When Art Dudley reviewed the original PS Audio PerfectWave DirectStream D/A processor in Stereophile’s September 2014 issue, he very much liked what he heard. “For those who’ve waited for a computer-friendly DAC that offers, with every type of music file, the best musicality of which DSD is capable, the PerfectWave DirectStream may be in a class by itself,” he concluded. It was computer-friendly because, with an add-in card, you could connect it with USB or to an Ethernet cable and use it with, for example, Roon or JRiver.
DSD? The DirectStream’s D/A conversion engine, designed by former Microsoft engineer Ted Smith, was unusual in that it synchronously upsampled all input data—regardless of format and native sample rate—to a 30-bit word length running at 28.224MHz followed by a digital-domain volume control. The data were then downsampled to 5.6448MHz, resampled to single-bit DSD128, and converted to analog with a low-pass filter.
Rather than using off-the-shelf chips, the DirectStream’s digital processing was performed by a field-programmable gate array (FPGA). The performance could therefore be enhanced by reprogramming this FPGA and supplying users with firmware updates. Art installed the first firmware update while he was working on his review, and several firmware releases followed, culminating in the “Sunlight” version in 2021. Robert Deutsch, Jim Austin, and I reported on the effects of the upgrades up to 2017’s “Huron” in follow-up reviews. I purchased one of the review samples in 2015 to use as my everyday DAC, fitting it the following year with the Bridge II network card in order to use it with Roon, and installing the penultimate “Windom” firmware
