Onemangang's opinion does make sense to me when looking at a manufacturer's point of view. Kevin himself told me that he tries to use good tubes that are "readily" available. So from a "voicing" standpoint, he basically finds a good, readily available tube that works best in his circuit. He also mentioned that maybe 10% of the NOS tubes that he's experimented with might be better sonically than his stock tubes. He didn't tell me what those 10% were and I was reluctant to ask him. I guess tube rolling's the audiophile way, but it sure can get expensive in a fast way; but then again, VAC's stock tubes are pretty expensive, so what to do?
