Bear. We all should be as lucky as you to hear silver and copper cables of identical geometries (what I referred to as "cabling patterns") in order to assess differences. The kinds of controlled conditions you employed are necessary to be able to make dependable predictions, such as how a cable is LIKELY to sound in one's system. Your expertise in this matter certainly speaks for itself. However, I have often enough heard TUBE gear with SILVER cables sound, not sweet on the top end, but painfully BRIGHT, GLASSY, and IRRITATING. I have also heard silver sound sweet, airy, and extended on tranisistor preamp/amp combinations. I still stand by the statement that one cannot dependably predict that B-E-C-A-U-S-E a preamp/amp combination is T-U-B-E (or ss), SILVER (copper) WILL work better. Not all audio salesmen (high end not excluded) are as knowledgeable as you as to WHEN the metal (silver or copper) emerges as a salient factor. I have had high end salesmen tell me that silver will be "brighter" without ever asking me what preamp, power amp and speaker combinations I was using. I have owned several different tube preamps over the last several years (Melos SHA-1, Audible Illusions L-1, VAC, Music Reference RM-5, and sonic frontiers SFL-2. The same silver IC inserted between preamp and power amps (VTL Tiny Triodes) did not result in a consistently, sweeter, airier, top end. Three of the six tubed preamps produced a sweeter, more extended high end with six nine's copper IC's. Just because all of these preamps were TUBED, did not mean they were all the same in input/output impedances, gain, frequency response, etc. In fact, WHERE and HOW the tubes are used in the circuit - as a buffer, in the output stage, etc. differs among "tube" preamps. Some tube preamps have more in common with SS preamps than other tube preamps, the tubes only performing a non-critical (tube) function in the circuit design. You are obviously aware of this, noting that SE (single-ended) tube designs differ from push-pull tube designs. In a SE design, where the tubes are a major factor for the character of the sound, just changing the output tubes can result in a desire to change interconnects to "soften" or "tighten-up" the high end or bottom end. The original question posted was a reference to a high end salesman's generalization (more like a universal) that ALL "tubes sound better with silver, and the implication that ALL "ss sounds better with copper", without taking into account that tube gear may have more variablity in design within its own "species". Some "tube" designs use tubes for "show" and are really nothing more than "camouflaged" ss designs. The point being that generalizations such as "tubes sound better with..." or "ss sounds better with..." are not really dependably reliable in helping us to select cables. The best thing a salesman can do in guiding us is to give us a bunch of cables of different geometries, to insert into our own systems, and let us and arrive at our own conclusions. I know of nothing in the sudio world that generates as much controversy as cables. In fact, many reviewers won't even review cables anymore because of all the variables that are involved.