SUT - electrical theory and practical experience

I can only speak a little to the theory.  A step up transformer works on the same principle of voltage transformation used for AC power products.  For instance, when you buy gear designed for US voltages but want to use it in Japan.  Transformers can convert one voltage to another, but the power on either side of the transformer is roughly the same (minus losses). 

That is, a 100V to 120V transformer will still have the same power (current x voltage) on either side, 

Like Eric says, a transformer is a device that transforms the voltage to current ratio of a power source, in either direction, where Power, which is a product of voltage times current, is a constant. So when V goes up, current (I) must go down in direct proportion to the increase in V, and vice-versa. While that happens, there is also an effect on impedance, from one side to the other of a transformer. In a SUT, the output V of a cartridge is increased in direct relation to the turns ratio of the SUT (as in all other transformers). For example, a 1:10 SUT will increase cartridge output V by 10-fold. Meantime, the current output of the cartridge is likewise reduced by 10-fold. The effect on impedance, on the other hand, is related to the square of the turns ratio. So, for a 1:10 SUT, the impedance "seen" by the cartridge on the primary side of the transformer will be reduced by 100-fold in relation to the input impedance of the phono stage. A 47K phono load resistor on a typical MM phono stage will look like 470 ohms to the MC cartridge. As to the rest of it, that is the subject of eternal debate among audiophiles, and I won’t go there.

As tiny as the signal is from a MC cartridge, it is a, relatively speaking, high current/low voltage source.  The phono amplifier is designed as a voltage amplifier.  The step up transformer converts high current/low voltage to high voltage/low current, which means that the amplifier has more voltage to work with and amplify.  As the name suggests, it transforms current to voltage so it is not actually amplifying the signal--there is no need for an additional source of power and active devices to amplify the signal.  

Is it better to employ active amplification instead of current to voltage transformation as the first stage?  Opinions obviously vary on this.  Some people eschew use of transformers while others prefer it over an additional stage of active amplification.  With a lot of tube phono stages, the use of a transformer for the first stage is preferred because active tube amplification is somewhat noisy, and eliminating the first stage by using the "free" conversion of a transformer means less noise.  I suspect that some people, myself included, like the sound of transformers (i.e., euphonic coloration).  

"euphonic coloration".  Which is to say you believe SUTs introduce a coloration.  Which is one subject of that eternal debate I mentioned.

I personally have never owned a SUT.

Perhaps they do, I don't care about religious arguments over purity or neutrality, etc. because I like many tube phono stages that employ a SUT.  My own, a Viva Fono has a built in SUT.  The Audio Note phonostages are all MM stages with the expectation that an SUT will be used ahead of he stage (they sell some very pricey SUT for that purpose).  Zanden's phono stages employ Jensen SUT.  

SUT's clearly can work. And an argument can be made against them. 

For those designing 'minimalist' vacuum tube stages they are 'free gain'

For others they are a bandwidth limiter. But this could be a good thing depending on your school of thought.  

SUTs are about gain. You can increase gain via a transformer or a circuit. As with most things audio some methods sound better and have other advantages than others 

All these things can be covered by a good phono pre-amp with adjustments for such things.

I can only talk a little to the practice. An excellent SUT represents a real improvement over most transformers present in phono stages. 

Which is to say a good SUT is preferable to a mediocre SUT, on the assumption that built in SUTs are mediocre. But what about Allnic and a few others with very high quality built in SUTs? The advantages there include fewer connectors and ICs.

I can only speak a little to the theory.  A step up transformer works on the same principle of voltage transformation used for AC power products.  For instance, when you buy gear designed for US voltages but want to use it in Japan.  Transformers can convert one voltage to another, but the power on either side of the transformer is roughly the same (minus losses). 

That is, a 100V to 120V transformer will still have the same power (current x voltage) on either side, 

That is also how I generally thing of them as well @erik_squires - but they are also a current converter to some extent… and the current coming in gets changed inversely proportional to the voltage change.

And… also they (SUTs) work on magnetic fields so they are a current device.

@drbond Maybe think of a 10:1 transformer as increasing the winding on the cartridge by 10x?
Just not making the cartridge’s motor 10x heavier.

I am still a bit uneasy as the cartridge is more of a current generating motor than a voltage generator.

Pretty sure one cannot be a fan of Sutherland, and other trans impedance phono stages… and simultaneously a fan SUTs. Maybe it is possible.

Holmz, please read my long post and Larry’s too, near the top of this thread. Of course transformers transform both voltage and current in direct proportion. The product of volts X current on the primary equals the product of volts X current on the secondaries. Don’t make the subject harder or more vague than it needs to be.

Dave Slagle is well a known and respected manufacture of custom SUTs and does an excellent description of the theory and details - intact audio.  Beyond that he winds with both copper and silver, and each will have a different perspective to the music.  There are variations in core material that can influence the sound with each SUT manufacturer often favoring one over another.  

My own experience has been quite positive moving from a solid-state phono-preamp to a Tron Seven Reference with SUT and tubes and was quite surprised on the overall improvement, much more than incremental - equally quiet with better bass and overall extension and soundstage.  But the devil is in the details, and results can vary.

@lewm your post gave me pause, and I reviewed Maxwell and Faraday… and I see that the voltage and current are indeed related in Maxwell’s equations.

antinn,

A friend has the Tron and it is indeed a good pono stage.  You can tailor the sound to your specific system and taste by trying different tubes.  This is a component worth going that extra mile to optimize.

As to the issue of built in or separate SUT, I have mixed feelings.  A built in SUT of good quality will save one the expense and trouble with finding the right interconnect.  Also, outboard SUT tend to be more prone to picking up noise and hum from external electrical fields.  On the other hand, one can, with separate SUTs, one can find the best match for your choice of cartridge and one can move the SUT around to minimize hum and other noise issues, whereas, if the built in SUT is the source of such noise, one cannot change its location and orientation.  As to the optimizing of the choice of SUT.  I agree with what Art Dudley said many years ago.  He noted that even when a particular SUT supposedly has non-optimal gain or other characteristics for a particular cartridge, he noted that they usually still sound very good.  He said that he never found a SUT that he didn't like.

SUTs are all about the quality of the transformers. I run a Bob‘s Devices Altec Lansing TBB103 and can confirm that using the gain stage of my Zyx Artisan instead leads to a major deterioration from my Zyx Universe. 

I ask this question strictly for my own education and interest in this thread from a science point of view.  I have no opinion.  Having taken college level physics I understand the principal, windings,  etc.  As far as audio SQ  though, would it be safe to say that it should be a perfect conversion as long as they dont have frequency/phase dependent properties?  Is there a physics reason to think they are dispersive?  If they can be, then the materials, construction, etc matter.  Then we run down that rabbit hole and in this case yes, they affect SQ unless built in the best possible manner.  In any case it would need to be shielded from EM as that induces a stray current ie noise (actually how they work really).  

not sure you clearly understand the need to use a SUT.

Moving Coil cartridges are different technology than Moving Magnet. MC, the small lightweight coil moves (rather than the heavy magnet moving). Allowing a refined and more accurate signal fidelity (or so most believe to be true).

Lightweight moving coil makes a weaker signal strength. That low signal needs to be MAGNIFIED (not enhanced), just boosted in strength enough to be essentially as strong as a MM cartridge’s strength.

At MM strength, the/any phono signal needs to be ’equalized’ by the industry standard RIAA curve. That is what a ’PHONO STAGE’ does. Phono stage can be a dedicated phono input in a preamp or built into a separate Phono Stage.

Once ’equalized’, it is equal to any LINE level input, i.e. AUX, line 1,2,3 ...

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SUTs, MC cartridge (step up transformers), need no power, their internal transformers have alternate windings that modify/boost (but not enhance) the signal strength simply by the specific design of the transformer.

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Voltage Transformers are very different. i.e. My Japanese Turntable is designed to run on Japanese standard voltage of 100 volts. I need a STEP DOWN transformer, that converts my USA 110/120 volt down to 100 volts, and I plug my 100 volt TT into it. Those are powered devices.

Step Down transformers exist also. They alter Voltage.

To answer the OP's question re: what does the SUT do to the sound quality...

For what it's worth,I have several phono stages and several active step up devices/ SUTs and generally, the SUTs are quieter and more open (when properly matched etc...)

I currently run a Sunvalley Audio SV-EQ1616D phono stage and ZYX cartridge. The Sunvalley has a built in " FET head amplifier that adds another 25–32dB gain with fixed 50 ohm loading for use with low-output moving-coil cartridges". The MM stage is good, the FET is NO Match for a good SUT. (n.b. the proper load for the cart is +100 ohm). I am using a copper wound SUT in custom housing and sheilding. Best combo I've had since the 70's.

Elliot, in operating principle there is absolutely no difference between your step down transformer and a SUT. The functional difference is only in the respective turns ratios, and also the fact that a SUT has to handle a wide bandwidth whereas the step down always works at one fixed frequency.

lewm

I wanted OP to understand:

cartridge SUTs are PASSIVE, no need to plug them in. And that they boost signal strength by themselves, i.e. boost, not ’enhance’ the signal.

Step Up or Step Down NEED to be plugged in to wall outlets. They also boost/cut voltages and do not enhance signals.

And a Cartridge SUT is working on a phono cartridge signal that goes into the preamp/amp/speaker system

A Step Up/ Down Voltage converter has nothing to do with the audio signal, just proper voltage to the motor.

Of course to alter AC line voltage a step down transformer of the kind you own must be inserted into the AC line. That’s precisely analogous to inserting a SUT between a cartridge and an MM phono stage in order for it to do its work. Both are passive devices. You implied that your step down is per se dependent on AC for power. I hope the difference is clear.

Dear @drbond  : " Does the SUT theoretically enhance or degrade the sound quality?  What does the SUT actually do to the sound quality?  "

First any device where the signal must pass degrades the sound quality, so the SUT degrades the signal quality and there is no way no matters what that that SUT could enhance the audio signal.

Today SUT's exist because there are tubes phono stages and even that exist 2-3 all tube high gain active units those are not the best solution for LOMC cartridges.

A SUT is not a passive device because any audio signal passing trhough those transformers makes that the " hundreds " of meters on each transformer react to that signal and starts the degradation and you have to think that the signal has a " long trip " inside each transformer wires and at each mm. the audio signal is degrading by that SUT. 

In the other side a good SS active high gain design say ith bipolar  active devices the signal must pass only trhough a matched pair of transistors in that first critical gain stage and degradation is at minimum way lower that in a SUT.

Advantage of a SUT: NONE. SUT develops or could be contaminated with some kind of " noise/colorations " and yes its frequency response is way limited and not only that: everything the same the badwindth, noise levels, THD, deeper bass, etc, etc belongs to the SS active high gain.

You can ask for measured frequency response and the like to any today builder to confim all what I mentioned.

I owned and still own SUTs and the only one that I listen time to time is the Denon 

AU-1000 modified by me where that SUT only sees a connector when in the MM phono stage. This Denon measured FR is: 5hz to 200khz, that's exceptional for any SUT and I admit that my modified unit puts the level degradation ower that any other SUT I experienced but not even my SS Essential 3180 phonolinepreamp.

There are several SS active high gain phono stages and normally are expensive ones as FM Acoustics or CH or the Channel D Seta L20 but exist very low price as 2.5K only SS units that makes a formidable job. Here one of those unit reviewed by MF and compared against Dartzeel and other way $$$$$ phono stages:

Today top LOMC cartridges are really expensive and makes no sense at at all try to been mated with a SUT that as I said and no matter what will degrades that valuable cartridge signal.

For me that I'm a MUSIC lover the only  path is a SS active high gain phono stage but only an opinion.

Regards and enjoy the MUSIC,

R.

Raul, By "passive", I only mean that it does not require or consume external power.  OK?  You can use any other definition you want.

I’m a SUT + LOMC fan. I just like the sound many (most?) SUT’s provide - rich, meaty, weighty. In my system, that’s the right direction - other systems may differ. I have an Audio Research Reference 3SE with a really great JFET MC stage. In the past I’ve had a Herron VTPH-2A, also with a great JFET MC stage. These JFET stages sound great, BUT they’re inevitably leaner and more sterile sounding than the SUTs I like. I have about a dozen MCs, so my listening experience is not limited to 1 or 2 models.

That said, there’s a pretty great variance in the sonics of different SUT brands. The difference can be as significant as changing cartridge brands, even when the step-up ratio is kept close. It’s quite striking. The blue-label CineMags (this includes Bob’s Devices Sky, 1131, 1254) are very much on the rich/lush/weighty side of things. The EAR has a particularly romantic tube-like midrange. The Quadratic MC-1 (a CineMag blue but with a MUCH bigger core than usual) has extremely low distortion through the midrange and treble with extremely powerful bass response. The Hashimoto and Koetsu are also excellent, and a bit more neutral, though still with more weight than a JFET. The Lundahl LL1931 and LL1931Ag (amorphous core) is much thinner and more "crystalline" sounding - not a bad sounding SUT, but not my personal preference! I think I actually prefer the JFET stages to these. Also - don’t skimp with a cheap SUT; I found the Red-label CineMag 3440A (cheaper than and blue-label) to be borderline bad, and the Lundhal LL9206 (cheaper than LL1931) to be fairly mediocre.

One practical consideration is you really need a very short, low capacitance run of cable from SUT to phono stage. If not, you’re going to REALLY hear this cable, in a bad way. And a 20x step-up ratio is usually a "pretty good" choice for many/most LOMC cartridges.

I’ve found a good SUT will be quieter than a good JFET stage IF (!!) you can properly address all grounding gremlins.

"One practical consideration is you really need a very short, low capacitance run of cable from SUT to phono stage."  Which is a good reason for having a high quality SUT built in to the phono circuit, on board.

Dear @mulveling : " I’ve found a good SUT will be quieter than a good JFET stage "

Only true reason for that is that your JFET unit is a mediocre overall design.

Btw, "" rich, meaty, weighty. ""

typical " audiophile/tube " adjectives that means nothing about MUSIC, specially live MUSIC seated at near field position that’s where the recording microphones are positioned. Your statement means that you like sound full of developed COLORATIONS/DISTORTIONS.

R.

R.

"One practical consideration is you really need a very short, low capacitance run of cable from SUT to phono stage." Which is a good reason for having a high quality SUT built in to the phono circuit, on board.

@lewm - That’s somewhat true. It’s an advantage to be onboard in the phono stage box. However, I have LL1931 built into my VAC Renaissance SE (another phono stage I own) and my preference for different SUTs greatly overrides the advantages of being onboard. I also have an outboard K&K SUT box with LL1931Ag (i.e. I’ve tried LL1931 both onboard and outboard), so I know it’s really the LL1931 sound that I don’t like.

Being onboard reduces the chances you’ll have a grounding hum issue. And of course it eliminates the chore of picking a transparent IC. But once you know you need a low capacitance short run IC, it’s pretty easy to find a "transparent enough" cable.

For me, the ability to choose a SUT to my preference is by far the dominant factor over issues with IC’s or grounding. I’ve yet to be super-impressed with an onboard SUT.

Your statement means that you like sound full of developed COLORATIONS/DISTORTIONS.

@rauliruegas  - and I'm OK with that 😁
I'm definitely not trying to pose as someone in pursuit of the "ultimate truth" in sound. I go for what pleases me the most. 

Good for you, no problem.

R.

An interesting discussion for sure.  I have to laugh concerning the argument that transformers insert distortions, whereas active circuits using transitors somehow do not.  We are talking about playing vinyl records people.  Everything has distortion.  If we really want to reduce "colorations/distortionns" to the maximum extent possible, we should all pull up stakes and move over to the digital realm completely.  I must reinforce the points made by mulveling as my experiences are very similar.  I have a Conrad-Johnson TEA1-series 3 with built in SUT and although it is very good, it is not as good as any of several external SUTs that I own.  I have a couple of different active phono stages that probably have lower distortion than even my best SUTs, but they don't satisfy my ear as well as the best of the transformers, which is a hideously expensive one made in Germany wound with silver wire.   I have a Bob's Devices one that sounds lush and warm, overly so for me.

My advice to anyone starting out?  Try them out, find what you like.  Satisfy your own self.  In spite of the admonitions to the contrary, the only truth in analog is your own taste.

Dear @billstevenson  :  Please don't laugh and read again ( if you are refering to my post. ).

"" First any device where the signal must pass degrades the sound quality, "

"pass only trhough a matched pair of transistors in that first critical gain stage and degradation is at minimum way lower that in a SUT"

R.

R,

If you are sincere, I commend DSD to your attention.  Otherwise, I think you are on a quest that is analogous to slaying windmills.

I will stand by my advice to make yourself happy, play what pleases your ears and when it comes to analog, especially analog, recognize that it is perfectly OK to prefer tubes and SUTs.  It is perfectly ok to prefer a matched pair of transistors too.  The only thing that matters is the music.

Bill

I’m not sure that I completely understand the matter, but it seems that there are two options in cartridge signal amplification in or before the phono stage: either 1. an SUT before the phono stage, or 2. a transistor in the phono stage.

If that’s the case, then the sound quality would depend on how linear the electric signal is transmitted by either the SUT or the transistor. Then, I suppose both approaches have certain weaknesses, but under near ideal circumstances, both would sound nearly identical.

Are there any inherent weaknesses in a SUT versus a transistor, or vice versa?

I’m not sure that I completely understand the matter, but it seems that there are two options in cartridge signal amplification in or before the phono stage: either 1. an SUT before the phono stage, or 2. a transistor in the phono stage.

either ~40dB of active gain and ~20dB of SUT, or more active gain to get to around 60dB… which is 50-70dB.

If that’s the case, then the sound quality would depend on how linear the electric signal is transmitted by either the SUT or the transistor.

That assumes that linear is good.
The active circuit might give more schott noise as hiss, and have lower distortion.
And the SUT may have higher distortion.
But that assumes that distortion is bad and unwanted.

Then, I suppose both approaches have certain weaknesses, but under near ideal circumstances, both would sound nearly identical.

yeah in the limit they would.

Are there any inherent weaknesses in a SUT versus a transistor, or vice versa?

One can do an opening roll of a 7 or 11 and win at the craps table.

"Are there any inherent weaknesses in a SUT versus a transistor, or vice versa?"

If I didn't know you were serious, I would suspect you of being a troll based on this sentence.  The question has already been broached here in this thread.  Elsewhere on the Audiogon Analog website and on every other audio-oriented website I have ever visited, the question is hotly debated with much expenditure of wind.  In the end, you have to make up your own mind, usually by listening.

@billstevenson 

I definitely share your philosophy! It's analog. It's meant to be beautiful, not "perfect".

SUTs are tricky and they do have advantages.

The tricky bit is they have to be loaded correctly. Many SUTs are meant to be used with a specific cartridge; such SUTs as a result are meant to be loaded at their output by the 47K input impedance of the phono section (47K is the standard for phono input sections).

If the loading is different, for example the load is a higher impedance, the transformer can 'ring' (distort) and so will sound brighter. This can also happen if a different cartidge, with a difference source impedance is used. Transformers are call that because they transform impedance and this goes both ways: I can't be more emphatic that transformers do not isolate impedance!

Jensen Transformers makes very high quality SUTs and have several models, some meant to be used with tubes and others with solid state. Because they have a generic quality, to deal with the loading problem Jensen has published a chart that shows what resistor/capacitor combination should be at its output so as to prevent ringing.

The advantage of SUTs are several. First, they contribute almost no Johnson noise at all (which would be heard as hiss otherwise) and so can benefit both tube and solid state phono sections if a LOMC cartridge is being used. This is the most obvious benefit.

The next benefit is that SUTs, being transformers, allow you to run the input and/or output balanced or single-ended. In this manner you can minimize the sonic artifact that is caused by the tonearm cable; so those of you that spent a lot of money on the tonearm cable take note: if you also run an SUT you can go balanced from the phono cartridge (which is a balanced source) and so get better performance from the cable, which is arguably the most important place in the audio system that the cable really be right. Any place further downstream will not be able to make up for any deficiencies or colorations imposed by the cable! You can do this even if your phono section has a single-ended input.

Finally, SUTs usually do not have bandwidth much past 100KHz. For this reason, they can effectively block the RFI that is usually caused by the cartridge inductance being in parallel with the capacitance of the tonearm cable. People that don't use SUTs often resort to 'cartridge loading' resistors to get rid of the distortion caused by this problem, although they usually think they are tuning out brightness. What they don't realize is that the brightness is the result of distortion. Take away the RFI and the overload it causes to the phono section and the brightness is gone.

I've written plenty about the adverse effects 'cartridge loading' can cause and will not repeat myself here.

For those that don't use an SUT though, the RFI generated must be dealt with; its my theory that the reason there is an SUT vs direct in debate (for those of you who have preamps that have sufficient gain) has to do with whether the RFI is dealt with properly when running direct-in.

IME, most designers of phono sections do not take the phenomena of the electrical resonance/RFI problem of LOMC cartridges into account in their designs, so the design has problems with high frequency overload as result. But if that problem is dealt with, usually a phono section that can run direct-in will sound more transparent than using an SUT. This is simply because there won't be additional distortion.

In a nutshell what I'm saying is if you need the gain because your phono section only does high output cartridges, this is a good way to go. It might sound better than a poorly designed high gain phono section as well. But if the phono section is properly designed it goes the other way!

Ultimately the designer/dealer or whatever likely isn't going to tell you what's up with all this; IME if they don't know about the cartridge electrical resonance issue you'll get snowed. So you just have to try it and see what works.

And in case its not obvious, keep the interconnect cable capacitance as low as possible. This means don't use regular interconnects not meant for use with a phono cartridge!

My Johnson is very quiet without a SUT, speaking for myself only.

But seriously folks, Ralph (Atma-sphere), you have often mentioned the notion that high gain phono input stages need to be designed to be insensitive to RFI.  What design elements contribute to that good behavior?  Is it simply a matter of limiting the bandwidth?

@atmasphere 

That's a very thorough, well-considered assessment of the advantages and disadvantages of SUT.  Thanks for taking the time to share your knowledge with me / us!  

you have often mentioned the notion that high gain phono input stages need to be designed to be insensitive to RFI.  What design elements contribute to that good behavior?  Is it simply a matter of limiting the bandwidth?

@lewm I wouldn't say its any one thing. I've found that bandwidth (on the RIAA curve) is a good idea up to about 100KHz (I have an anecdote about that which taught me the importance of this).

Beyond 100KHz you get into RFI issues from the cartridge. That might not be a problem if the phono section input can handle the RFI without overloading. This is much easier to do with tubes than it is with solid state! If using solid state at that point I would say yes, bandwidth limiting is a good thing. You would have to be careful that any RF energy can't get rectified by a non-linear problem though! So to deal with this problem you'll be using several techniques to sort it out.

I mentioned that this is easier to do with tubes; the reason is that if solid state there is often a feedback loop involved. Its possible for the portion of the circuit that is causing the problem to be outside the feedback loop. The reason for that can be subtle; for example you'd think an opamp using feedback would be immune to this problem since the feedback is applied outside of the opamp. But if the opamp lacks the bandwidth, you can have a situation where the RFI comes in but isn't corrected because its outside of the passband of the opamp. So it distorts. The trick there is likely to not ask so much gain of the opamp but you have to be aware of the RFI problem in order to get that far...

Dear @drbond : In april of this year you started a more or less similar tread where all was explained about SUT and the like but obviously as in this thread too you have not a 100% understand of the whole subject.

Now, you decided to buy the CH phono stage with the " additional " power supply so what’s all about SUTs? Maybe you need tomatch the CH to a different amp. You diminished the JC 1+ maybe by its very low price, you will be surprised if you listen to it in the same way that Fremer/Atkinson were with the humble Stellar SS phono stage.

Could you explain a little? maybe you are thinking to change your CH fora SUT road?. I don’t know something makes no sense down there. You own the Lyra Atlas why not ask J.Carr if he prefers a SUT or an active high gain S phono stage?

""

but under near ideal circumstances, both would sound nearly identical.

Are there any inherent weaknesses in a SUT versus a transistor, or vice versa? ""

In your other thread and in this thread me and other gentlemans let very clear the differences with an additional disadvantage with SUT due that you need additional connectors and cables for that external SUT. You need to use your common sense too.

An about all that theory of the RFI is only that and happened 20-30 years ago but that mediocrity SS designs almost disappeared and I say " almost " because always are bad designs. Today designers learned. Bandwindth? your CH has an over 500 khz of bandwidth and the Channel D over 2 Mhz, Spectral over 1.5 Mhz , my Essential 3180 over 1.5 Mhz with no trouble at all.

Please read the M.Fremer Stellar 2,5K active high gain SS phono stage and additional read its measurements where J.Atkinson really was surprised by it RIAA accuracy that at least even the CH one and not only that but its very low noise levels and its incredible overload marginn at 30dbs in low gain and almost 20dbs in high gain position and you have all those for only 2.5K and makes MUSIC comparable to the Dartzeel that set you back 20 times over the Stellar price tag. Fremer listened using the SAT tonearm in continnum TT and the Ortofon Ana Diamond. Can you look in that review any SUT? why not?

COMMON SENSE, it does not need it due to its higher signal degradation.

R.

@rauliruegas 

I think a course in English comprehension would benefit you immensely, and allow you to contribute more positively to these forum discussions:

Firstly, the thread in April was a thread about phono stages for a particular turntable, and only peripherally and incidentally touched on SUT's, and did not go into the theory or discussion of what SUT's do to audio signal / SQ in any detail. 

Secondly, you hijacked that April thread on phono stages and ceaselessly posted about power amplifiers, which I surmise is due to your inability to comprehend what is written in English.  

Thirdly, I am still enjoying the CH Precision P1 with X1 power supply, and have no intention of changing that component, but I am intellectually curious about other approaches to phono signal, and why one approach is chosen over another, and @atmasphere was kind enough to share a very thorough explanation yesterday.  

In the future, I may get an SUT to use to plug into the MM input of the CH Precision P1, just to compare the SQ from the MC current input and the MC voltage input, or perhaps I'll get a second phono stage to compare SQ with.  This is just a fun hobby for me.   

Btw, seven months ago I told you yhat you have a " problem " with your 90K monobloks and your " passive " line preamp. Even I gave you the whole Atkinson explanation on your amps and why he just did not recomended it and Atkinson is a trusty and unbiased reviewer that for years owned tube/sut electronics and analog but after around 10 years latter he switched to SS and no SUT electronics and for very good reasons , latter on he switched to digital alternative and no more analog but he is not only an audio unit reviewer but a recording engennering too and for the last 20+ years he made and makes audio devices measurements with very good tools for that in deep job and he always explains those measurements and wht means. You need to read again my 7 months ago post.

I remember you was looking for a phono stage in the 50k-70k price tag my advise was for: Dartzeel, Boulder, FMA, SimsAudio and some one gave you the advise for CH and you decided for CH.

For me is clear that you are not " satisfied " with what you are listened and you are thinking that a SUT can " enhance " your experienc but no SUT or other similar device can enhance nothing but the other way aroun: can degrade the audio signal including SS units the important issue is which device makes the minimum audio signal degradation everything the same and certainly SUT is not that device.

Btw, if " passive " units as your line preamp be in true better alternative then 90% of electronics been " passive " but things are that things are the other way around.

In the other side when a designer decides to use a SUT instead of an active high gain stages it’s not because SUT is better ( because it’s not in true. ) but because that designer has not the knowledge adequated levels and skills to design with out SUT and not for other reason.

Here a second Stellar review that confirms its " stellar " quality levels and confirms Atkinson measurements and in the picture you can see a really audio signal short path and the SMD full parts evrywhere, it’s not at random that the Stellar performs with that very high quality levels and as I told you with no SUT:

Btw, what atmasphere posted was theory that today it just does not happens and all that that you can use balance cable connectuion to the phono stage because th SUT is bs becase I think is what you do with your balnced CH unit.

Try to that some one browse you ( even if you pay for it ) the JC 1+ and a non-passive line preamp. Which the problem with? if you don't like then you confirm that what you own is the rigth road to go but if not then you could learn " something " about to fine tunning your room/system.I think that you need a different line preamp and amps and that’s it.

R. Sorry, when I was writing this post you just posted yours. So, forgeret my post.

Maybe I'm a little " stupid " and don't understand your way of thinking or what you are looking at and I said that because you are thinking to in the time add a SUT to the CH and what do you need to add that SUT?:

well obviuosly the SUT and an IC cable and what does that means?

that the valuable and way sensitive cartridge audio signal not muts pass through a pair of additional SUT input connectors that degrades that signal as does too the solder joints and from there the audio signal will continue hislong tortuose path through the " hundreds " meters of transformers wires that react to the cartridge signal and that follows the degradatio  but this is not the end because the signal now must pass for other pairs of SUT output connectors and solder joints along the IC cables. Why all those long totuose path against your today DIRECT cartridge audio signal path? Makes sense to you? if yes, then  go a head. No problem with me.

@rauliruegas

With your extensive experience and knowledge, I think you really could contribute positively to these audiogon threads, but somehow, I think you just do not comprehend the details of what is being discussed. No, I never said, nor is there a "problem" with the Ypsilon monoblocks, and so far I’ve yet to hear anything that is as transparent, delicate, and detailed, with proper timbre as the passive Ypsilon pre-amplifier. . . but let’s not hijack another thread into another topic, as this is just for SUT discussion.

Now discussion of how signal is actually transmitted through a SUT would be quite interesting: does the signal actually move through the wound wire? As we know, the electrons in a wire don’t travel. . . do you think that the signal is rather transmitted via the core, and not the wires? What really happens to the signal? I don’t know if anyone really knows (but I’m not an electrical engineer), but I do know the limitations of human knowledge. Now, how much of the signal is purely electrical, and how much is magnetic, and can they even be separated? I suppose now it gets into a "religious" argument, where our minds may not be able to comprehend the exact way that everything works.

I hope you enjoy your weekend!

Now discussion of how signal is actually transmitted through a SUT would be quite interesting: does the signal actually move through the wound wire? As we know, the electrons in a wire don’t travel. . . do you think that the signal is rather transmitted via the core, and not the wires? What really happens to the signal? I don’t know if anyone really knows (but I’m not an electrical engineer), but I do know the limitations of human knowledge. Now, how much of the signal is purely electrical, and how much is magnetic, and can they even be separated? I suppose now it gets into a "religious" argument, where our minds may not be able to comprehend the exact way that everything works.

The coil(s) in the cartridge outputs a current based upon maxwells equation description of a magnetic field moving across a coil.
So it is an electric field that is pushing the electrons along in a back-n-forth AC fashion.

In the SUT, the current creates a magnetic field from the input winding of the coil, and the output winding creates a voltage and current to fight (or in response to) the magnetic field.

And yes… the electric field pushes those electrons along, which in an AC field result in no net significant movement on the average over time.

 Now, how much of the signal is purely electrical, and how much is magnetic, and can they even be separated?

A cartridge, SUT and speaker driver, all have a significant magnetic field component to their design.

I suppose now it gets into a "religious" argument, where our minds may not be able to comprehend the exact way that everything works.

Maxwell’s equations are at the core of “the religion” of what is happening. EEs are generally the ones that comprehend this to provide the designs to manifest “the religion” into reality.

Drbond, transformer theory is a deep subject. The only person with deep knowledge who ever posts on Audiogon is Dave Slagle (Intact Audio). Otherwise you are not going to find enlightened discussion here. I suggest you do an internet search. The subject interests me as well. For example, some who dislike SUTs like to lament the concept that the signal is actually traveling along the many yards of fine wire that make up the primary winding thereby suffering degradation even befor being transformed. But I think there is some basis for treating the primary winding as a singular entity. Dave could speak more eloquently on this but also you might find such a discussion on line.

Dear @holmz  : As always thank's for your post:

R.