Digital Processor Reviews

Some high-end audio companies develop reputations for having a particular "sound." This reputation develops when every product the company makes has a similar sonic flavor. These products appeal to certain customers who like the company's sound, and who therefore tend to stay with that company's products year after year. Unfortunately, such an approach can limit a manufacturer's appeal to a broader audience.

In hindsight, it was inevitable that two sophisticated digital audio technologies—software-based digital filters and Bitstream D/A converters—were destined to be married in one product. The software-based D/A converters offered by Krell, Wadia, and Theta all used multi-bit ladder DACs, and Bitstream-based units have previously relied on off-the-shelf digital filters.

As the sides of the slim-line Timbre Technology TT-1 DAC are radiused rather than flat, it's elegant compared to its typical boxy competition. While the TT-1's handsome shape stands out more than your average audiophile device, its curved sides help create a stronger, less resonant shape than the usual box, and serve as just one of the many elements contributing to a high degree of mechanical integrity and damping.

Stereophile's March 2023 issue includes two follow-up reviews of high-performance digital playback products: the Benchmark DAC3 B D/A processor; and the Rotel Diamond Series DT-6000 DAC Transport (a CD player with digital inputs).

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?

For the audiophile modernist, a DAC with volume control is the straightest path between the music server or network stream and your amp and speakers. If you've fully embraced networked audio, there's no need for fussy preamps with their analog inputs, analog volume controls, and [gasp!] phono stages. Find a digital source, a DAC with volume, and go.