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A shocking proof for just how important minimized OS can be is playing music with this option switched off. Anything that makes music real instantly vanishes. This is the single most powerful switch in the entire software player. All settings are performed within the user interface where help text pops up briefly under your hovering mouse pointer. For easier reading you can toggle another virtual switch to make such text appear in the central part of the window and remain open until you perform another action. Once unattended playback is active, the XXHighEnd user interface is replaced by cover-art wallpaper.
Library showing Buika’s album Mi Nina Lola selected. Input is 16/44.1 to be filtered to 32/705600. The volume setting is -48dB.
Of course this appearance can be switched off. If not, wherever cover art is present in the associated album folder, it will be resized and displayed. Displaying cover art with XXHighEnd involves no processing and thus no sonic degradation. If you opt against cover art, the XXHighEnd logo shows instead. If desired the track list can be displayed against flipped and inverted cover art and the album’s name and current track may be displayed in a larger contrasting font for easier viewing. For purists the entire display may be blacked out to prevent possible interference whenever the screen is redrawn.


NOS1 DAC selected plus the engine with Kernel Streaming mode and appropriate buffer size for the DAC
One XXHighEnd feature that's somewhat clumsy is the absence of a basic remote. Any action inside the user interface should be performed on the computer which runs the player. That's because Peter thinks and has measured that any WiFi protocol interferes too much inside the computer to degrade sound quality. His option to work with a remote is to wire up another computer running a WiFi app and from that computer take control of the player computer with Windows Remote Desktop via a WiFi-equipped handset like a tablet. Peter is working hard on a Bluetooth solution for this remote issue. He already had found a way to create a connection that handles 70MB/sec and enables the use of an iPad or Android device as long as they support Bluetooth. To make up for this inconvenience and to obtain the best sound quality, XXHighEnd includes a fantastic non-lossy volume control. Where most digital volume controls lop off least significant bits to degrade the signal, here bit integrity is guaranteed and volume control occurs in 1.5dB steps.

Whilst writing a series of article for a Dutch publication under the title The New Listening, we had our first encounter with XXHighEnd, albeit a few versions earlier than the most current. Running it from a laptop with a PS Audio PerfectWave DAC, the sound was better than any other software player we'd tested in a similar setup. Peter at that time had his own Phasure DAC built to run with his software. Our only drawback then was that his DAC still used a proprietary interface which extended the PCI bus from PC to DAC. Hence we used XXHighEnd on and off until Peter introduced the finalized Phasure NOS1 asynchronous USB DAC.


Working with almost maniacal drive not only on his software player to achieve one improvement after the next, Peter also found time to enhance his first DAC both technically and sonically. The final product is sonically utterly neutral. All sound-related setting are performed in the preceding player software, XXHighEnd or other. All filtering for 16-bit/44.1kHz material must be done in software. Higher-rez source material has no need for it because quantization noise is too high in frequency. With his NOS1 DAC Peter once again abandoned well-trodden paths. How about an H-shaped enclosure? How about a loud and clear ‘Phasure NOS1 PC D/A Converter’ punched into the top cover? How about USB bias meters powered by an external 9V battery? Under that uniquely shaped cover sit basically three separate compartments. One is for the USB interface with dedicated power supply, one for the converter boards and one for the main power supply with twin toroidal transformers.
Via the USB interface input sample rates from 22.05 up to 768kHz are presented to the DAC in 16, 24 or 32-bit word lengths. All internal processing is 32-bit. When the input data is less than 32 bits, the DAC first converts it accordingly. Following its NOS1 name, there is no oversampling or filtering. Conversion is via an octet of PCM1704U-K 24-bit chips. Output voltages are 1.5V for RCA and 2.7V for XLR. Output impedance is 33Ω. When used in combination with XXHighEnd and its bit-perfect volume control, there's no need for any preamp.


Peter explained: "This choice of 24-bit ladder chips is no coincidence. It allows for an unfiltered design which is very intentional as the entire design concept is about applying all necessary filtering prior to the DAC in player software. As far as we know this is unique. And why no filter in the DAC itself? Because now the DAC won't produce any sound by itself to where we can leave that to far more flexible software players."
Locations of the various files