PS Audio PerfectWave DirectStream D/A processor More Torreys

More on the Torreys firmware upgrade from February 2017 (Vol.40 No.2):

In his report, in the November 2016 issue, on the Torreys firmware upgrade for PS Audio's DirectStream D/A processor ($5999), Robert Deutsch wrote that he had noticed "an increase in resolution"—and at that, my ears pricked up. I had purchased our original review sample of this processor following Art Dudley's favorable review in September 2014, and I had upgraded it, in the summer of 2015, to the Yale operating system, which I prefer to the earlier Pikes Peak and v.1.2.1 versions. As much as I enjoy the sound of the DirectStream, I had always been bothered by the fact that its ultimate resolution was limited by its analog noise floor.

According to PS Audio, not only does the Torreys upgrade enable DirectStream DACs with the optional Bridge II network card to act as an endpoint for the Roon music management system, Torreys "further reduces DirectStream's sensitivity to jitter, and adds proprietary resource-management within the [Field-Programmable Gate Array]. Other advancements include better low level linearity at low volume levels; improved gapless DSD support; improved sigma-delta modulators; and improved high-frequency noise performance."

I am not a Roon user but these other benefits sounded tempting, and I installed Torreys on my DAC. The necessary files are packed into a Zip container that can be downloaded from PS Audio's website. After the files are unpacked, they are copied onto an SD card which is inserted into the appropriate slot on the DAC's rear panel, with the power off. When the power is then turned on, the DirectStream loads the new firmware from the SD card. After the installation, you can check that it has been correctly installed by pressing the gearwheel icon at the top left of the front-panel display.

Fig.1 PS Audio DirectStream, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS DC–10kHz, with 24-bit data with Yale OS (left channel blue, right red) and Torreys OS (left green, right gray) (20dB/vertical div.; linear frequency scale).

Before I did any listening, I performed a full set of measurements with my recalibrated Audio Precision SYS2722, but to my surprise, I didn't find any differences. Fig.1 shows the spectrum of the DirectStream's output with the volume control set to its maximum with a dithered 24-bit 1kHz tone at –90dBFS with the Yale OS (blue and red traces) and Torreys OS (green, gray). The two sets of traces overlay exactly.

Fig.2 PS Audio DirectStream, spectrum of 1kHz sinewave, DC–10kHz, at 0dBFS into 100k ohms with Yale OS (left channel blue, right red) and Torreys OS (left green, right gray) (20dB/vertical div.; linear frequency scale).

Similarly, the spectrum with a full-scale, 24-bit 1kHz tone with Torreys (fig.2, green and gray traces) was identical to what I had found with Yale (blue, red), even down to the very low-level 100Hz-spaced sidebands around each harmonic.

But when I listened to the PS Audio with the Torreys firmware, while the DirectStream DAC didn't have the low-frequency authority that makes the dCS Rossini Player I reviewed last December stand out from the crowd, I had to agree with Bob Deutsch. Even without greater measured resolution, it did indeed sound as if there was more resolution. I switched back between Torreys and Yale and back to Torreys and the impression of greater resolution with Torreys persisted. A paradox.

I wrote in a follow-up in the March 2015 issue, where I had found that the v.1.2.1 firmware had given measurable improvements in performance over the original v.1.1.4 firmware, "The new firmware is a gift to end users that will keep on giving." Torreys is another such gift.—John Atkinson

jazzbirder's picture

I am having some problems with the new P S Audio DirectStream DAC I bought. I am not a audiophile or a computer wiz. I have an old Dell from 2004. I called P S Audio to help with downloading the software and fired up the DAC. Using my USB cable, I was able to listen to WBGO on the net, but I could not listen to WKCR because Windows Player and Real Player gave me error messages ! I need someone who knows audio and PCs !

John Atkinson's picture
jazzbirder wrote:
Using my USB cable, I was able to listen to WBGO on the net, but I could not listen to WKCR because Windows Player and Real Player gave me error messages!

As you were able to listen to WBGO via your Internet connection and the PS Audio DAC, this suggests your set-up is correct. If you set the PS Audio via USB as your PC's default sound device, are you able to listen to things like YouTube using your Web browser?

John Atkinson
Editor, Stereophile

John Atkinson's picture
dcolak wrote:

Thank you for the link. Amir's measurements aren't that different from Stereophile's, so I am not sure why you imply ours aren't "real."

In addition, when he quotes me as saying in our review that "In many ways PS Audio's DirectStream DAC measures superbly well but..." and says "What? Superbly well? This is is superbly well?" and shows the poor low-frequency linearity graph from my measurements of the review sample with the original firmware, he is ignoring both my "but" and the subsequent measurements at, which show that this poor performance had been addressed.

John Atkinson
Technical Editor, Stereophile

Jarek Htaudio's picture

Tego DAC będzie można posłuchać w tym tygodniu w Poznaniu w HTaudio w ramach "Tygodnia z najlepszymi przetwornikami DAC w cenie 18-30 tys. zł". Oprócz PS Audio DirectStream DAC będzie także Nuprime Evolution DAC, Audiobyte Hydra Vox i Simaudio Moon 390: log/zapraszamy-na-tydzien-z-na jlepszymi-przetwornikami-dac-1 -6-sierpnia