Digital Processor Reviews

The Topping DM7 DAC ($599.99) is a high-resolution, eight-channel DAC that supports PCM and DSD sources but will not handle any of the common Dolby/DTS codecs. It employs the highly capable and respected ES-9038PRO DAC chip, ESS's flagship. It has just one input, and it's USB. Its eight analog outputs are fully balanced, but they are TRS (tip-ring-sleeve) phone jacks, which are more widely used in pro audio; most audiophiles will require adapters.

The June 2021 issue of Stereophile included followup reviews of two recommended components, both which deserved further investigation of what they had to offer: the dCS Bartók D/A processor and the Schiit Audio Sol turntable.

UpTone Audio's USB Regen is a powered, single-port USB 2.0 hub that takes the USB signal from your computer, regenerates (ie, reclocks) the data, provides cleaned-up 5V power from a built-in, ultra–low-noise regulator, and sends an impedance-matched signal to your DAC. The Regen is designed to sit as close to your DAC as possible; UpTone supplies a male/male USB A/B adapter—a solid, double-ended plug, which they recommend over the 6"-long male/male USB A/B cable they also provide.

I find it more than a little ironic that in 1990 the only two digital-to-analog converters to employ a new state-of-the-art DAC also use vacuum tubes. Many in the audio community consider tubes an anachronism, and find it surprising and humorous that they are still used in newly designed audio products. The fact remains, however, that these two tubed digital processors achieve the best digital playback currently available—and by a wide margin. Moreover, their respective designers' technical savvy and passion for building leading-edge products is reflected in their choice of these superlative and very expensive new DACs. Is it mere coincidence that both designers also chose vacuum tubes to realize their vision of no-compromise digital playback?

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.