Streaming Client / DAC – SW1X Audio Design CDP II Review
By Thomas Schmidt at hifitest.de
Next Performance Level
In the world of high-end audio, SW1X Audio Design stands for an uncompromising return to sonic purity and analog musicality. With the CDP II, the manufacturer presents an elegant and integrated solution that unites the renowned DAC II and the VDT I/2 digital transport in a single chassis.
The designation CDP (Complete DAC Player) underscores this approach: a single-ended version of an SW1X DAC with a fully-fledged digital player/streamer. This design is ideal for anyone who wants to take full advantage of the musical and analog potential of SW1X digital technology without having to contend with the sonic challenges and often difficult tuning of separate components. Seamless integration into home networks is ensured by UPnP and DLNA compatibility, allowing the CDP II to be effortlessly controlled via touchscreen or any other network-capable interface.
Feel and Appearance
Visually, the SW1X CDP II presents itself as a classic, timeless high-end device. The casework is flawless, with a front panel available in matte black or satin silver finish.
The choice of materials and workmanship exudes understated authority, perfectly reflecting the device’s technical inner workings. The controls are reduced to the essentials: a discreet main switch, a few status LEDs, and the sturdy connection sockets on the back – nothing more is needed for a device that is designed to be operated exclusively via the network.
Technology and Construction
The integrated digital transport (VDT) is a masterpiece of engineering. All connection options are available, and balanced connections can of course also be provided upon request.
It features a discrete transistor master clock that ensures extremely precise timing. The SPDIF output signal is delivered through a tube output stage – a unique solution that enriches the signal from the outset with the warm, organic sonic character of tubes. All critical sections such as the CPU, the master clock, and the output stages are powered by discrete and completely independent linear power supplies to prevent any mutual interference. As with all SW1X products, the use of SMD components is largely avoided. Instead, only the highest-quality capacitors, resistors, transformers, and chokes are used – the same parts found in the manufacturer’s high-end DACs and amplifiers. Internal wiring is carried out exclusively with SW1X Magnum, Genesis, and Opus conductors, each selected according to the most suitable internal structure for the given application. The signal coupling capacitors are made of copper foil in oil, while the resistors are non-magnetic carbon-film types – details that reveal an uncompromising pursuit of sonic perfection.
At the heart of the DAC II section is a pure NOS (non-oversampling) R2R design that dispenses entirely with digital filtering. The converter is based on two particularly refined PCM56PK R2R DACs, carefully selected by SW1X for optimal tuning. Signal processing begins with an active I/V conversion using a special transistor with an extremely low input impedance of under 10 ohms. The following amplifier topology is a pure class-A anode-follower circuit with single-ended tubes and no negative feedback whatsoever. A 6N6P double-triode tube serves as the output stage.
The device’s power supply is exceptionally elaborate and optimized for the best possible audio reproduction. Two separate EI-core power transformers ensure a clean separation of the supplies for the digital and analog sections. Tube-rectified power supplies are used for both the master clock and the SPDIF output stage; the SPDIF stage also features choke filtering to maximize signal purity. Low-voltage sections are stabilized by discrete transistor voltage regulators.
Networking and Streaming Services
Integrating the CDP II into a home network is simple via the RJ45 gigabit Ethernet LAN port on the rear panel. The device is UPnP and DLNA compatible, enabling seamless integration into most modern network environments. Users can control the player easily through an app or a web browser on a smartphone, tablet, or computer, without dealing with complex configurations. The operating system is a Linux distribution optimized for audio playback, the widely used Volumio. This software supports a broad range of digital audio formats and offers excellent compatibility with the most popular streaming services. In this way, you can stream your music library not only locally from an attached USB drive or over the network but also access services such as AirPlay, Spotify, and TIDAL. Roon-Ready functionality (as an endpoint) is also provided, making the device an ideal partner in a Roon-based audio environment. Access to these services is intuitive via Volumio’s user interface, which allows simple management and playback of the music library.
Measurement Lab
The uncompromising NOS R2R architecture and single-ended tube circuit are deliberately designed for musicality rather than maximum measurement perfectionism. This is reflected in the test results, which depart from the common benchmark values of modern delta-sigma converters. Instead of an ultra-linear frequency response free from distortion to infinity, the SW1X CDP II presents an organic, musically tuned response. Measurements show a natural roll-off in the upper frequency range, compensating for the absence of digital filtering. Noise and jitter artifacts are reduced to a minimum thanks to the separate, meticulously built power supplies and discrete clocking. Although distortion values are higher compared to purely digital designs, they are primarily musically pleasing harmonic overtones. The tube output stage ensures decay characteristics that feel less artificial than those of semiconductor output stages.
Sound
The SW1X Audio Design CDP II delivers a sonic signature that can immediately be associated with the tube and NOS philosophy. The sound is warm, full, and organic without being indistinct or lacking in detail. On the contrary, the fine details and textures of the music are revealed with unmatched naturalness and authority. Instruments and voices appear three-dimensional and tangible in the room, with a wide and deep soundstage. The playback is free from any sharpness or hardness often found in digital systems. You can listen to music for hours without fatigue, continuously enchanted by the richness and analog flow of the performance. This player champions musicality and blends seamlessly with the recording without pushing its own technology into the foreground. Whether it’s delicate chamber music, complex jazz, or dynamic rock recordings – the CDP II masters all genres with sovereign ease. Alongside its very natural sound, it brings emotional depth to music that is rarely experienced. For those seeking an audiophile component that not only plays data but brings music to life, the CDP II is a kindred solution.
Conclusion
The SW1X Audio Design CDP II is an exceptional piece of audio engineering that deliberately turns away from purely digital measurement perfection and instead embraces the path to emotional, analog musicality. By seamlessly integrating a streamer and a tube DAC into a single chassis, it creates a harmonious sound image reminiscent of analog sources. For those who share this sonic philosophy, this is a statement device for the highest musical demands.
You can find the full review in HiFi Test 5/2025. The issue is available in our shop as an e-paper or print edition.
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Category: Streaming Client
Product: SW1X Audio Design CDP II
Price: around €12,205
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