During the past several years, I've spent a large amount of time designing and building pre and power amplifiers, in an attempt to learn more about why different designs do sound different. During that time I've become more and more aware that subjective differences can arise from small (< 1dB) deviations in frequency response and also from small changes in the harmonic distortion balance. The old rule that odd is worse than even seems to hold true, particularly at high frequencies. A smoother, more velvety treble results if even order dominates and a cooler and more clinical or even harsh treble is obtained by allowing odd order to dominate. This rule seems to hold true even when distortion is <0.001%. It is also my opinion that what people are hearing when observing changes with different interconnect cables is little more than a small frequency response change due to cable capacitance. Higher capacitance can also increase the distortion produced by op-amp buffered CD players, and this distortion is generally 3rd order.
While I do believe that audiophiles can hear changes and differences that the average person cannot, I also concede that these changes and differences are often grossly overstated. Too many audiophiles seem to be caught up with small differences in sources and amplifiers. The 2 biggest contributors of distortion in any hi-fi system are : 1.) the loudspeaker, and 2.) the listening room. (IMHO)
While I do believe that audiophiles can hear changes and differences that the average person cannot, I also concede that these changes and differences are often grossly overstated. Too many audiophiles seem to be caught up with small differences in sources and amplifiers. The 2 biggest contributors of distortion in any hi-fi system are : 1.) the loudspeaker, and 2.) the listening room. (IMHO)