The panel displays the incoming input signal, sample rate, and bit depth. Using the front panel touchscreen is intuitive allowing you to select inputs and change the volume (which can also be set to Fixed). Album art is only displayed via the network bridge. For album covers to display on the panel, you’ll need to leave the data card in place in the back, which is fine, that way you don’t lose it.
The unit will initialize for about 30 seconds while it loads the current software into the FPGA via an SD card in the back. The blue logo light on the front left side of the panel lights up and serves as the on/off switch. A master switch on the back places the DSD into ready mode. Functionality is controlled by a well-designed remote or via the 4 x 2-inch touch screen panel. The front of the unit has no buttons or knobs. The DirectStream is a fully balanced design. Outputs are either balanced XLR or unbalanced RCA. The PS Audio DSD has seven digital inputs two I 2S (pronounced eye squared S), and one each of TOSlink, coaxial, USB, AES/EBU, and a network input for the Bridge II module (which costs extra but came installed on my unit). The output DSD signal is fed directly into a stage based on high-speed video amplifiers (capable of handling the 5.6MHz signal) and a passive output transformer. This brings out more details and improves imaging.
Noise is pushed into the higher frequency band and filtered out via a passive low pass filter. The higher sample rate does not create new information from the original signal but allows for better filtering algorithms which allow for more of the detail of the original signal to come through. Going the DirectStream route, the signal goes PCM>DSD>analog. Interestingly, many of today’s PCM chips use sigma-delta modulation to get a DSD-like signal before analog conversion. In any case, why go to all this trouble? PS Audio is trying to extract musical information that can be masked by off-the-shelf PCM DAC chips. I’m not going to get into the DSD being one bit at very high sample rates, because that has been covered by SECRETS in the past. After processing, the signal is down-converted to double DSD, sent through a passive low pass filter and out as an analog signal. With me so far? That means the PS Audio DSD is upsampling the incoming PCM to 20 times the nominal DSD rate (20 x 64 x 44.1kHz) which is 56.488MHz (as in million). DSD256 would be four times that (4 x 64 x 44.1kHz). That means 64 times the sample rate of a CD (64 x 44.1kHz). The incoming digital data can be in PCM or DSD format which is then upconverted to 20 times the DSD sample rate prior to processing. This design offers the listener extremely low jitter as it uses one master clock for all incoming signals. Audio researcher and consultant Ted Smith is the guy who has handwritten the programmed architecture of the FPGA from the digital inputs to the passive output stages. I think of this chip less like hardware but more like a programmable software-type device. As a nuclear medicine technologist, I know there are some inside the gamma camera that I use every day at the hospital. This chip is used in many different electronic devices. The really unique aspect of the PS Audio DSD (DirectStream DAC) is that the core processor is not an off-the-shelf DAC chip from Burr-Brown, Wolfson, or Sabre, but a field-programmable gate array (FPGA).
There were also a few PS Audio decals that reminded me of the ones I got when I bought my MAC mini. Inside the carton were a pair of white gloves, power cable, aluminum-faced backlit remote control, a PS Audio catalog, and a very interesting, in-depth owner’s manual. I was loving my music collection again! That experience got me into pursuing better quality DACs in my continuing quest to reach that mythical sonic Nirvana.Įnter the PS Audio PerfectWave DirectStream DAC, which is a state-of-the-art-DSD digital-to-analog converter, preamplifier, and media center designed into a large, slick-looking aluminum and polished blackwood designed product with no discernable knobs or buttons on the faceplate. The sound had more dimensional energy, impact, and just sounded more alive. That sonic life really improved with the last digital preamplifier I reviewed earlier this summer and I attributed that improvement (amongst other things) to the DAC. I noticed sonic improvement with the time I spent recently with a powerful Class-D amplifier that really added punch and body to my system. I had chalked up the lifeless sound of my system to the new, larger room I had moved into, but now I realize that it was more likely tied to my long-in-the-tooth DAC. Recently I was reviewing a product that really upped the ante for sound quality and it made me realize that I was missing that chemistry I used to have for my music.