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Reviewer: Paul Candy
Financial Interests: click here
Digital Source: CEC TL51X transport, Audiomat Tempo 2.6 DAC, HP laptop w/ 4GB RAM & Windows XP, J. River Media Center 17, M2Tech hiFace USB-S/PDIF interface, John Kenny JKSPDIF MK3 & JKDAC32 [in for review]
Analog Source: Well-Tempered Lab Amadeus with DPS power supply, Pro-Ject Tube Box SE phono stage, Ortofon Rondo Blue MC cartridge
Amps: Audiomat Opéra Référence integrated
Speakers: Green Mountain Audio Callisto on sand-filled Skylan stands, 2 x REL Q108 Mk II subwoofers
Cables: MIT Magnum M1.3 interconnects & speaker cables, MIT Magnum digital cable, Wireworld Equinox 6 interconnects & speaker cables, Sablon Audio Panatela interconnect, Cardas Clear Serial BUSS USB [on loan]
AC Cables: MIT Magnum AC1, Wireworld Aurora 5² & Silver Electra 5², Sablon Audio Robusto & Gran Corona
Stands: Grand Prix Audio Monaco four-tier rack on APEX footers with silicon nitride bearings
Powerline conditioning: BPT Pure Power Center with Wattgate, Bybee Quantum Purifier and ERS cloth options, Blue Circle BC86 MK5, Blue Circle Sillycone Filters [in for review]
Sundry accessories: Acoustic Revive RR-77, Auric Illuminator, Audio Magic/Quantum Physics Noise Disruptors, Caig Pro Gold, Echo Busters acoustic room treatments, Isoclean fuses, HiFi Tuning Disc Demagnetizer, Nitty Gritty record cleaning machine, Soundcare Superspikes (on speaker stands), dedicated AC line with CruzeFIRST Audio Maestro outlets
Room size: 11 x 18 x 8’, long wall setup, suspended hardwood floors with large area sisal rug, walls are standard drywall over Fiberglas insulation
Review Component Retail: $1,799

DACs are experiencing a bit of a renaissance these days primarily as a result of the increasingly rapid transition from physical discs to computer-based playback. If you want optimum sound from a computer, an outboard DAC is essential. Preferably it has a USB connection and is capable of accepting up to a 24-bit/192kHz data stream. While a number of USB-to-S/PDIF converters exist for DACs without their own USB input, it's generally believed that removing the entire S/PDIF connection offers superior sonics.

Calyx Audio is a division of Korean firm Digital & Analog Co ltd. They offer a number of affordable DACs as well as class D amplifiers and speakers. Today's’ topic of discussion is their current top DAC simply named DAC 24/192. Looking not unlike a MAC Mini, the DAC 24/192’s attractive outer casing is machined from a solid block of aluminum and quite heavy for its size. The chassis sits on four small rubber-like feet. Other than a soft red/violet LED to indicate signal lock there are no buttons or controls on the front.

On the rear are pairs of balanced XLR and unbalanced RCA outputs. There are two digital inputs, USB and S/PDIF coax RCA. Calyx refers to the latter as an extra input. Obviously the DAC 24/192 is aimed at computer-based audio. That’s how I primarily used it. Also on the rear panel are two small toggle switches. One selects between inputs, the other mode of power delivery either via USB or included 5V wall wart. The Calyx features a filtered regenerative power supply to allow the DAC to draw power from a connected computer over the USB connection. The wall wart is required only for S/PDIF transfer. However I found the sound quality of the USB connection subtly improved with the wall wart and left it connected for the duration of the review.

The DAC 24/192 sports the highly regarded ESS Sabre 9018 chip which in theory can crunch a 32-bit 400kHz data stream. Since the 9018 is an 8-channel parts it’s run here in a dual-differential paralleled circuit topography i.e. two DAC channels per phase per stereo channel. In addition to providing superior linearity, S/N ratio and dynamic range in excess of 130dB, this allows Calyx to run fully balanced to its XLR outputs. For further info on the 9018, point your browser here. This chip has several impressive features so do take the time to read through the PDF. Many audiophiles attribute certain sound qualities to various converter chips and inevitably rate one brand/model over another. As with everything in audio implementation is key. The truth is, audiophiles would be better served by paying more attention to the analog output stage and power supply of a DAC. Those have a greater influence on the sound than the chip. For example I have heard all three DACs in Audiomat’s lineup. The only physical difference between them is the power supply and analog output stage yet the difference in sound quality is staggering.