Headphones DAC

[floobydust]

I use 600 ohm headphones and two op-amps - one for the reconstruction filter and an second as a line driver.

I had a chinese Lehmann headphone amplifier clone, and it was total junk. It sounded annoyingly distorted and I found the usual- fake op-amps, and reject transistors, bad PCB layout etc.  I tried to fix it but the distortion was never as low as direct drive which is what I use.

[NiHaoMike]

The PCM1794A for instance is a "classic", and very good ($9.9 per 100 at Digikey). Supporting sample rates over 192kHz is IMO unncessary. No audio material is routinely available with higher than this anyway, and if you look at the figures carefully, you'll find out that the DACs supporting higher than 192kHz will have degraded performance for the higher rates. Not much benefit in practice.

Go for PCM1792A instead, almost the same except it has a built in PGA so you won't need an external one to set the volume.