O2 design? Well it's quite good, BUT I don't think he achieved his design goal of "One size fits all" for various reasons:
For portable use:
- Too loud for (C)IEMs
- Channel imbalance at low volumes ( again for (C)IEMs )
- On/Off click is IMO not acceptable when used with (C)IEMs
- Way too big to be portable
- No charge/battery indicator. (How would I know when the batteries will suddenly go dead? I mean this IS suppose to be portable....)
For home use:
- No 6.3mm socket (some headphones need that and a 6.3 -> 3.5 is horrible interms of connector strain)
- No RCA inputs (most home rig would use that)
- IMO not very aesthetically pleasing (Which IS a criteria for me if I were to look for a desktop amp)
Overall, I'd say it's electronically practical but consumer-wise, not so much.
That's why people do projects in groups, not individuels.
Look at P-H for example, I'm only doing the electronic part which I'm good at, bowei did the management, and mech did the case design.
True true, I seriously wouldn't call the O2/ODAC portable myself, transportable yeah but not really portable in your pocket or so and yeah hate the design but one could just easily use wires to cable the dc jack and other unnecessary jacks on the front panel to the back or so.
Waiting for you to cook up a balanced amp soon, want to hear more bang for buck objective ss amp's rather than the other nonsense on the market like most of the Burson range.