John Atkinson

Occasional Stereophile contributor Steve Guttenberg publishes a YouTube channel about audio that has achieved an impressive reach. As Steve told me in a conversation I had with him last December, 22% of his 98,000 subscribers (at the time we talked) are under 34 years old, and, to judge from the comments, most of them don't read Stereophile!!!! "It would nice to introduce you to them!" said Steve, and proposed he interview me and post the video to his channel when it hit the magic 100k number, which it did on January 9.

Steve visited my place in Brooklyn just before the New Year, and we spent an afternoon talking about audio, magazines, measurements, and music.

Even as digital/analog processors were becoming a hot product category in the early 1990s, audiophiles were also learning that timing uncertainties in the AES/EBU and S/PDIF serial datastreams—jitter—would compromise any improvement in sound quality offered by these DACs. Some companies therefore introduced products to reduce or eliminate jitter—in the November 1994 issue of Stereophile, Robert Harley reviewed three such products: the Audio Alchemy DTI Pro, the Digital Domain VSP, and the Sonic Frontiers UltrajitterBug. I still have Stereophile's review samples of the UltraJitterBug and VSP, along with two contemporary DACs: a PS Audio UltraLink and a Parts Connection Assemblage DAC-1.

As our reviews of these products were published before Paul Miller's and the late Julian Dunn's development of the "J-Test" diagnostic signal, I performed J-Test jitter measurements to bring that 1994 review into the 21st Century. You can see what I found here.

High-quality playback of digital audio is evolving in two opposed directions. One is where a smart wireless loudspeaker, like the KEF LSX or DALI Callisto 6 C, needs to be connected to a simple source of data. The other is where a smart amplifier takes the data from wherever it needs and sends it to a pair of dumb loudspeakers. NAD's Masters Series M32 integrated amplifier ($4848 with its optional MDC DD-BluOS module), which I reviewed in May 2018, is a great-sounding example of the latter approach.

In the spring of 2019, NAD introduced the Masters Series M10 ($2749). At first I assumed that the M10 was a stripped-down, less-powerful version of the M32, but the new amplifier offers a unique set of features.

"Stirring the stew" is what I've heard it called when a company introduces a new version of a product every three or four years. When a new product is launched, sales generally rise rapidly to a maximum and then slowly decline. If the stew is stirred every few years, plotting the product's sales volume against time results in a sawtooth wave, without sales ever dropping close to zero.