Light Harmonic Da Vinci Digital-to-Analog Converter

The Vitruvian DAC

Equipment report
Digital-to-analog converters
Light Harmonic Da Vinci
Light Harmonic Da Vinci Digital-to-Analog Converter

Technical Bits
This DAC is almost annoyingly stuffed full of audio wizardry, but one thing you won’t find is any digital upsampling or oversampling. Why not? Well, it’s simple: Light Harmonic couldn’t get that kind of design to come close enough to the sound of an analog front end. Bit-perfect protection and preservation led the company to a shunt-regulated resistor-ladder architecture, but the secret sauce might well be the patent-pending three-layer buffering system that feeds the bits into the converting architecture in the most jitter-free manner possible. Aiding this are three clocks, one for 44.1kHz (and multiples) and one for 48kHz (and multiples), and also one 13MHz clock dedicated to the USB input.

With 64-bits in the volume-control architecture, the inevitable degradation that bit-tossing will introduce is reserved for far lower on “the dial”—and I put that in quotes because while adjusting volume is simple, getting to the volume control isn’t. Since the remote that comes with the Da Vinci has no volume buttons, you’re going to need a second one—for the computer. That is, the volume is modified entirely and only from the computer that’s attached to the Da Vinci; it’s your player’s software that sends the attenuation signal to the DAC (assuming your software supports volume control, but most iTunes add-ons like Audirvana do), and the DAC then handles the actual volume level.

A couple of other things: the Da Vinci does two things worth calling out. First is the least significant bit (LSB) correction. Without getting overly technical, it’s this modification to the attenuation algorithms that allows the digital volume control to achieve an unexpectedly high level of performance. I’ll say more about this in a moment, but at the risk of sidelining the review in favor of a treatise on the Promises and Pitfalls of Digital Attenuation, it’s good to know the LH team is aware of the fact that “simple” isn’t necessarily “better” in this sphere.

Speaking of digital manipulation, there’s the Duet Engine. The Web site describes this as a way to improve on the sound of “regular resolution” CD-quality audio files without upsampling or oversampling. Um, yeah. I had to ask about this. What happens is “time-aligned analog interpolation”; with parallel output modules, Light Harmonic is able to take the signals from each and perform operations on them that yield a more accurate result. Since there are two modules, this in effect doubles the sample rate. Clever. In practice, I found that the improvement was subtle but pleasing, with an unusual transparency that was surprisingly non-fatiguing.

And that’s the digital bits.

Now, if I had to categorize what it was that worries me most about DACs in general, it has nothing to do with the actual conversion. Sure, there are good and better ways to do that, and acceptable-to-bad ways of feeding those chipsets. My feeling is that these problems tend to be pretty well understood. Where most DAC designers tend to take naps is on the analog output. Here’s another place where the Da Vinci steps up.

The design is a zero-feedback architecture and if this sounds like an amplifier, then I probably won’t put you off when I say that the design is fully dual-mono, fully balanced, using JFETs with an output buffer, and there are no op-amps anywhere. The Da Vinci has both single-ended/RCA and balanced/XLR outputs, with 2.05V output on the SE outs and double that on the balanced. More specs: With better than -125dB residual noise across the audible band and -142dB of crosstalk, the whole Blackety-Blackblack and the Great Empty Nothing make sense.

Then there are three beefy R-core transformers. It’s an unusual design choice, but with separated windings it’s also one that minimizes noise. And there are 40 different regulators deployed across the architecture, from the input all the way down to the DAC chipset itself, including regulators for both the USB input and the individual clocks.

Worth Noting
Did I mention that the Da Vinci has an odd shape? That’s called understatement. Anyway, the look of this DAC is going to be polarizing. It’s not ugly by any means, but with the angles and softly glowing racing stripe that traces across the edge of the top chassis, well, it’s...eclectic. That look is a long, expensive way to go to make a Sci-Fi reference, but as I mentioned, the design choice has a purpose. The housing is actually two distinct chassis, one mounted directly on top of each other, and coupled with a rotating hinge. Yes, a hinge. The top “box,” when ready for use, will sit at a 45° angle to the lower one. I suppose this could be another reference to the where the name Da Vinci came from. The Vitruvian Man is that line drawing by Da Vinci of the longhaired naked man superimposed over himself showing two different arm and leg positions while drawn inside a square and a circle (makes sense, but I still prefer the image of Vader’s meditation chamber). Everything has a purpose, an optimal shape, is part of a well-conceived plan.

While technologically something of a marvel, the design choice means that getting to the cable inputs/outputs is a problem—I had to lift the chassis up to get at that tiny rear-mounted panel, and once exposed, it’s clear that the cables are a bit crowded in there. Tilting a 60-pound chassis around with your fingertips is going to be problematic, so do yourself a favor and give yourself some room before having at it, or better still, connect everything before getting it settled into your rack.

A note about the footers: There aren’t any attached, but there are two sets that came with my unit that you can rest the narrow bottom of the DAC on. I started out with none, simply resting the flat bottom directly on my rack’s platform, but fiddling clearly showed that there’s a positive difference with the feet instead of without. Pick one of the two supplied, or, as the Light Harmonic team suggests, find an aftermarket set that tickles your fancy.

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