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If the is a place you could feel an amp held up over time would be in a tube amp, where there was a certain sweetness (not accuracy) that was particularly appealing. Or if you are not actually appreciating better more accurate performance. Over the last fifty years solid state more closely approached the positive attributes of tube gear and tube gear more closely approached the position attributes of solid state gear, converging on best possible sound... as refinements in material science and component construction and selection will continue. I suppose the state of the art will level out at some point, but it sure has not yet.
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I guess it is great that some people feel this way. This is how I got the same price in trade in as I paid for my Pass x350 16 years earlier. I got a ridiculous amount of money back for my Threshold as well, on a sound / dollar basis.