koetsu

roberjerman
09-11-2017 9:36pm
I recommend a moving coil step up transformer (SUT) for use with any low-output (less than 1 millivolt) mc cartridge.

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.

Yikes!

@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 :(

@chakster
That is the million dollar question. I have an Ikeda Kiwame (0.15mv) & Dynavector Karat Nova 13D (0.12mv) and have tried many options over the years.
Tubes - noisy but preserve timing
Fets - grainy/opaque
Transformers - low noise but act as tone controls, timing & coherency skewed

Most successful for me have been a custom head amp using bipolar devices and another unit custom designed specifically for a Highphonic cartridge ( 0.12mv ) using Burr Brown chips which are not available even to manufacturers ( they were research development chips for internal BB use only ). Both these units left my old Klyne System 7, Gryphon phono and many others for dust - grain free, transparent, ultra low noise floor. For LOMC cartridges 0.3mv and up its pure tube for me ( at 47k ) unless I need the extra gain. To be fair I have not heard current state of the art from Pass, Trinity etc so can’t comment whats currently available at that level.
In general, in my view, many reviews of LOMC’s more reflect the phono stage than the actual cartridge as really exceptional phono stages are few and far between.