SUT - electrical theory and practical experience

Dear @antinn  : The figures in the phonolinepreamp in my system was measured.

"   the amp becomes unstable. "

Not the one I own that was designed by a " genius ", not that really is a genius but his knowledge levels are at least at the same of any one of you and even could be higher than you can imagine. This is not bla, bla.

R.

Dear @holmz ​@lewm  : Good say it. Even almost all the OP links where full of science/math because as holmz and the op wanted is to UNSERSTAND it how it works and from where could comes or not the advantages.

R.

Dear @holmz ​@lewm ​@intactaudio : My Denon AU-1000 just arrived from its measurements I ask and what I receive of information is that this exxtremely special custom made for Denon Murata SUT transformers has a bandwindth ( my hard silver wired . ): - 1.35db at 3hz ( FR is the champ in tihis frequency range ) and totally flat to -2.5db at 305khz. It's THD 0.001 and noise levels -105db. I understand that the Murata is c0oper wired but superior to the silver Knondo and Ortofon silver wired too.. For me is really good this Denon. Unfortunatelly I did not ask for its rise time.

I own other Murata SUT’s as Entré and Denon AU-340 and even that the Entré transformers looks similar to the AU-340 exist a tiny differences in favor of the Denon, both transformers hard wired with same kind of cable.

Lewm as I told you , the AU-1000 is really near the direct connection to the MC in my phonolinepreamp and this speaks a lot of its quality performance levels.

R.

It looks like Bats are being catered for in the frequencies being presented and being a outcome of a Theorem presented.

@pindac The theory behind wide bandwidth in a zero feedback system has to do with filter theory. In a zero feedback system like a cartridge driving an SUT all the elements are passive so there is no correction.

To prevent phase shift (per filter theory) wide bandwidth is required.

Filter theory as it applies here:

Typically when a single frequency pole is present, it will induce a rolloff at 6dB per octave. Phase shift components of a 6dB slope will be induced down to 1/10th the cutoff frequency (the latter being defined as the -3dB point). That is why you see such wide bandwidths promoted in transformers, which typically have no feedback correction.

(As you may have surmised, if there is feedback correction the need for such wide bandwidth is reduced.)

So an SUT that cuts off at 50KHz will have some phase shift down to about 5KHz. The ear perceives phase shift over a range of frequencies although it cannot perceive it at any one frequency. Over a range of 5KHz to 20KHz where phase shift is induced by a 6dB/ocatve rolloff at 50KHz, the ear will perceive this as a ’darkness’ or ’slowness’; IOW a tonality is assigned. Conversely if there is an zero introduced at 50KHz rather than a pole, the ear will perceive this as a ’brightness’. So to maintain a neutral presentation, the bandwidth is important.

@pindac  : " 

The thread now is grounded with ones intention to attempt to impress their Mathematical Preference as being the better over another.

This attempt to hold centre stage, is being met by others, with a countering of this  very obvious intention at large, especially where the Math has been used as the support for the notion being proposed.

The Mass of Users of Devices as a Listener, do not care for such a Topic of Discussion. "

Who do you think are to came here and tell us what to post or not?, tghis is asother internet forums a free one to post what we want on the audio world.

So if you can go to other forums to preach. For me you are no one especial and only other audfiophile as thousands of thousands out there.

Your statements are TOTALLY wrong like it or not. If you don't like what you read here then just do not read it.Period.

R.