SW1X Audio Design DAC III Review

SW1X Audio Design, a company based in the UK, was unfamiliar to me before this review, something I suspect will be true of many a North American audiophile. But I hope that after reading this review, you’ll seek out their products, at least to hear, if not to own. To put it quite frankly, the SW1X DAC III reviewed here is a stupendous piece of gear, not because it exceeds other DACs I’ve had in my system, but because it invited me to listen so differently from all the rest.

I don’t use the word “invited” lightly, either. I’ve heard a lot of DACs, and generally feel that I have a mental catalogue of some of the best out there. The Chord DAVE and TT2, Holo Audio May, dCs Vivaldi, old Theta Gen V’s, and a handful of other very special DACs are the kinds of contenders that generally claw their way on to my shortlist. What these DACs do for me I usually think of as bringing the music more up to my expectations of resolution, dynamic punch, transient purity — in short, bringing the music to me.

What the SW1X DAC does is very different from those other DACs, and I suspect the reason lies in its heritage. SW1X Audio Design founder and chief engineer, Dr. Slawa Roschkow (see Interview article), has taken Audio Note UK as an inspiration but not an endpoint, and when I took a peek inside the unit, I was delighted to find not only an extremely well built product, but also an exceptionally well designed one. The circuits are unusual and unabashedly so. The influence from Audio Note UK is clear, both in the tube output stage and the choice of vintage TDA1541 chip. Keen readers with an appetite for classic ‘non-interpolating’ chips, such as the Phillips TDA chips, will recognize this as the rarer and more coveted version of the TDA1547, which is also a popular chip in several modern production DACs.

The output stage is a 5687 or 6N6P dual triode, and the power supply features a choke and tube rectification, and there is zero digital filtering of any kind. This firmly places the DAC III into the ‘all-tube, no oversampling, no filtering’ category. For digital purists who want the most modern digital brickwall filters and megahertz FPGA oversampling technologies, look elsewhere. For those who may find in digital a somewhat sterile, or occasionally less engaging characteristic when compared to vinyl, read on.

In many ways the story of the SW1X, or rather my small view into it, is also the story of my vinyl journey. As a relative youngster by the terms of the hi-fi industry — a wizened 25 — I grew up largely digital. A little over a year ago I began delving into the joys of vinyl, playing with cartridges, collecting records, swapping turntables and phono stages, and generally hearing any music made before 1989 in a totally new light. One thing that particularly strikes me with vinyl is the sense of bass.

A few friends of mine are well-respected vinyl cutting engineers and, in the process of pestering them with questions, I learned that one unique characteristic of vinyl is a rather large bump at 50Hz due to the nature of cutting lathe heads and RIAA curves. In addition to this, vinyl, even in the modern era, is generally made without a digital limiter, two factors that contribute to a couple of very desirable sonic characteristics.