Digital Processor Reviews

Ain't technology grand! That's what I was thinking while driving to work this morning. Sure, the rain was coming down in buckets, but there I was sitting comfortably in a warm car, listening to music while making tracks at 50mph. A long way from horse-and-buggy days.

During my reviews of digital processors in the past year or so, I've made comparisons with the Wadia 2000 Digital Decoding Computer first reviewed by Arnis Balgalvis in Vol.13 No.1. I've felt that, as good as the 2000 is, other processors—many costing less than the 2000's $8500 price tag—are now superior.

However, a visiting Wadia representative looked inside our sample and used the word "ancient" to describe its circuitry in relation to current production. In addition, I was never able to audition the 2000 with a glass fiber-optical interface, standard equipment on Wadia's transports. Similarly, the $2000 Wadia X-32 had undergone a minor circuit revision, including the inclusion of the glass optical input. Consequently, a follow-up of these two excellent processors seemed in order.

Rather a mouthful, the name of this digital decoder is derived from that of the designer, Robert Wadia Moses. The "computer" part of the title relates to the custom digital filter function generated by a set of 32-bit microprocessors: for simplicity's sake, I shall abbreviate the name to "WD1000." A more expensive version, called the '2000, sells for $6995, and carries some additional features and details. The resampling rate is increased to 64x in the '2000, with the additional optical and digital input switching and the main power supplies each contained in separate additional enclosures.

I don't remember where I was when the Berlin Wall came down, and I already don't remember what I was doing when Liz Taylor died. (I suppose I was busy not thinking about Liz Taylor.) But I do remember when USB-based computer audio became a serious medium: That was when Gordon Rankin, of Wavelength Audio, introduced asynchronous data streaming, with his proprietary Streamlength software. After that, things picked up speed.

One of the better digital front-ends I've ever heard was demonstrated for me a number of years ago at the house of an audiophile friend: a Weiss Engineering combo of Jason CD transport and Medea digital-to-analog converter. That front-end remains in my mind as one of the only digital systems I've heard that could compete with the very best that vinyl has to offer while still doing what digital does best. In other words, there were warmth and musicality, staggering dynamics, and real silent backgrounds. When, recently, I saw that the Swiss company had come out with a DAC featuring onboard volume control, a headphone amp, and a FireWire input, I knew I had to give it a listen.

When standalone digital/analog processors made an appearance a quarter-century ago, they were limited to the CD medium's 16 bits of resolution—at best. These days, almost every DAC can process at least 24 bits, and many models offer between 20 and 21 bits of real-world resolution. Modern models from Benchmark, dCS, Merging, Mola Mola, Okto, and Weiss illustrate not just the skill of the circuit designer but also that of the engineer who laid out the printed circuit board.

One of the first digital processors I encountered that offered 21 bits of resolution was the Weiss DAC202, which Erick Lichte reviewed in January 2012. Subsequent processors from this Swiss company have consistently performed well, not just on the test bench but also in the listening room.

Characteristically, the email from Kal Rubinson got straight to the point: "I have a WiiM Mini that I have played with, but I am not the right one to review this as I am not sufficiently interested in or knowledgeable about wireless streaming. It ... can handle uncompressed PCM via its DACs." "I'll review it," I replied, intrigued by a $99 D/A processor that can stream hi-rez audio via Wi-Fi and that also has an analog input so it can act as a preamplifier.