate binary numbers into corresponding analog voltages, using a series of current sources - electronic components that generate specific amounts of analog voltage based on the digital input. Traditional DAC architectures, such as ladder DACs, face several challenges including component tolerances, zero crossing point distortion, and linearity issues, which can result in various forms of distortion potentially compromising the purity of the audio signal.
The dCS Ring DAC takes a fundamentally different approach to digital-to-analog conversion. Instead of using a fixed ladder of current sources, it employs a large number of identical current sources arranged in a ring configuration. Rather than assigning each bit to a specific current source, the Ring DAC dynamically maps the digital signal across its array of current sources. This mapping changes constantly, following a complex algorithm. By spreading the conversion across multiple current sources, the Ring DAC effectively averages out small errors in individual components. The dynamic nature of the conversion process helps to minimize issues like zero crossing distortion and improves overall linearity. Before the actual D/A conversion, the Ring DAC employs sophisticated digital signal processing to upsample the audio and shape the noise spectrum, pushing quantization errors out of the audible range.
This unique architecture offers several advantages. By averaging across multiple current sources, the Ring DAC achieves a level of precision that's difficult to match with traditional architectures. The dynamic mapping and advanced signal processing help to minimize various forms of distortion, resulting in a purer audio signal. The Ring DAC maintains its accuracy even at very low signal levels, crucial for preserving the subtle details and ambience in music. As a proprietary design, dCS can continually refine and improve the Ring DAC through both hardware and firmware updates, allowing existing products to benefit from ongoing research and development. In essence, the dCS Ring DAC represents a groundbreaking approach to digital-to-analog conversion, addressing many of the challenges inherent in traditional designs and aiming to deliver the utmost fidelity to the original audio signal, allowing listeners to experience their music with unprecedented clarity and realism.
dCS' Ring DAC seeks to correct the issues that are inherent in ladder DACs. The Ring DAC uses a network of FPGAs (field programmable gate arrays) that run proprietary dCS software that performs digital-to-analog conversion and digital filtering. A couple of things to note about the Ring DAC that make it different from a ladder DAC. A key point here is that the ladder DAC removes the link between the original signal and the physical resistor value errors associated with specific sample values.
- The Ring DAC uses current sources of equal value
- The Ring DAC does not use the same current source(s) for the same bit every time
One of the key advantages of the Ring DAC is its upgradeability via firmware updates. Featuring DXD upsampling as standard, the Ring DAC's multi-stage oversampling design offers optional DSD upsampling plus an extensive selection of DSP filters to suit individual tastes and music choices. You've got four filters with DSD content, plus six filters with PCM. I played around with PCM filtering and found the differences to be subtle, with Filter 4 offering a discernible lift in warmth and fullness to the sound.
If 1080p is the standard for high-definition video today, 4K is the premium version, 8K is still a ways off, then the Rossini APEX is easily the 16K of the future. We've talked about "realism" before here in reviews, but it's like you don't know how far something can go until you've heard the next best thing, right? That's the case with the Rossini. The Bartok and the Lina all sound end-game (as they should), but the Rossini is another game entirely. It's on another plane of existence in comparison. Details abound, and there's something about the "tone" of rings DACs that I really like the more I listen to them. It's hard to explain, but it's an extremely subtle element that makes the recordings feel a touch more organic. Perhaps it's the nature of dCS products in general, but there's a level of transparency and musicality that stands out.
I'll be honest - I'm obsessed with this setup (see the Dragon cable section for a full list). I used it in the Auris Audio Headonia Review, and I doubt I'll find a replacement for some time. Yeah, it's a pricey one, but the Rossini is the top of the totem pole so it's hard not to go all out. Abbey Road is one of those albums that I know better than the back of my own hand. Every instrument entrance, harmonies, backing parts, flubs, and more, it's one of those handful of albums I use to instantly discern the sonic abilities of a piece of gear. On Here Comes the Sun, there's a gentle and sweet element of the acoustic guitar that usually gets lost in lesser systems once the rest of the band comes in after the intro. The Rossini helps sustain this tonality of the guitar throughout the rest of the arrangement, partly due to the excellent soundstaging and imaging that it provides. There a musicality to Paul's bass playing that comes to the forefront this time around. It equally drives the tune and there's a lot of dancing around notes that the Rossini is bringing out beautifully.
The Battle from Hans Zimmer's Gladiator score has been featured numerous times on my reviews in the past. It's an endurance and dynamics test that I like to put new gear through to assess overall performance. Soft lows to bellowing highs, sub bass that easily distorts the driver - it is not a test for the faint of heart and for systems not truly up to the task. It was no issue for this setup. The Rossini Apex, combined with the Master Clock, Headonia, and the Susvara Unveiled was simply the best I have ever heard this score sound. There's few moments in this hobby where you simply have to stop and admire what is coming into your ears. This was a top 5 experience for me, and the number one spot for The Battle. I've never heard it this encompassing, impactful, full of emotion and energy. I'm one of those people that get goosebumps when listening to music (apparently a rarity according to statistics), and my skin was crawling the entire 10-plus minutes from start to finish. The shine on the brass, the warmth of the French horns, and the thundering drums is something every audiophile should experience on this earth. The Rossini + clock combo is especially capable - delivering extremely fast and dynamically stable. The HiFiMan Susvara Unveiled is a superb headphone for this setup and sound, but I tried others including the Meze Audio Elite and the Dan Clark Audio E3 with equally-exciting variations on a theme.
The sense of space and distance is something that stands out to me about the Rossini Apex. No matter the size of the ensemble, whether it be a small jazz trio, an eight-piece ska band, or a symphonic orchestra, the sound that comes from this set (the Rossini Apex and the Master Clock) is wonderfully dynamic according to the recording. The trio still fills up the room, but what helps fill in the space is provided by a sense of intimacy and proximity, being able to localize each performer and your proximity to them. Larger ensembles sound like so, but there is space provided each performer, each section, with incredible third-dimensionality. I wish I could compare this to a non-Apex Rossini to see how much is improved with dynamics, tonal balance, soundstage, and resolution, but after listening to the Rossini Apex for the duration of this review, there's really no need. Once you hear something at this level of fidelity it's going to be hard to compare. The bar is set, and the Rossini Apex and Master Clock is the real end-game deal.
by Hans Zimmer
by The Beatles
by Ottorino Respighi
Clocking: A Closer Look
-dCS
Any digital component must have a clock to understand when it's time to do something with the audio samples it receives at its input. Clocking is like a "drill sergeant" that keeps digital files aligned along their time axis. This is not just limited to the DAC chip, if one is used, but also the other digital signal components that have to keep in line with the digital-to-analog process (digital power supplies, control chips and other various pieces of the digital puzzle).
Software - dCS Mosaic
Mosaic at a Glance
Mosaic is dCS' proprietary software that allows you to browse and play music from any device running iOS or Android. Mosaic consists of three elements:
dCS Mosaic is the name for the audio streaming and networked control functionality of dCS products.
dCS Mosaic Control is the name of the iOS and Android software application for music management and product control.
dCS Mosaic Processor is the physical hardware component and associated software that is installed in the dCS product to provide streaming functionality.
dCS Mosaic is a bespoke collection of hardware and software modules that allow you to access your digital music. When it comes to controlling your music library, a well-executed app can make the experience that much more seamless and pleasurable. The dCS Mosaic app for iOS and Android offers an intuitive way to browse and access music from multiple sources and audio libraries. Mosaic brings together audio from multiple sources into a single, unified interface, making multi-source playback simple. You can use the app to browse media from various streaming services and to manage settings and configuration options for your dCS products. Mosaic is compatible with:
- UPnP
- USB
- Internet Radio
- TIDAL, Qobuz, Deezer
- Spotify via the Spotify Connect app
- Podcasts via Airable
Since the Rossini Apex is Roon Ready, you have the option of using Roon as your media management platform. If you have a Roon account, install Roon Core on your NAS drive or on a networked computer. You can then use Roon remote to control playback on your Rossini Apex. Why might you opt to run Roon instead of Mosaic? It comes down to user experience – and your willingness to pay a monthly subscription fee.
Roon was created for the music streaming enthusiast who wants a highly curated experience. It's a virtual playground for music discovery, where you can spend as much time researching as you do listening. Now, Roon offers the basics like album info, artist info, and track info. But Roon takes it many steps further with things like extensive artist bios, artist suggestions, and lots of visual pizzazz. The home screen in Roon is a personalized experience with personal stats, recent activity, suggestions, playlists, and more. One thing to note is that you can't access internet radio through Roon like you can with Mosaic.
Mosaic offers a more streamlined, minimalist user experience. A great thing about Mosaic is that it's a custom code developed by dCS that can be upgraded and enhanced over time. Neither Roon nor Mosaic is the better choice; it all comes down to user preference. And it's great to have the option to use either.
Be sure to check out our Ultimate Guide to Setting Up Your Roon Ready Device for more info on setting up your Rossini Apex with Roon.
Dragon Cables
Testing Setup:
- dCS Rossini APEX DAC/Music Streamer (with Silver Dragon Network Cable, Silver Dragon Digital Coax Cable, Black Dragon Power Cable)
- dCS Rossini Master Clock (with Silver Dragon Digital Coax Cable, Black Dragon Power Cable)
- Auris Audio Headonia 300B Tube Headphone Amplifier (with Silver Dragon Interconnect, Black Dragon Power Cable)
- HiFiMan Susvara Unveiled Open-Back Planar-Magnetic Headphone (with Black Dragon Premium Headphone Cable for HiFiMan)
Silver Dragon Sound Signature: The Silver Dragon is Moon Audio's original cable. Silver strands clarify instrument separation, increase the soundstage, and find previously lost high and mid-frequency sounds. Transients appear more cohesive and the bass tighter for a more controlled sound. The detail and clarity of the Silver Dragon make it a perfect match for classical music and other genres with many nuanced instruments.
Black Dragon Sound Signature: The Black Dragon is warm and smooth with a musical presentation. Copper strands enhance the body, shape, and immediacy of the music. The detail and expansiveness of the Black Dragon make it a flexible fit where a broad range of musical genres are played. It can also improve bass frequencies on bass-light audio components.
Our HiFi Audio Dragon Cables bring out more of what you love in your music and audio gear. If you love your headphones but wish they had a bit more top-end sparkle - a Silver Dragon Headphone Cable would be a great option. If your USB cables keep dying - as many stock cables do - then check out our quality USB Audio Cables. We say time and time again that materials matter, and our audio cables and custom geometries actually help to bring out those desired properties in your gear and music. We make tons of custom options for our customers so that you can get the right HiFi Audio cable for your exact needs. If you have any questions feel free to Contact Us and we'll be more than happy to help.
Verdict
Featured Products
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What's in the Box
-Black Fabric Drawstring Bag
-Manual
-Quick Menu Guide
-dCS Mosaic Control Quick Reference Guide
-AC Power Cable
-Black Fabric Drawstring Bag
-Manual
-AC Power Cable
Frequently Asked Questions
What is the dCS Rossini APEX player?
The Rossini APEX is a high-end digital audio component that combines a state-of-the-art digital-to-analog converter (DAC) with network streaming capabilities. It's designed by Data Conversion Systems (dCS), a British company known for its cutting-edge digital audio technologies. The APEX designation refers to their latest DAC architecture, which represents the pinnacle of dCS's engineering efforts.
How does the APEX version differ from the original Rossini?
The APEX version incorporates significant improvements to the DAC hardware. This includes enhanced analog output stages and refined DAC Ring technology. The result is lower noise levels, improved linearity, and better overall sound quality. Users often report increased clarity, a more defined soundstage, and improved low-level detail retrieval compared to the original Rossini.
What audio formats does the Rossini APEX support?
The Rossini APEX is extremely versatile in terms of format support. It can handle PCM audio up to 24-bit/384kHz, including high-resolution formats like DXD (352.8kHz and 384kHz). It also supports DSD (Direct Stream Digital) up to DSD128 (5.6MHz). This wide-ranging support ensures compatibility with virtually all high-resolution audio content available today.
Can the Rossini stream music from online services?
The Rossini APEX is designed as a network-connected device. It can stream music from popular services like Tidal, Qobuz, and Spotify Connect. It also supports UPnP/DLNA protocols, allowing it to stream music from network-attached storage (NAS) devices or computers on the same network. The dCS Mosaic platform provides a user-friendly interface for controlling these streaming functions.
Does the Rossini have MQA support?
Yes, the Rossini APEX includes MQA decoding capabilities. MQA (Master Quality Authenticated) is a high-resolution audio format that's becoming increasingly popular. The Rossini APEX includes full MQA decoding capabilities, allowing it to unfold MQA files to their full resolution. This is particularly useful for users of Tidal's HiFi tier, which offers a large library of MQA-encoded tracks.
What connectivity options does the Rossini offer?
The Rossini APEX offers a comprehensive set of digital inputs: USB, AES/EBU (x2), S/PDIF coaxial (x2), S/PDIF optical (x1), and Ethernet for network connectivity. For outputs, it provides balanced XLR and unbalanced RCA analog outputs. This wide range of connections ensures compatibility with a variety of audio systems and sources.
How does the Rossini compare to other high-end DACs?
The Rossini APEX is often considered one of the best DACs available, competing with top-tier products from brands like MSB, Chord, and EMM Labs. It's praised for its neutral, detailed sound, expansive soundstage, and ability to render complex musical passages with ease. Its network streaming capabilities also give it an edge over DAC-only devices in terms of versatility.
Is there a CD transport option?
While the Rossini APEX doesn't include a built-in CD drive, dCS offers a separate Rossini CD Transport. This is a dedicated CD player designed to pair perfectly with the Rossini APEX, using dCS's proprietary Clocking architecture for optimal performance. The transport connects to the APEX via dual AES/EBU connections.
Can existing Rossini owners upgrade to APEX?
Yes, dCS offers an upgrade path for owners of the original Rossini to the APEX version. Contact Us for more info.
Does the Rossini APEX Player need a Master Clock?
With an auto-clocking system integrated into the Rossini APEX Player to reclock timing errors and reduce jitter, it can operate without an external clock but we always recommend adding a Master Clock to high-end audio products. A high-quality dedicated Master Clock like the Rossini APEX Master Clock will ensure you receive the highest-quality sound every time you listen.
Specifications
Type: Upsampling Network DAC.
Color: Silver or Black
Dimensions: 444mm / 17.5” x 435mm / 17.2” x 125mm / 5.0“. Allow extra depth for cable connectors
Weight: 15.6kg/34.3lbs
Converter Type: dCS proprietary Ring DACTM topology. Operates at 6MHz (Map 1 or 3) or 3MHz (Map 2)
Digital Inputs: Ethernet network port on RJ45 connector, accepts 24-bit 44.1 – 384kS/s PCM, DSD/64 & DSD128 in DFF/DSF format; USB 2.0 interface on B-type connector, accepts 24-bit 44.1 – 384kS/s PCM, DSD/64 & DSD128 in DoP format; USB On-The-Go interface on A-type connector, accepts 24-bit 44.1 – 384kS/s PCM, DSD/64 & DSD128 in DFF/DSF format; 2 x AES/EBU inputs on 3-pin female XLR connectors, accepts 24-bit 44.1 – 192kS/s PCM, DSD/64 & DSD/128 in DoP format; 1x Dual AES pair, accepts 24-bit 88.2 – 384kS/s PCM, DSD/64 & DSD/128 in DoP format; 1 x SPDIF on RCA Phono connector, accepts 24-bit 44.1 – 192kS/s PCM & DSD/64 in DoP format; 1x SPDIF on BNC connector, accepts 24-bit 44.1 – 192kS/s PCM & DSD/64 in DoP format; 1 x SPDIF optical on TOSLINK connector, accepts 24-bit 44.1 – 96kS/s PCM
Analog Inputs: 1 x pair balanced outputs on 2 x XLR connectors. Output levels: 0.2V, 0.6V, 2V, 6V rms for a full-scale input, set in the menu. Output impedance: 3Ω. Maximum load: 600Ω (10k-100kΩ is recommended); 1 x pair unbalanced outputs on 2 x RCA connectors. Output levels: 0.2V, 0.6V, 2V, 6V rms for a full-scale input, set in the menu. Output impedance: 52Ω. Maximum load: 600Ω (10k-100kΩ is recommended)
Wordclock I/O: 2 x Word Clock Inputs on 2 x BNC connectors, accept standard Word Clock at 44.1, 48, 88.2, 96, 176.4, or 192kHz. The data rate can be the same as the clock rate or an exact multiple of the clock rate. Sensitive to TTL levels. 1 x Word Clock Output on 1 x BNC connector. With Sync Mode set to Master, a TTL-compatible Word Clock is output
MQA: Full decoding and rendering of MQA data from the Network and USB2 inputs. Final rendering of unfolded MQA data only from the other inputs
Residual Noise: 24-bit data: Better than –113dB0, 20Hz - 20kHz unweighted. (6V output setting)
L R Crosstalk: Better than -115dB0, 20Hz – 20kHz
Spurious Responses: Better than -105dB0, 20Hz – 20kH
Filters: PCM mode: up to 6 filters give different trade-offs between the Nyquist image rejection and the phase response. DSD mode: 4 filters progressively reduce the out-of-audio band noise level, plus Filter 5 which has an improved transient response
Conversions: User-selectable PCM upsampling to DXD, DSD or DSDx2
Software Updates: Loaded from CD-R via PCM digital inputs or PC via USB input. Download and update functionality available via the dCS Mosaic App
Local Control: dCS Mosaic App for Unit Configuration and Music Playback. RS232 interface (controlled by a 3rd party automation system). IR remote control – dCS Universal Remote available as an optional extra
Power Supply: Factory set to either 100, 115/120, 220 or 230/240V AC, 50-60Hz
Power Consumption: 23 Watts typical / 28 Watts maximum
Operating Systems: USB Audio Class 1 & 2 fully supported by Windows 10/11 & OSX 10.10 or later
Type: Class 1 Master Clock
Clock Frequencies: 44.1kHz or 48kHz
Color: Silver or Black
Dimensions: 444mm/17.5” x 435mm/17.2” x 64mm/2.6”. Allow extra depth for cable connectors
Weight: 8.3kg/18.3lbs
Clock Accuracy: Better than +/-1ppm when shipped, over an ambient temperature range of 10°C to 30°C. Typically +/-0.1ppm when shipped and stabilised
Wordclock Outputs: 3 independently buffered outputs on 75Ω BNC Connectors. Output 1: fixed at 44.1kHz. Output 2: fixed at 48kHz. Output 3: 44.1kHz, switchable to 48kHz via RS232
Startup Time: Typically 1 minute to rated accuracy
Local Control: RS232 (limited to Power and Clock 3 output frequency)
Power Supply: Factory set to either 100, 115/120, 220 or 230/240V AC, 50-60Hz
Power Consumption: 3 Watts typical / 4 Watts maximum