Originally Posted by upstateguy
But I have a better idea Phil, why don't you recount some of your "listener observations" so we might dissect them and delve into what happened.
Ok, I'll give you two, in the interest of brevity, that were meaningful to me:
1. When I was building my headphone-based system, I was using a copper interconnect from Better Cables to connect my DAC to my amp. I was thinking about moving the BC cable to another system, so I decided to try some other interconnects on a trial basis. I bought a higher-priced silver interconnect (about 4 times the cost of the BC cable) from a company I can't recall. I put it in my system one day before I went on a business trip, listened for a little bit, and then went to bed.
A few days later when I got back, I sat down for an extensive listening session. After a while, I noticed that my system sounded more harsh or sibilant that normal. I could not figure out what the problem was, but something was noticeably wrong. (I am pretty sensitive to sibilance.) I tried several of my favorite musical selections to make sure I wasn't hearing things, and was really annoyed at what I was hearing, especially because I had been spending a lot of time and not an insignificant amount of money trying to achieve a sound that I liked and could listen to for hours without fatigue.
I started eliminating possibilities, one by one, wondering if I was using my EH tubes in my tube amp instead of my NOS 6SN7's, etc. Finally, I decided to check the connections (my equipment is in a cabinet) to see if something was loose, or whatever, when I saw the silver interconnect I had put in before I left for my trip. I had completely forgotten about the change I had made.
I removed it, replaced it with the BC cable, and everything was fine again. No more harshness. I returned the silver cable for a refund.
2. For a long time, I owned the Bel Canto DAC 2. A really good DAC that I really liked. I came across a used Electrocompanient DAC, the ECD-1, at a small audio dealer's place when I was purchasing something else. I bought it on trial and spent some time listening to both DAC's. The ECD-1 sounded better overall to me. It had a better midrange and high end than the Bel Canto. However, the Bel Canto definitely had a better lower end, which I missed on several songs in particular. Indeed, a couple of songs which were my favorites when I had the Bel Canto were not nearly as fun with the ECD-1. There is no way the bass on the Bel Canto was precisely the same as the ECD-1. Overall, though, I preferred the ECD-1. In any event, I am as positive that the two DAC's sounded different as I am that the K-701 and HD-650 sound different.
Several months later, I had the ECD-1 modded. A definite improvement that anyone who had been listening to the stock ECD-1 for several months could not miss (most noticeably on piano). I don't think the THD or S/N ratio changed on the ECD-1 after modding, but the sound definitely changed.
There are other experiences also that have informed my viewpoint, but these are two that jump immediately to my mind.