10-10-15: NonoiseI agree Nonoise. I stated this in another thread not too long ago & was challenged by the fellow who makes the Lightspeed Attenuator preamp (the one that has optical coupling for signal propagation). He insisted that it was the preamp & that I would surprised it was the preamp hence his design effort to minimize the distortion from it. He pointed me to his white paper which was an OK read. I figured it would be a pissing match if I countered his argument.
...... Having said that, the biggest distortion generator in the audio chain is the speaker. Hands down.
In the end, I also agree speakers are the worst offenders but I learnt that not everyone agrees on this. This surprised me as it's so easy to hear the distortion thru speakers esp. if they are not time-coherent (which 99% in the market are not). Anyway, just a side comment FWIW.