SUT - electrical theory and practical experience

Dear @intactaudio : The " trouble " is that you mate the owner cartridge to the SUT, so your SUT units are not " universal " and that’s something normally we are not accustom too but even that and through those sample measurements I can’t seen in any a condition where your SUT goes flat from 10hz to 200khz as Denon or 3hz to 300khz as Technics or 5hz to 170khz as Supex or today At that goes 10hz to 200khz at 3ohms.

Btw, you posted:

" When considering phono playback, nothing of value exists below 20hz. "

Really?, now I understand why those measured graphs by you.

@karl_desch Perhaps your friend runs tubes down there but if your 27 is noth good enough then is time for you can think to change it for the EMIA, could be a good alternative.

R.

As I said, your lines only bs.

Your frustration is so high ! ! 

R.

intac, btw maybe you think the same over 100khz.

Each one of us have our self way of thinking.

You said in your site:

" The transformers are wound on massive.."

and the " Shipping weight - 11 lbs. [5 kg] "

Well Denon net weigth ( not shipping. ) is  12kg and 8kg for the vintage AT 1000T. Those are really massive.

But as I posted , no one cares about or just does not the knowledge levels for.

R.

@rauliruegas 

Blindly parroting frequency numbers without clear designation of the related decibel level is an effort in futility.  In looking at the 3-200kHz number of the Technics you reference (SH-305MC) there is no designation of the attenuation level at the specified frequencies, They do state 20Hz to 100kHz ±0.2dB but fail to state the exact test conditions (source Z, Load R and C).  The Denon AU-1000 states 5Hz to 200kHz but also lists no other test conditions.  The Frequency response plot I found shows it to be -2dB @ 5Hz and -4dB @ 200kHz again without specifically listing the complete test conditions.  One could assume  that the source is 30Ω and the load 50kΩ and there is mention of a low capacitance accessory cable so that is more info available than the Technics. 

For any design it is easy to find and publish the optimal wide bandwidth conditions for great measured response but absent the full details of the test condition, the numbers become meaningless.  If the underlying numbers have no real value, then any presumptions based on those numbers also lose validity.  I also fail to see how you can consider both of these transformers to be "flat" for the bandwidth you quoted yet fail to see the ±1dB response from 10Hz to 230kHz of the EM/IA 1:20L driven from a 9Ω source and loaded with 300kΩ in parallel with 80pF of capacitance.

I do want to be clear that I do not think frequency response should be the sole dictator of "quality" of a SUT.  Bandwidth is just one parameter of many that has to be addressed in a given design. In fact assuming the frequency response safely covers the audio band,  I find core material, dielectric choice and winding wire to be far more dominant factors in the final sound. I find extending bandwidth (particularly at high frequencies) is simply more icing on an already delicious cake.

Elevating the merit of a SUT based on a single ambiguous parameter as you do is like purchasing a sports car because it is a pretty shade of red or has a lower curb weight than the competition.

dave

Raul, to state the bandwidth of any transformer, particularly an audio SUT, without specifying the upper and lower limits of the given bandwidth in db, the impedances on the primary and secondary windings, and the other reactive components of the load, like capacitance and inductance, is fairly without meaning, I would think. But Dave said it more eloquently.  (I saw his post above when I was about two-thirds through writing this one, so what the heck; I'm hitting the "post your response" button.)