How do you move on the a SUT?

theoman

Confused Member
Subscriber
I noticed many members have moved on to a SUT, does it replace your phono preamp? is it added to your preamp??
what is a SUT? do you build one or buy one?
 
In very simple terms (I've just been looking into these myself) its a way to passively increase the output from your moving coil cart to allow the output to be plugged into an amplifier's MM phono input.

MC carts have lower output than MM, and need 30dB boost or so to be heard. Another complication is that MC carts have a range of outputs. I have a Denon DL-103, which is a LOMC (low output MC).

You can go passive with a SUT - or active with a "pre-pre amp" that does the same job - however actively.

A SUT is meant to be the best way - however many of them are expensive. There are some cheaper ones - or you can make your own by using appropriate transformers pulled from microphones.

I've just bought a Boozehound FET active pre-pre amp - which does the same thing as a SUT, however many would argue, with probably less quality. I like it though for my setup anyway.
 
A step up transformer is a sut, they amplify the output to the mm phono pre amp basically, and the sound is supposed to be more natural sounding. I have 4 suts on my tables and prefer the sound more than just going direct to an mc input . I feel it's an overall better sound stage , is wider, deeper, and quieter. Better break up of instruments as well. You can get custom built ones from 100 and up. Name brand built are typically more expensive but I have found the custom to be a better product and overall cheaper to get.
 
I noticed many members have moved on to a SUT, does it replace your phono preamp? is it added to your preamp??
what is a SUT? do you build one or buy one?

The cartridge out put is a major factor in choosing the SUT .

For example the Ortofon Rondo Red that you posted in another threat has an Output voltage at 1000 Hz, 5cm/sec. 0.5 mV .

The same put put all the way up to and including the Ortofon Rondo Bronze.

For that series, you will only need a basic SUT.

Check this one out, an old work horse from years gone by:
Vintage Ortofon STM 72 MC Step Up Transformer :thumbsup:
 
Last edited:
So is there any benefit in running an SUT into a flexible stand-alone MM/MC phonostage, or is it more applicable to run into an integrated or receiver that has only an MM stage and/or a "fixed" MC stage?
 
The long version, probably more complete, to answer your questions.

http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html

Straight from the keyboard of an AK sponsor.

The STM-72 linked is a very high output unit designed for a VLOMC, the MC-20 with an output of 0.07mV or 70microVolts. It would not be my choice. Sold the one I have even though I have an MC-20.

You can benefit from an SUT into the MM section of an MC/MM capable phono pre if the SUT sounds better than the MC amp in the phono pre. There were choices back then but both were to plug into a phono input, SUT or a moving coil phono pre-preamp. Both provided some gain but no eq to get into a phono input designed for MM cartridges. Today we have phono pres for MM and or MC, SUTs, and MC phono pre-preamps. I have one of each. Finding vinyl nirvana is a long journey, just look at all the work Mister Pig is doing and he has better funding for his phono rig than many here.
 
So is there any benefit in running an SUT into a flexible stand-alone MM/MC phonostage, or is it more applicable to run into an integrated or receiver that has only an MM stage and/or a "fixed" MC stage?

Price and performance is going to be the limiting factor.

For example some " high end " lomc have only Output voltage: 0.15mV.

The SUT that can handle that kind of boost and stay quiet is going to be a very good performer and also " expensive" - at least to me.

Don't know which particular stand alone phono stage would be able to boost that and how much it would cost. :dunno:
 
The cartridge out put is a major factor in choosing the SUT .

For example the Ortofon Rondo Red that you posted in another threat has an Output voltage at 1000 Hz, 5cm/sec. 0.5 mV .

The same put put all the way up to and including the Ortofon Rondo Bronze.

For that series, you will only need a basic SUT.

Check this one out, an old work horse from years gone by:
Vintage Ortofon STM 72 MC Step Up Transformer :thumbsup:


I am going to use a Ortofon Rondo Red, but this seems complicated. I was also going to use a Denon DL103R
 
The cartridge out put is a major factor in choosing the SUT .

I am going to use a Ortofon Rondo Red, but this seems complicated. I was also going to use a Denon DL103R

You will only need a SUT capable of boosting 0.5 mV.

And this is why I use a adjustable Phono Head Amp as when you want to switch cartridges, you have the option to change gain and loading without buying another unit.
 
The OP's basic question has been answered already so I won't repeat that information. However, I will mention that the vast majority of modern mc cartridges have quite healthy output voltages around 0.3mV - 0.6mV and a SUT with a turns ratio of 1:10 will handle them nicely. 1:20 might be better for the cartridges at the low end of that range.
There used to be a lot more mc cartridges with much lower outputs, for example some of Ortofon's cartridges from the 1980s were as low as 0.025mV - about 1/20th of what is typical today. Those cartridges required SUTs with a much higher turns ratio than 1:10 and the Ortofon STM-72 was a high ratio SUT designed for the job. I think its turns ratio
was 1:60, which makes it fine for those very low output cartridges but less than ideal for a typical modern mc cartridge.

BTW, a modern mc phonostage will work well enough with a modern mc cartridge (with an output of about 0.3mV or above) but will struggle to give enough gain and a low-noise performance with one of those vintage Ortofons with an extremely low output voltage.
 
Back
Top Bottom