I have had both, and would lean toward the Pass Labs, but hey do you want to know what these were traded to me for? Belles 350-A at a recently increased price of $4000 new. Reviews will easily support the fact that these are regarded as the finest amps at any price let alone the bargain price they list at. These are different by way of being almost tube-like in their smoothness, and are remarkably natural sounding, but most noticeable is their involving nature, you like them more and more as you listen to them. They are dangerous to your free time of which there isn't enough of.
Keith
Keith