Inner workings

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Have you ever peered inside a quality mechanical timepiece? Aside from the obvious workmanship to make the thing keep time, I cannot imagine designing and then crafting all the many gears, pivots, and jewels that make it tick. A typical Rolex has about 115 separate parts to its movement.

If we could take a similar look inside a modern DAC we’d see far more parts than the 115 of a Rolex. In fact, it’d be more like millions.

Modern digital audio circuitry is so complex that no one person could possibly keep a picture of its structure in their head—a block diagram, sure, but not the way a watchmaker can map every piece.

At the heart of most DACs are off-the-shelf chips, but their common architecture does not diminish their internal part count. Hundreds of thousands, often millions, of individual silicon structures open and close in concert to produce a single note of music. And in PS Audio DACs even more. Ted Smith’s creations are based on FPGAs (Field Programmable Gate Arrays) which start out like lumps of clay to a sculptor who can then program them into masterful art.

One question I am often asked is the importance of the DAC silicon itself relative to its other components like power supplies and its analog stage. The answer is, unfortunately, not simple. Like the watch example, the end result is the telling of time. In the same way, the end result of all that silicon is music in a form we can listen to. But how that music gets from input to output can be very important to sound quality. For example, much of the work Ted’s done involves complex math, filters, upsampling, and jitter reduction not common in other DACs. And while that is unique, the engineers at ESS who architect the internals of the Stellar GCD would say something quite similar.

And here’s something else to contemplate. The same DAC architecture attached to different analog stages sound remarkably unlike each other.

In the long run it all matters, but if I had to choose between DAC architecture and analog output stage as determining factors, I suppose I might argue the analog stage trumps all.

I have put together a few more rambling thoughts on the matter in this video which you can watch here.