Charles Hanson of Ayre has never offered an external DAC in his company's sixteen-year history. Now, however, he decides to unveil a USB-only DAC for PC audio systems. What gives? Well, if you are so inclined, you can spend some time at the Ayre website and read the white paper that defends his position, which is that external DACs are inherently flawed and, until now, a single-box player was superior. As an electrical engineer, I must say that his argument makes a lot of sense from a technical perspective. Rather than bore you with those details, let's get down to what you really want to know: how does it sound?

I just got a chance to hear the $2,500 QB-9 DAC in a system that I am very familiar with, which includes the Ayre KX-R preamplifier and MX-R mono amps driving Rockport loudspeakers through Ayre signature cabling and various high-end power conditioners. Now that you know there can't possibly be a more synergistic environment for the DAC, I can tell you without hesitation that it was staggeringly good.

I sampled a large variety of music and never heard anything that seemed to challenge the QB-9. Regardless of what it was playing, it was utterly natural and recreated timbre especially beautifully. I listened to a saxophone solo, which was just jaw-dropping. It was absolutely filled with texture and nuance. Vocals were equally impressive and it was easy to forget that I was in a living room and not at a live performance. Bass performance was rock-solid, yet again very well-articulated and detailed. Some credit for this must be given to the MX-Rs, however. Treble was airy and sparkled, but never aggressive.

The soundstage was wider and deeper than I had ever heard this system. It was so wide, in fact, that I felt immersed in the performance rather than as though I was simply hearing it. Instruments and performers were placed with absolute precision in all three dimensions, even at the extremes of the stage. The QB-9 was able to retrieve enormous amounts of detail from the data stream, but they were presented in a manner that was completely natural, unlike some hyper-detailed sources I've heard. The system's performance, from the deepest bass to the most shimmering cymbal, was very consistent and very difficult to fault.

High Points
- The Ayre QB-9, in this system, gave one of the most natural and lifelike performances I've heard. It is an excellent performer from top to bottom, but truly excels in reproducing the natural timbre and textures that blur the line between live and recorded music.
- The soundstage that was created was full, rich and enveloping. It was a joy to listen to and pulled me deep into the performance.
- Throughout the entire listening session, the QB-9 never experienced a single glitch while communicating with the MacBook. As a PC user, I was quite impressed by this, as my experience with USB devices has not been confidence-inspiring. The owner of the Mac seemed amused by this.
- Build quality is typical Ayre, which is to say it's to the absolute highest levels.

Low Points
- As stated earlier, this is a USB-only DAC. There are no other digital inputs and the reasons for this are discussed thoroughly in the Ayre white paper. However, I would be willing to give up some performance on a coax input to be able to use a DAC like this for additional sources, provided the USB input remains the same.

Conclusion
The Ayre QB-9 USB DAC is a very impressive piece of equipment. It recreates music from an ordinary laptop, which will go toe-to-toe with some of the finest digital gear on the planet. It is utterly natural and creates a soundstage so lifelike you can almost walk into it. I have no doubt that this DAC would be outstanding in any system, but the way it works with an all-Ayre system was unbelievable. Yes, I want one for myself now.