I guess I will note here that I have KM boards in stock.
If the rail harmonics are audible in the output of the amp, then using a PSU with less harmonics will help. The KM would be better than the Darlington in this regard.Keantoken, im debating on whether to use this or the typical darlington cmx for my class a headphone amp. Reading up on pros and cons of cfp vs darlington it seems to me that cfp is harder to stabilize vs darlington having more 2h, at least in the output stage. But also i remember seeing that the transistor characteristic of an active psu will show up on the load. Then since darlington has more 2h, can we assume that as a cmx the same characterstic will be heard on the final sound?