I don’t really think the P3 is viable as a tube headphone amp, didn’t like it in that role at all, totally underwhelming. As a compliment to the V3, in what would seems an unnecessary pre-amp role however, it seems to perform some kind of voodoo magic! After an afternoon comparing V3 on its own, to ICEPower 125asx2 kit I’ve just built on its own, to both with P3 installed between these power amps and DAC has been enlightening.
Obviously I can’t do this blind, and it takes a while to swap cables etc, but with volume matched results were very interesting. The ICEPower (at three times the price!) was overall uninspiring, if nice, comfortable, perfectly ok. The P3 on its own was immediately more dynamic, interesting and impressive - if a little ‘in yer face’. The ICEPower with the P3 as a preamp was bland and boomy, but the V3 with the P3 was altogether more listenable.
There was no loss of detail compared to on its own, lots of dynamics still, just somehow it all hung together better. Perhaps the easiest way to describe it is if instead of a wall of pristine data, individual strands of the mix seemed to be picked out and presented forward, leaving other background detail, well in the background?
I don’t necessarily attribute this to the tubes, it may well be an impedance issue between the DAC and the V3, maybe the P3 is acting as a buffer? Anyway, it stays in and I’m keen to play with other budget Class D amps and maybe build the next one with a variable buffer maybe?