I 've spent most of the day modding the X-CAN V3, focusing especially on the output stage. I ended up fitting bi-polar electrolytics (1000uF/16v), then bypassing them with the much respected Russian mil-spec PIO caps.
I must say I was dreading fitting these caps: they are, physically, huge and there's not much room on the V3's PCB. I decided to fit them on a bare piece of the curcuit board, towards the rear of the amp. I drilled two small holes and, with the help of some blue tac, secured the caps to the PCB with cable ties. All and all, pretty easy and not worth lossing any sleep over.
I have to say that the PIOs sound fabulous, even though they are not properly run-in. At first it rather strange listening to them. I mean, it's obvious from the start that they're better: the timbre of the music is excellent, and the music seems bigger, grander, flowing effortlessly from the headphones. It appears free from the harshness and grittiness of electrolytics, even the better quality ones. Stellabagpuss says these caps are "clearer", "warmer" and "sweeter", and I certainly agree with him. There's plenty of detail, but it's not "in your face" - it's all placed in that space between your ears, each thread of the music easily distinguishable from the other, without it being overly analytical or cold.
Simply brilliant.
Fergus
Next comes the X-DAC V3. Pray for me.