[Nordo]

> Professional studio engineers will spend $3000 on a high-precision digital clock for their DACs because it makes a clearly audible difference.

I don't know what kind of frequency stability you really need (please enlighten me), but I checked on one of the components retailer websites, and found that even the most stable MEMS oscillators are only a few bucks a piece, any DAC or ADC manufacturer that claims that's worth a $3000 markup is running a scam.

> Software people don’t understand that human hearing, and human sensitivity to timbre and distortion, is spectacularly non-linear. Hearing isn’t a linear counting device with x volume levels.

As a "software person" I take exception to this. Who exactly of my colleagues claimed that it was? Not even the cheapest, most terribly sounding, incompetently designed child's toy's "what sound do cows make" 8-bit 8kHz DAC produces output with x discrete volume levels, it produces a continuous signal. A bad sounding signal perhaps, but a continuous one nonetheless. Plenty of software people know this, but do audiophiles?

[rcxdude]

The main kind of clock you can spend $3000 on is an atomic clock (usually a rubidium frequency reference). There's absolutely no point in this for an audio system, but it's a quite trendy money sink (especially because atomic clocks are if anything worse than a good crystal over short time periods and only dominant over very long time periods: if you need both you can combine them).