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This review first appeared in the March 2014 issue of hi-end hifi magazine Audiophile Magazine of France. You can also read this review of TotalDAC
in its original French version. We publish its English translation in a syndication arrangement with the publishers. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of Audiophile Magazine or Totaldac - Ed.

Reviewer: Thierry Nkaoua
Sources: Synology DS214+, Mac Mini 2011 w. 16GB RAM and Maverick, tracks on external firewire drive, JRiver & Audirvana; Ayon S5 and Lumin network players
Analog preamps: Ayon S5, SPL Volume 2
Amp/speaker combos: Orpheus Labs 3M amp, Sonus Faber Guarneri Evolution, Van Den Hul Revolution Hybrid speaker cables in a 22m² room; Ayon Helios amp, Pascal Louvet Isis, Naturelle Audio, Live Series speaker cables in a 35m² room with PYT absorbers, Music Tools Energy bass traps, Accustica Applicata Studio DAAD diffuser
Analog interconnects: Wireworld Eclipse Platinum XLR, Transparent Premium Super XLR, Acoustic Zen Silver Reference II RCA
Digital cables: USB Totaldac, S/PDIF Viard Audio Premium HD, AES/EBU Viard Audio Premium HD
Power cords: Wireworld Silver Electra 7
Review component retails in
EU: d1-tube €6'960, d1-dual €9'900, d1-server €4'990 w.DSD option, DSD option for DACs €350€  (remove €1'100€ for DAC + d1-server), USB-filtered cable 25cm or 1m €360

The bay of Mont Saint-Michel
is famous 'round the world for its tides, embankment, quicksand and Mère Poulard’s omelet. What tourist guides don’t know? This is also the area where Vincent Brient makes his home as the designer of Totaldac products. Foreign magazines have already published laudatory articles about Totaldac including this one. Yet to my knowledge there so far has been only one review on the DAC d1-single in its home country and none on the d1-server, d1-dual or d1-tube – and this despite 40% of their annual turnover being domestic. Proprietor Vincent Brient has authored three products thus far: the d1-server network drive; the d1-tube DAC; and the balanced DAC with discrete output stage called d1-dual DAC.

A tide of innovations. One of the key terms that seem to have guided the design of each element of the DACs and drive is to abolish all jitter. That's a term for the discrepancies between data and clock signals which are one bane of digital audio. These DACs use a field-programmable gate array or FPGA like Chord, MSB, Meitner, Lumin, Playback Designs and Rockna do. These devices are integrated circuits whose logic functions can be custom written. They're used in aeronautics and telecommunications. With them a designer can implement his own proprietary algorithms.

d1-dual DAC

Vincent Brient uses his FPGA to buffer 10ms of incoming data to strip it of jitter before passing it on to the conversion stage. Compared to the S/PDIF protocol’s 80ns (a thousandth of a millionth of a second), 10 milliseconds are quite an eternity. The Totaldac reclocker built into the network drive uses the same approach but adds digital outputs reclocked as well whilst the DACs obviously output analog. As we shall see, jitter eradication remains a guiding principle also for other parts of the d1-server.

The actual converter stage is a discrete R-2R resistor ladder as championed by MSB as well. If we recall on a very elementary level that a DAC has to convert digital data into an electrical current, these data are a summation of differently weighted bits where higher weighting leads to higher voltages. Resistors are simply dividers of a given reference voltage. So bits get logically converted to a point on the ladder whose voltage corresponds to their weight. Without going into more detail, we’ll only add that an R-2R DAC uses just two resistor values – R and 2R.

For its resistor ladders Totaldac use 0.01% VAR bulk metal-foil Vishay resistors – 100 per channel for the d1-tube, 200 per channel for the fully balanced d1-dual. These electronic boards are built in France. The attendant clock is a proprietary design with another anti-jitter buffer. A full set if inputs include USB 2.0 with DoP-format DSD, coax, AES/EBU and Toslink. Non-used inputs are automatically disconnected whilst sleep mode maintains thermal readiness for key components. There’s also digital volume embedded inside the FPGA to operate at 69-bit depth.

d1-tube DAC

Totaldac offer two output stages: single-ended around two 12AU7 double triodes; and class A transistor. Regardless of model Totaldac always use an output power supply. This is a simple but effective solution to avoid electro-magnetic interface from a power transformer which can act as another source of jitter. Externalized power supplies also support lower noise for the vital analog output stage. Lastly the front panel is made of polymethylmetahcrylate or PMMA whilst a pure copper lining suppresses mechanical vibrations.

Innovation not only relates to new technologies but also identifes off-the-shelf solutions that needn’t be reverse-engineered to fulfil an assigned function to perfection. The computer section of the d1-server is a Cubox engine running on real-time (RT) Linux. There were solid reasons for using Cubox and its OS. It puts the hard discs outside the box and the shielding above the Cubox reduces EMI and associated jitter. RT Linux by design minimizes jitter with its track-decoding software and operating system. The OS and application software are embedded on a micro SD card which can be updated by computer. Audio data arrives via Ethernet LAN or USB. When connected to a hard drive, the USB port only streams data without managing any ‘audio’.


The actual software in charge of decoding audio is the MPD server which can handle up to 24/192 PCM and DSD64 in .dff and .dsf formats via the DoP convention. Once decoded the audio stream gets output to a USB port and enters the USB reclocker input 4 via a filtered USB cable whence the now reclocked data can be forwarded to an external DAC via coax or AES/EBU. The d1-server adds Airplay connectivity for secondary apps like listening to Internet radio off an iPad. Lastly these French DACs and the server come with a system remote whose looks could disappoint but which handles digital volume control for all of the DAC’s inputs and input selection, phase, grounding, display on/off, treble FIR filter on/off (always on for my auditions). Parameters for the d1-server are input, phase, grounding, native DSD or DSD-to-PCM conversion. The displays either show PCM sample rate or simply ‘DSD’.