Digital Processor Reviews

Three products were recently subjected to second opinions: I reviewed the revised RS250A version of HiFi Rose's RS250 streaming D/A preamplifier and the optional DC1 DAC module for Audio Research's I/50 integrated amplifier; Ken Micallef wrote about his time with the Volti Razz loudspeaker.

I reviewed the original HiFi Rose RS250 in December 2021. I wrote that this is "an extraordinarily versatile, affordable product" and that its sound quality suggested that nothing had been compromised in packing so many features into its small chassis. "Highly recommended," I concluded, "both as a streaming DAC and as an all-in-one hub for a high-end audio system." The RS250A ($2695) replaces the RS250's ESS ES9038Q2M two-channel DAC chip with the higher-performance ESS Sabre ES9028PRO chip and now supports PCM data formats up to 32/768 and DSD formats up to DSD512. I both auditioned the new version and performed a set of measurements. The result was that I extended my earlier recommendation to the new RS250A. "It is an elegant-looking, well-engineered, multipurpose component."

When I reviewed the Audio Research I/50 in September 2023, this tubed integrated amplifier ($5500) only had balanced and single-ended line-level analog inputs. Toward the end of the review period I was sent the optional DC1 DAC module, which adds $1000. As well as coaxial and optical S/PDIF inputs, this module has a USB port and a Bluetooth antenna to allow streaming from computers and smartphones.

Listening to CD data, the DAC module's tonal balance was a little darker than I was used to with the I/50 handling analog data. With hi-rez files fed to the USB input, kickdrum had slightly better articulation than CD and the overall presentation had a little more space between the instruments. Measurements indicated that the digital inputs have a resolution close to 18 bits. I concluded that the DAC module adds value to what is already a relatively high-value tubed integrated amplifier.

Tom Gibbs reviewed the Volti Razz loudspeaker ($7500/pair) in August 2020, writing that this three-way, high-sensitivity, hybrid-horn design's ability to portray music of any genre with scale, realism, and thrilling dynamics was unmatched by any loudspeaker he'd had in his system. "The Razzes demonstrate a lovely midrange liquidity, but there's no sacrifice of detail," he concluded.

Ken Micallef had previously reviewed Volti's more expensive Rival speaker in June 2017, so spent some time using the Razz, driving it with both tubed and solid state amplification, in order to offer a second opinion on its sound. "That second opinion can be useful for readers—new experience in a different room with different ancillary components and a different set of ears," he wrote about FollowUp reviews in general. He echoed TG's recommendation of the Razz, deciding that its demeanor seemed very much the same as that of the Rival, "just on a smaller scale, with the same balanced sound, even temperament, and genre-agnostic capabilities . . . The Razz will get you close to the Rival experience for considerably less money."