What is wrong with negative feedback?

When I first heard the IcePower amps in my setup, the difference in the nature of teh sound from anything I had heard prior was most startling. It was most apparent in that major volume adjustments seemed to have comparably little effect on volume, though the SPLs were clearly increasing as expected.

My observation of how the IcePower amp sounds as volume is increased seems consistent to me with what Ralph describes as the benefit of not using feedback and loudness cues. Most really good systems I have heard over the years tend to behave this way more or less I believe.

At the same time, Icepower applies negative fedback clearly. So I have to conclude that the IcePower amp has achieved a lot of teh benefits that Ralph attributes to no feedback in its specific implementation.

If so, another reason why Icepower/Class D can be considered a major innovation in home audio along with the other advantages.

Kijanki, I could be wrong about this, and perhaps it doesn't matter, but, I don't think Ar_t 's amps were ice amps.
Have the TacT amps changed since then?

Acoustat6, yes, sometimes I do. Most music does not demand it but some does: The Verdi Requiem, on the Soria box set (RCA) is a good example of vinyl being put the limits, and stereos too. If you play the quiet spots at the correct volume, the peaks will be at 115db.

So- to answer another question- 115 db peaks occur front row center, equivalent to where the microphones are usually placed. When you are in the orchestra, you don't get the same volume exposure that the audience does unless you are in the percussion section.

Some of the class D amps do not have feedback as well as some transistor amps as I have mentioned. Some of the class D processes allow for time manipulation, which is a fancy way of saying that they have a way around this issue. I don't doubt that this may be part of why class D amps are challenging the traditional transistor art.

However the artifacts I am talking about also occur at much lower levels. BTW, it is odd ordered harmonics that allow SETs to have the 'amazing dynamics' that are so often associated with them despite their low power levels. When an SET is at low power, it makes no odd orders at all, but when you push it over about 50% of full power or so, they begin to show up. Since it is the transients that take all the power, that is where the loudness cues are now occurring too. As a result, an SET with low power might seem to play so loud that 85 or 90db seems like a lot. This is the effect of artificial enhancement of the natural loudness cues.

As a result I am careful about using the word 'dynamics' because so often when I hear audiophiles use the term they are really talking about 'distortion'.

If you can't be in the room with musical peaks at 100 db (if its uncomfortable or sounds too loud), then its very likely that the odd orders are being enhanced.

Unsound - I remember Ar_t posting on the subject of switching amps. I don't know about TacT now. At the time I bough my Icepower based amp I read opinions on Icepower and Hypex. Both configurations (Full Bridge vs Half Bridge) have good implementation for instance Hypex based Channel Island amps.

Mapman - I also observed that listening at low volumes with Icepower is very good. I know that part of the problem is our hearing but I enjoy very good and clean sound (with very articulate bass) at low levels without any loudness correction. I cannot explain it. Do you experience the same?

"Mapman - I also observed that listening at low volumes with Icepower is very good. I know that part of the problem is our hearing but I enjoy very good and clean sound (with very articulate bass) at low levels without any loudness correction. I cannot explain it. Do you experience the same? "

Yes, bass is very articulate at all volumes. That and the loudness behavior I described above are perhaps the two biggest differences I hear on my system with icepower compared to prior SS amps.

The loudness perceived compared to actual SPL was most dumbfounding at first especially in that teh IcePower amp power spec is 4X what I had before (500w/ch into 8 ohm compared to 120w/ch prior). Its almost like the additional power is utilized to flush out the music, kind of like blowing up a ballon, as the volume goes up yet the perceived loudness does not increase so much.

Kijanki, one other thing, with my particular speakers, the high current and efective doubling of power into 4 ohms helps produce a natural balance in the bass which also helps at low volume whereas with some amps, the bass is relatively leaner. Toss in teh articulation in the bass provided at all levels then and you have quite a winning combo that not only delivers a detailed low end, but also allows higher frequency details to come through to boot. Very satisfying to listen to! Articulate, detailed and "musical". Very hard for me find fault at present, which is a very nice place to be!