Here is the web site for a much better power supply. I have one for my V-DAC.
I had one briefly and wasn't impressed. The sound quality after a couple of weeks was OK, but the real problem was the gain: the volume went from silence to unbearably loud very quickly. I'm much, much happier with the Creek OBH-11 I picked up to replace it. By comparison, the V-Can sounded hollow and shrill. And an "upgraded" Elpac power supply for the Creek can be had for $17.
Yes, I noticed the volume control would first bring in the right channel slightly before the left and I've learned this is normal. And yes, secondly, with my Sennheiser's, the volume would go from silence to screaming with a quarter turn of the volume pot. There must be some very hard to drive headphones out there!
I'm not sure what the load is with the Sennheiser is, I could measure it, but to what avail, I just need to get used to the pot and be careful. Dealing with 1/8 turn I would imagine frustrating. However, as I'm putting hours on the V-CAN it is starting to sound better. I think I'm going to keep it and deal with the volume issue, considering the low price I think it performs pretty good.
I'm finding as the unit continues to break-in the sound quality is improving. However, yes, the unit does sound a bit shrill. I'm going to give it about 150 hours to break in, which was suggested on another thread. Lastly, my dealer said a new upgraded power supply is coming out in about three months and less expensive than their current offering which can power three Musical Fidelity components. The new one (Ithink) powers one component and is a significant enhancement over the waa-wart.