Walnut Cove, Asheville, Biltmore Forrest and Western North Carolinas Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

New DAC

I get few thrills bigger than launching new products. It’s what I live for… well… actually… listening to new improvements that lift the system beyond what I imagined probably trumps everything… but, what the hell, I love it all!

Today marks the official launch of a new DAC for PS Audio, the NuWave DSD. Without question, this is a huge step up in quality from any affordable D to A converter we have ever built. It’s really, really, good. No, it’s really, really great.

I won’t take your time to ramble on about how wonderful it sounds but I will mention just a couple of things that matter. This design has been a personal project of our chief engineer, Bob Stadtherr. He’s labored long to build the best sounding under $2,000 DAC he can and I am wowed by what he has wrought. Played on the newly dialed in IRSV in Music Room One, music puts a smile on your face and a tap in your toe.

The innards of NuWave are based on the excellent Sabre series of Hyperstream 32 bit DAC chips, but that’s not unusual. If it were not for DirectStream, I would wager the majority of contenders for best performance at any price are also based on ESS technology.

So what did Bob do to bring his magic to an affordable DSD platform? He added a type of FPGA to the front end. FPGAs, like those found on DirectStream, are the major workhorses of sophisticated technological equipment. Big FPGAs have millions of gates that programmers, like our Ted Smith, use to build the devices themselves – but that’s not what we did in the NuWave DSD. NuWave uses a smaller type of FPGA with a different acronym, CPLD, which stands for Complex Programmable Logic Device (these engineers lover their TLAs). CPLDs are basically smaller FPGAs and can be taught to do whatever programmers desire. Though too small to handle all the functions of a DAC, as we do in DirectStream, they are large enough to pull a few rabbits from hats.

Bob wanted to make certain that all incoming data, whether DSD, or PCM, was processed in the same way and then presented to the Sabre chip in perfect form and timing without jitter. To do that he spend much time programming the CPLD to identify the incoming format, organize the bits, and wave shape their output. Without going into too much detail, the custom gate arrangement on the NuWave DAC input has a great deal of impact on perfecting audio performance and as soon as you hear the DAC for yourself, you’ll start to get a good idea of what he has accomplished.

Tomorrow I’ll cover the second big advantage, passive filtering, and what it means to sound. If you want to read more details, click here.

Walnut Cove, Asheville, Biltmore Forrest and Western North Carolinas Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

Lucky breaks

When I described PS Audio’s beginnings I retold the story of building a phono preamplifier from a circuit I had gleaned from a simple textbook called The Op Amp Cookbook. At the time (around 1973 or 1974) it was the only easily understood book I could find at the local library. It wasn’t until many years later I realized my path had been altered by two lucky breaks: the author and the op amp.

The author turned out to be Walter Jung, an excellent audio engineer and contributor to the AES and who, along with Richard Marsh and others, helped hundreds of inventors, engineers and high-end companies realize their goals through education on the nature of circuits and passives. If memory serves correctly the two had much to do with Rel Caps, the same capacitors used in the BHK amplifier as well as its upcoming partner, the BHK preamplifier. Walt also authored papers on the effects of Transient Intermodulation Distortion (TIM) and Slewing Induced Distortion (SID) in his seminal paper. Who knew? In the early 1970’s that was the only book available in the Santa Maria public library, from a (then) unknown author. Some suggest fate, others luck, still others pre-destiny by a guiding hand.

The second bit of luck/fate/destiny was the choice of the actual integrated circuit. Turns out the type of IC op amp one uses has much to do with the sound as I have so often written in these pages. In those early days there were not many op amp choices available for easy access. The most popular op amp was the 741, an absolute hideous dog when it comes to audio. If ever someone from the flat earth society wanted proof that equally measuring amplifiers within a circuit sound different, the 741 would provide an excellent demonstration. Slow, sluggish, thick and flat sounding, this op amp was popular because it was internally compensated and just worked when placed into a circuit. Faster op amps, like the 301 – used by BGW, Crown and Soundcraftsman – was much better sounding, but never held a candle to the 709C. The 709C was introduced in 1965 by Fairchild and was invented by a man who had one of the biggest impacts on high end audio in the world, Bob Widlar. The 709 was fast, had great open loop and common mode gain with a robust output stage. At that time there were no better options, yet the 709C was almost never used for audio. In fact, it was an instrumentation amplifier and to my knowledge, PS Audio and Quintessence corporation were the only two companies to ever use it in audio. Again, how fortuitous?

That I found a book by an unknown engineer, who would later become one of the most famous in our industry, was luck of the good kind. That our station engineer happened to have the best sounding op amp of that era – and he had it to build a fast metering system (not audio) – and I asked just at the right time, another stroke of good luck. Without these steps, which led me to meet Stan, to build a family based audio company that survives to this day, I would likely be doing something very different.

It’s instructive to review what brought each of us to the fork in the road we find ourselves at today – and we can point to the steps and missteps that got us here – but it’s also natural to then ignore all the mistakes we made that played an equal role in directing our paths. Our mistakes are as important as our successes.

Never think, even for a moment, that your life’s path is set and will remain as it is right now. Hindsight suggests change is constant and all we can rely upon moving forward.

Embrace change, it is the only constant.