Amp Specs esp. DampFactor : Citation, Adcom, etc.

Kijanki, would this explain why some have argued that keeping the signal above 20kHz is still necessary even though it isn't audible in the 'traditional' sense? Or is that what you're saying and I'm just repeating it? :-)

Thanks, Aaron

Aewhistory, I had impression that keeping bandwidth well above 20kHz prevents phase shifts within 20kHz but as research suggest it might as well improve transients that our brain processes.

Technical spects have no value to me. I'm not even sure what they mean. Is low THD amp better sounding than high THD amp? Same goes for DF.

To me, at least theoretically, a low THD should represent a cleaner signal path. Of course, this is theoretical, but what that spec. means to me is that the amplifier is not introducing outright distortion into the line. Of course, having said that, what constitutes distortion needs some definition.

This may seem completely unrelated, but in my field, history, the same types of arguments are made over trying to define terminology, categorizing, measuring, etc. And the results are no less frustrating. So while I can't claim to understand the finer aspects of EE, I do understand the academic aspects of the debate and appreciate them, despite my somewhat simplistic approach.

Yes, THD should represent a cleaner signal path but the problem is that amp design is a compromise - you want more of this you'll get less of that. THD is usually traded in SS amps for TIM and related odd order harmonics enhancement. Stereophile experimented with Cary CAD-805C amp that has adjustable feedback and found sound to be natural without the feedback (where THD is higher) and "Hi-Fiish" with deep feedback: http://stereophile.com/reference/70/

I'm not sure what can be useful in amps spects. RMS power ratings has some value but I can imagine two amps with the same RMS power rating where one can play music much louder (bigger overhead). It is like trying to classify a taste of wine. I'd like to know if it's red or white, dry or sweet but everything else is very subjective.

Aewhistory, for the most part I think you will find that a low THD indicates a greater amount of feedback (with it accompanying distortion of the 5th, 7th and 9th harmonics) rather than a 'cleaner' signal path.

IOW, if anything it appears that there is a loose correlation saying that higher THD will sound *better* not worse- and likely having a 'cleaner' signal path, hence less need for feedback. The 'cleanest' signal path will have no need for feedback. Note: this is neither a tube or transistor distinction.

Kijanki, IME wide bandwidth is important due to low phase shift, barring that, then gentle rolloffs as opposed to steep ones. I use an Alesis Masterlink in the recording studio for backup recordings. It can record at 88KHz, which is nice as when you use that mode, there is no brickwall filter. As a result the 44.1 KHz finished product does sound better on that account. I think things like this and what you just described are where the advances in digital are occurring- no doubt due to our improved understanding of how the ear works.