I was reading this review of Henry DAC. My interest from this unit comes from the fact that unit's schematics and code are open source! IMHO, that is pretty cool. Sound on the other hand remains to be seen... And btw, has anyone ever tried this unit? I am seriously considering buying it just to satisfy my curiosity. Another thing that stuck with me was this claim from the unit designer: "ESS don't make their products available through typical electronic parts distributors. Getting them in low volumes was a big hassle. But what made me choose another chip was the discovery of an internal math bug in the ES9022/9023. A >-1.3dB full-scale square wave played through their chip will generate great amounts of distortion. With modern compressed music, that isn't just a theoretical occurrence. I worked many years with signal conditioning and was able to see what goes on. In technical terms, the internal FIR filter does a 2's complement overflow where a very positive number actually flips around and becomes a very negative number. This occurs before the sigma-delta modulator. A digital limiter or lower gain in the FIR would solve this." I do not understand the technicalities of how that works, but it seems like a pretty big oversight from ESS. And can it really affect music since he mentioned square wave and "great amounts of distortion", and more importantly has someone else noticed this? Maybe someone with intricate technical knowledge could shed some light on this?