David@davidberning.com: I understand that electrical damping, mechanical damping, amplitude linearity, transient response, loading characteristics, etc... are all different yet inter-related subjects. Achieving excellent results in one area may end up compromising performance to some extent in another area. This is where design variables come into play and the engineer / designer must do some juggling in order to achieve what they think will result in the best balance.
As far as your comments go about an amp with a negative output impedance, you are right, this is not that difficult to do. The end result would typically be a design that was highly stable into various loads, but not very linear in terms of transient response, dynamics and desirable sonics. Once again, there's a design trade-off involved due to the ( limited ) technology available to mankind as we know it today.
Having said that, i think that far too many concentrate on certain areas while neglecting others, resulting in equipment that might measure well under certain test conditions, but perform FAR less accurately / musically in the real world. That's because the product is not well rounded, but instead, concentrates on measuring / performing certain measurable tasks better than others.
If you would be so kind, can you refer me to what issue Stereophile reviewed the ZH-270 in? I know i have this issue, but haven't been able to locate exactly which one it is.
Atmasphere: There are no "perfect" amplifiers, so of course, NOTHING is "universal" by design. Having said that, some amps are FAR less sensitive to loading characteristics while providing more consistent performance from speaker to speaker and system to system.
Unless one is interested in working with "chameleon" components that change both electrical and audible measurements at the drop of a hat, selecting gear that is of a more "universal" nature makes building a reasonably decent sounding and consistent performing system a little easier. Otherwise, one runs into problems with crediting certain changes to one specific component ( or cable ) change, when in reality, that one change triggered other changes in the chain. This results in a cumulative effect, making it harder to both recognise and disect exactly what is going on and why.
When something like this happens, stability is compromised, resulting in a wider tolerance of potential results. There is also less potential to transfer said results into another system by following similar approaches with slightly different componentry. This is why so many "recommendations" here are NOT universal by nature, but extremely system and personal preference dependent.
An ideal amplifier would have an output stage that would mimic the load impedance that it sees on a real time basis, adjusting as dynamic conditions and frequency are altered. Such a design would require unlimited voltage and current potential with phenomenal transient response. We don't have anything anywhere near this, so all one can do is to choose the lesser of evils and shoot for some form of electrical consistency with pleasant sonic results.
As far as my belief / stated comments regarding your preference of speakers, i based my comments on the speakers that i've seen you set your gear up with at various shows. I had assumed that you would have selected support componentry that you not only find sonically desirable, but also brings out the best qualities of your gear. From what i can recall, what i have seen you working with under those conditions were all vented designs. Granted, show installations may not always be what a manufacturer would recommend under optimum installation conditions, but one would think that they would at least strive to deliver something close. Forgive me for making any assumptions in that area if i am mistaken. Sean
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