Recommandation for 1:6 1:8 SUT under $5K?

Although the guy in Elliot's video seemed to be a bit odd, it seemed to me he might be saying that there is an attenuator in his device that operates by the photoelectric effect, rather than by simple resistors. But still....

lewm

not seem to say, he is saying, and showing with a turn of the knob

"this is just two transistors, optically powered"

he describes "nice resistors, nice capacitors" ("new organic polymer, I don't know"), so they are involved in the audio path

he calls the dimmer/attenuator a 'regulator'

1. you turn the 'regulator' knob (not in the audio path)

2. dimmer makes LEDs emit more or less light (also not in audio path)

the wired path

3. pair of light sensitive diodes pass more or less juice via wire to:

4. pair of transistors that make more or less gain via wired input from the photo diodes

thus it is not mutually inductive like most SUTs; within his chosen range it is an infinitely adjustable valve, light controlled

from wiki

"A voltage or current applied to one pair of the transistor's terminals (input from the cartridge) controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal."

now, what are the resistors and capacitors doing, he doesn't say, except that they are "part of the magic".

OP

turns ratio unknown, but this Audio Note SUT, AN-S4M has Silver Wire

M version is specifically made for cartridges with coil impedance of 7-9 ohms.

https://tmraudio.com/fresh-arrivals/audio-note-an-s4-m-mc-stepup-transformer/

https://www.audionote.co.uk/an-s4

..................................

Custom Silver Transformers

​

The internal transformers used in the AN-S4 are manufactured by Audio Note (UK) exclusively. Each transformer is made from 0.1mm laminated Super Mumetal 250 and wound with 99.99% pure silver wire. Each Transformer is then housed in a Mumetal screening canister to minimize noise and interference.

​

Low, Low / Medium, Medium and High versions

​

The AN-S4 can be supplied in the following standard versions to suit the internal impedance of your cartridge: -

​

AN-S4/L  - 3 Ohm input impedance - Primarily designed for use with the Audio Note (UK) IO range

AN-S4/LM - 12 Ohm input impedance - For cartridges with an impedance of 3 to 4 Ohms

AN-S4/M - 27.5 Ohm input impedance - For cartridges with an impedance of 7 to 9 Ohms

AN-S4/H - 48 Ohm input impedance - For cartridges with an impedance of 12 to 16 Ohms

Elliot, I know how it works.  His way of describing it is emblematic of what Einstein is supposed to have said, to the effect that an hypothesis to explain a scientific observation should be as simple as possible, but not simpler.  I don’t really know whether Einstein ever uttered words to that effect; it could have been Yogi Berra.

In my opinion, the person who first adopted the custom of labeling SUT inputs with resistance values (ohms) ought at least to have spent a little time in a bad place, as punishment.  It’s diabolically confusing to the average end user. What you need to know is the turns ratio (in your parlance, the ratio of Voltage in to Voltage out, or vice-versa).  Period. From that, it is a piece of cake to determine the impedance seen by the cartridge once you also know the value of the input resistor on the phono stage.  You don’t need no stinkin’ tables.

On the pages you referenced from the AudioNote UK website, nowhere can I find the turns ratios of the respective transformers.  What is the rationale for the ohmic designations they provide for the various versions of SUT, as quoted by you above? They really don’t say on the website.  They want no questions from the buyer; just do what they say and pay your >$5000 for it. A transformer by itself has no impedance except that of the resistance of the primary. So, in isolation, a resistance value means nothing.