I have tweaked PB5, because in my preferences, the PB5 has authority with amazing soundstage in addition of D16.
That is for hd800s as a full size. However, the lower base and it warmth with the analog fluidity performances are too much of a good thing. I tweaked it so that it is more neutral and sounding better in my own preferences
The D16 ? As you have seen
@purk posting above, I found that upgrading the output caps to Blackgate caps does a wonderful job when using D16 as a standalone device.
This is pretty much my preferences , so I am not developing any further mods