SUT vs. Phono preamp

Dear @terry9  @fleschler  and friends: That Audio Technica AT-SUT|1000 new top model says a lot for every audiophile and especially in the analog side:

In this thread ( and other threads through the time. ) I supported and posted that those vintage Japanese SUT's coming from Denon, Audio Technica and Technics are really even today second to none and contrary to today very expensive SUT manufacturers as Lundahl or Ypsilon and others the first hand knowledge levels coming inside those Japanese SUT's are way superior to the knowledge levels of today top SUT builders ( of course this is only my take. )

Audio Technica, Denon  and Technics all them were/are designers and manufacturers of: cartridges, tonearms, TTs and even electronics/speakers.
Been and be cartridge designers all of them ( including Ortofon. ) knows perfectly not only how works a cartridge but its needs and that latest Audio Technica SUT is a clear example of that when it comes with input/output balanced design:

""  The transformer maintains a balanced signal from the moving-coil cartridge through to the phono preamp...""

and I don't see there silver wire transformer windings.

Anyway, that AT SUT can be a must to liosten it.

R.

With a Moving Coil Phono cartridge, you should use an external Moving Coil (MC) step-up transformer into a Moving Magnet (MM) phono preamp or MM inputs, versus using a self-contained phono preamp that has both MM and MC inputs.

Background: Matching Moving coil Cartridges to phono preamplifiers is a difficult process. For MM cartridges it is relatively easy since there is a standard for MM cartridges which is 5mV output (at 1k Hz) and 47k Ohms loading. With MC cartridges, there is a wide spectrum of output voltages and internal impedances, as well as a variety of inductances. For a Phono preamp manufacturer, matching all moving coil cartridges requires some serious design considerations.

Basically, almost all MC phono preamplifiers have a MM mode. The designer in most cases, builds a second head amplifier or phono pre-pre amplifier to convert the signal from a MC cartridge to the MM level, where it enters the MM preamplifier. Most do this with an active head amplifier designed and built with FETs. Some use internal step-up transformers. The challenge is accommodating a wide variety of MC cartridges. This is typically accomplished using a set of switches or jumpers on a circuit board. Many have adjustments for impedance and output voltage (different gain settings). If you look at the specs of each phono preamplifier and compare them for MC cartridges vs. MM cartridges, there is usually a significant difference in signal to noise ratios, except for those that use internal step up transformers. For active head amplifiers going into the phono preamplifier, the ratio is lower by about 8-10dB for MC cartridges vs. MM cartridges. This results in a louder background noise floor for MC cartridges. Additionally, adding switches to low output signals degrades sound quality.

With phono preamplifiers that use internal step-up transformers, there is a limited range for MC cartridges, and typically, the internal step up transformers do not approach the quality of the best in the industry. One step-up transformer cannot be made to work properly with all MC cartridges.

A stand-alone step up transformer can be used to better match a cartridge to a MM phono preamplifier, instead of using the internal active head amplifier or the internal step-up transformers in a phono preamplifier. Step-up transformers ratios typically range from 1:5 to 1:40.

Adding an additional set of interconnects to use a stand-alone step up transformer instead of using internal circuitry inside a phono preamp does add some additional lengths of wire as well as connectors, however, the active stage or internal step up transformers are connected by wires or printed circuits inside the phono preamp. Perhaps one could also say that a console stereo or integrated receiver is better than separate components since no interconnects are required. That is true if you could choose which components are hard wired inside the console.

The bottom line is that you will get better result by matching a Moving Coil Phono Cartridge using a Step-up transformer with the correct ratio, than by using the Moving Coil section of a Phono Preamplifier.

I posted several times in other threads, that CURRENT-INJECTION type of the phono stage is something way different from conventional phono stages, headamps and SUTs.

For low impedance MC cartridges (under 5 Ohm for example) current-injection method is huge upgrade over SUT, traditional phono stages, headamps.

This is my first current-injection device (47Labs Phono Cube), i can imagine what more expensive current-injection phono stages can do.

Do not limit yourself with traditional solutions like SUT or High Gain Phono Stage.

Read more about Current-injection type of the phono stages for low impedance MC (most of the greatest MC are low impedance anyway).