Aball's comment about "electron mobility being about a zillion times higher in a vacuum than in doped silicon" reminds me of something Bill Johnson once said about a signal going through a vacuum tube coming out unharmed while a signal going through a semi-conductor gets altered/harmed in various ways.
In practice when listening you can often hear that solid state equipment tends to harden and sharpen transients while closing in the ambient space of live recordings and obscuring the subtle textures of instruments. I assume that this is in part because a signal has to "fight" its way through a solid material in the case of a semi conductor and doesn't do so in a vacuum tube.
I've always intuitively felt that it's because of what Aball was referring to in his post that the sonic advantages of tubes over transistors exist even when the amplifier operates nowhere near clipping and also exist in preamplifier comparisons. IOW, there seem to be some intrinsic advantages to vacuum tubes apart from their distortion behavior.
In practice when listening you can often hear that solid state equipment tends to harden and sharpen transients while closing in the ambient space of live recordings and obscuring the subtle textures of instruments. I assume that this is in part because a signal has to "fight" its way through a solid material in the case of a semi conductor and doesn't do so in a vacuum tube.
I've always intuitively felt that it's because of what Aball was referring to in his post that the sonic advantages of tubes over transistors exist even when the amplifier operates nowhere near clipping and also exist in preamplifier comparisons. IOW, there seem to be some intrinsic advantages to vacuum tubes apart from their distortion behavior.