koetsu

@dover

SUTs are a disaster for amplification of LOMC’s. Transformers have non linearities, particularly with regard to phase accuracy and are prone to ringing, it is not possible for a SUT based phono system to accurately reproduce what is on the record correctly.
Ringing muddies the sound and phase anomalies result is harmonics destroyed and sound stage distortions - the musical timing is lost.
Even the much vaunted Jensen transformers have to resort to zobel networks to try and tidy these issues up.
If you only listen to noise then by all means use a SUT, but it cannot produce music unless you consider music to be a series of distorted notes with no timing.

Damn, so how we should listen to 0,05mV Ortofon MC2000 cartridge then?

Without SUTs the volume on my amp turned at 12’oclock for late evening listening sessions, but it’s with 0.17mV Fidelity-Research PMC-3.

I don’t even tried to use my Ortofon MC2000 yet, i have this additional ZYX CPP-1 pre-preamp (headamp), but it was designed for 0,22mV cartridge. For the Ortofon MC2000 i was thinking about dedicated SUT :(

I don't know who is Arthur Salvatore, but this man tested many SUTs and posted on his website about it. He was a Koetsu dealer for 10 years. There are only a few SUTs in his "class A" category and his favorite is Bent Silver TX-103, my ZYX CPP-1 active headamp is the first in his "Class B" category and described as very close. He said: " For those audiophiles who don't like any MC transformer, for whatever reason(s), the ZYX is a no-brainer choice, if it's affordable."   

 

@nandric

If I remeber well you mentioned your ZYX CPP-1 at least 5 times

(grin).

Few times, yes, but seems like i’m still the only one owner here on audiogon. That’s why i always remember A.Salvatore.

When i did my search for "Denon AU-S1" on audiogon, i saw at leat 25 posts of yourself, so i hope you’re very happy about this SUT, lol
Another person who mentioned this was Raul, but only few times. BTW, correction: the impedance range of AU-S1 is not 2 - 40 Ohm, but 3 - 40 Ohm. And why i remember Salvator again is because his favorite Bent Silver SUT has similar construction (with direct connection to the transformer for each channel), but without the cabinet.    

Anyway the ZYX CPP-1 is not a SUT, but an active headamp, and considering Dover’s post (to avoid all the SUTs) i decided to remind about this device, hoping somebody else experienced with this, except Arthur Salvatore (ex Koetsu dealer) who rated it so high.

Well, i have transformers inside my WLM Phonata Reference MM/MC phono stage, but unfortunately this stage is also unknown to the members here. The construction of the stage is also unusual as it has "automatic load imedance for any cartridges" (not fixed load imedance like on most of the mc stages). Those transformers are very small, must be lundahl transformers, i screwed up my device when i changed 47k resistors for MM input (to vishay naked foil 100k).

I wish i could try more SUTs, because the gain on my MC stage is not enough for 0,05mV Ortofon MC 2000, but OK for 0,17mV FR PMC-3 as i said earlier.

And as the oppisite to the SUTs i have those headamp and additional JLTi phono stage with "high gain" to handle 0,20mV carts (not not high enough for 0,05mV carts like MC2000).

So it’s not the point to praise zyx headamp, but just a curiosity what is better and why.
For some reason (for the first time) i have hum when i use zyx with FR PMC-3, but when i use same cartridge with my WLM MC phono stage (with build in transformers) i have no hum.

I’m gonna continue my experiments with everything (SUTs, headamps, and high gain prono stages with plug in load resistors). At the moment i can’t say what is better. Sadly no one use the same gear here.

What i don't like about those external devices is that i need more cables and those cables must be top quality to avoid hum. Some cables what works fine for MM carts does not good for low output MC carts. 

I’ve come across @rauliruegas post from 2013 and his list of tested SUTs looks impressive (see below):

Dear Dover/friends: Maybe any one could ask: why me that always is against SUTs wants to test it again?.

Well, the at random finding at my place of those SUTs give me the opportunity to test it and to make something that I never try it: the SUT up to date.

I owned and heard a lot of SUTs in my system and in other systems.

I can remember some of them. From Audio Technica: At630, AT7000, AT1000, etc. from Ortofon: T30, T2000,T3000,T5000,etc. Luxman 8020/8030. Denon 320,HA1000, Pionner headamp. Two different Audio Note Kondo’s. Expressive Technologies. Highphonic. Dynavector DV6 ( or something. Classe NIL3 headamp. I owned 2-3 vintage SUT’s by USA designers that I can´t remember. Bent Audio and many many more.

In no one but the NIL3 I made any single up date.

-Raul

This Classe NIL3 is also in Arthur Salvator’s list, it’s funny @nandric but Raul’s farovite Classe N.I.L. headam was creamed by ZYX headamp in Salvator’s tests :)

A.Salvator said: "The Classe was the finest solid-state "head amplifier" ever made (until the ZYX CPP-1)." http://www.high-endaudio.com/RC-Step-ups.html
So i think Raul should try CPP-1, lol

Maybe i already have one of the best headamps, who knows.

The Audio-Technica AT1000T and AT300T, Denon AU-1s and Ortofon T2000 were in my wantlist for some of my LOMC, never tried them yet.