Digital Processor Reviews

What I categorize as mainstream, dealer-based, fancy-pants streamers and big-speakers audio is actually only the gold-plated tip of a gigantic asteroid-like monolith that extends (underground) from New York to Hong Kong, from the Arctic Circle to Antarctica.

For a couple of years, I have been following Prague-based Okto Research. At first, Pavel Krasensky, the founder and hardware developer, offered audio design ideas and DIY modules that I found tantalizing. For example, there was a dandy-looking ESS 9038Pro Sabre–based output module and some appealing power supply modules—but to use those, the buyer had to manage inputs and integration on their own.

Then, finally, last year, Krasensky released the dac8 PRO, an 8-channel D/A processor with USB input and output, 8 channels of AES/EBU input, and 8 channels of balanced (XLR) analog output as well as a headphone output.

Two of the followup reviews that were published in the November 2020 issue of Stereophile have been posted to the magazine's website: Herb Reichert on the Yamaha A-S3200 integrated amplifier and the measurements of the Denafrips Ares II and Terminator D/A processors.

The email from Herb Reichert was intriguing. "I am, with great difficulty writing about HoloAudio's new two-chassis May DAC," he wrote. "It is death quiet and very natural. It makes every recording sound non-digital."

Once Herb had finished writing his review of the HoloAudio for the August issue's Gramophone Dreams column, I sped to his Bed-Stuy bothy and grabbed the May DAC, both to get it on my test bench and to take a listen for myself.

I felt like I'd just been offered a choice of 31 flavors of Baskin-Robbins ice cream topped with up to 57 varieties of Heinz ketchup, 57 condiments, and 47 brands of coddled cream. My head began to spin, my stomach churned, and my mouth grew very dry as I read that Gold Note's DS-10 ($2995) was a "chameleon DAC" with 192 setup options that enable it to "completely blend in with different music genres, giving the listener the opportunity to adapt the behavior of the unit to the music playing, to one's stereo system and, most of all, to the listener's taste."

Hi-fi system resolution has long been the cause of heated arguments. But when it comes to converting digital data to an analog signal, there can be no argument. Data go in at one end of a DAC and an analog signal comes out of the other end, with a noise floor directly rated to the combination of the converter's digital and analog resolution. Ever since I started measuring digital products for Stereophile, I have been expressing a D/A processor's effective resolution in terms of the equivalent number of bits.