Phono Preamp. With transformer or fully active

What is the difference in sound between a fully active phono stage and one that uses a transformer for part of gain 

I read  discussions in External SUT’s being used and phono stages with built in transformers ?

I noticed that CJ Tea2 has two inputs one is with transformer & one is fully active ?

l also read discussions on fully active 
What is better?   Lol

is the sound softer, more detail , more soundstaging? Quieter?

With one SUT you can't use all MC cartridges, such phono stage is not universal for all MC. It will work for some of them nicely, but if your cartridge impedance is very low (2 Ohm) or very high (40 Ohm) you can't use one SUT for both of them. 

Active phono stage with optional gain and optional loading is universal, one phono stage for all MC cartridges. 

SUTs are as diverse in their sound as phono stages are (maybe even more so), so it’s difficult to put all the stages with built-in SUTs into a bucket. And as mentioned by chakster, any given SUT is not nearly as adaptable to a wide range of cartridges as a typical active MC stage would be - so when picking a SUT you generally also have to select either a single target cartridge, or a narrow window of target cartridges for best results. It’s not going to work great if you have a low output MC, medium MC, and high MC in your collection. It’s not going to work great if you have a cartridge with high coil impedance for its output level, like a Benz Ruby. You must keep that in mind when choosing a phono stage with a SUT MC stage. Of course you can always do what I do - bypass the stage’s internal SUT and use outboard SUTs of your choice coupled to its MM mode.

SUTs are generally paired with tube MM stages to keep the tube rush noise down. Kind of the "best of both worlds" approach. But there’s no reason they can’t also work great with SS MM stages - it just seems less common probably for market factors more than anything else.

In my experience, two ends of the SUT sonic spectrum would be Bob’s Devices blue label CineMags with a warm, meaty, fleshy and seductive sound - and then Lundahl LL1931 amorphous cores with a crystalline, fast, detailed sound. Both of these have found their way into many phono stages. Personally I’ve found the CineMags to work better for me so far.

I chose my VAC Renaissance phono stage because its tube MM stage was by far the best I’ve heard, even though it uses Lundahl SUTs for MC mode. I just bypass them to favor my various outboard SUTs :)

As for transformer SUT vs. active MC stage (JFET), I have definitely preferred the sound of SUT so far. It’s generally more tactile, more dynamic, more alive sounding. JFET sounds more like a reproduction to me; I feel emotionally more distant to the music (slightly). But at this point I’ve heard only a few JFET stages and have a lot more experience with SUTs.

And one annoying thing with SUTs (especially outboard) is tracking down various hum / grounding issues. At least with built-in SUTs they usually get that right for you.
For DIYers, Jensen SUTs are also excellent, and Jensen offer technical advice on how to implement them, as do EMIA.  Bob's Devices, Lundahl, Jensen, EMIA, are only a very partial list of good companies that make SUTs. Having said that, I don't own a SUT; I do own 3 high gain phono stages that can accommodate a range of MC cartridges.
All these problems and limitations are out there and known, and that is why I have made the decision to not mess with them. Yes even knowing this means passing up the chance at discovering audio nirvana. The magic combination. Hats off to those who have. Me, I think just getting a record to play back properly is hard enough, without making it even more complicated than it has to be.
A lot of SUT's offer several settings, the Denon AU-320 has two, 3 ohm and 40 ohm. The Fidelity Research FRT-4 that Elliott just purchased has 4 settings so it covers a large range of carts.
A lot of hum and noise can be traced to poor planning, placing it next to an amp or other high power device along with running the cables close to power cables.Both Elliott and I were careful of our installation and are happy to report totally silent operation. A SUT that is set up carefully can be much quieter than an active phono stage. The quietest active MC phono stages usually cost big bucks as well.
Do you have a MM phono input now or phono preamp now, MM and/or MC? Options?

I recently asked for help here, 3 separate threads, and got good advice as usual

I started by looking for a separate Phono Preamp for my office, 2 TT, wanted two inputs, for 2 MM cartridges.

I bought the Cambridge Audio Alva Duo, nice features

Then I bought this inexpensive Pyle, MM only

Pyle’s MM sound was the same as the Cambridge, my plans changed to only 1 TT in office, kept the Pyle, returned the Cambridge. If I needed 2 TT, the Cambridge has nice features for not too much money.


Then Bill tempted me into the MC world.

I checked cartridge specs: new; vintage; damaged to be fixed by Steve at VAS, and chose a new Audio Technica for my first MC cartridge, AT33PTG-II, I absolutely love it.


My McIntosh Tube Tuner/Preamp mx110z from the 60’s has two MM Inputs, and it sounds great, so why skip it with a new external phono stage if a SUT would boost signal enough for my existing MM inputs?

sooo, Which SUT (I started knowing zero, ended very well informed). In that thread, I posted links to various SUTS with various features, as well as the others members suggested.

I like options for the future, and have two tonearms, so 1 MM arm, 1 MC Arm. PASS lets you use the SUT as a switch for MM, so 2 cartridges into 1 phono input.

After learning, and finding this Fidelity Research’s options and features, and preferring Vintage, I took a chance on it, glad I did.

3 separately selectable inputs, 4 selectable gain options, and PASS.

I plunked it down, zero noise. compared my new MC to my existing MM via PASS.

Yesterday I moved it to 3 other locations to find noise, could not do it.

10 ohm 21x, and 30 ohm 18x gain choices are very good for this cartridge. Bill, Arne and I all preferred the 10 ohm/21x factor setting for my .3mv/10 ohm cartridge, which gives 6.3mv sig (before losses), 110 ohm load to 47k phono input. (all gibberish to me before learning from members here). That leaves me a very high gain 36x and a low gain 11x option for the future.


Answer: if you don’t have a phono stage, a flexible one, MM PASS, MC with optional gain (front or internal switches, not resistors) would be nice.

btw: I borrowed my friends highly regarded Rowland Preamp, it was huge, a separate power supply, and sadly damaged, sounded awful.

btw: Prior to this McIntosh mx110z tube tuner preamp, I had a highly regarded McIntosh SS C28 preamp, had it and my Mcintosh SS amp factory overhauled. I actually preferred the AT120 TT’s little dinky built-in phono preamp’s sound to the C38’s phono stage.

So, what sounds best? It takes trial, make sure you can return what you try.

best of luck choosing,


Elliot, Not that it matters one iota to the performance of your system, but I get a reflected input impedance of 145 ohms (not 110 ohms), for your 1:18 step-up ratio into a fixed 47K ohm load resistance on your Mc phono stage.  And a step-up voltage of 5.4mV, not 6.3mV.  This is assuming that when you write "10 ohm/18X", you mean to say that you are using a 1:18 step up ratio.  Like I said, the numbers are so close that the differences don't matter, but I wonder how you made the calculations. 

I think you switched things inadvertently, the 30 ohm input is 18.27 xf, I prefer the 10 ohm setting which is 20.68 xf

actual #s from FRT-4 specs:

3 ohm input: xf 35.84; gain 31db, .3mv = 10.8mv, impedance load 37 ohms

10 ohm input: xf 20.68; gain 26db; .3mv = 6.3mv, impedance load 110 ohms

30 ohm input: xf 18.27; gain 25db; .3mv = 5.4mv, impedance load 141 ohms

100 ohm input: xf 10.55; gain 20db; .3mv = 3.3mv, impedance load 423 ohms
I used a Lundahl amorphous core silver transformer and liked it very much. As Mulveling said, they are not as warm as some others - but the clarity! Then I built my own phono/pre, and built a lot of gain into it, so now run my Koetsu platinum direct.

Differences are just an added touch of clarity, added touch of warmth, and added touch of dynamics. So I use the MM input and run the volume at 3 o'clock. Still black silent as a tomb, so there's no down side. But I suspect that if I was using a FET input stage instead of aerospace bipolar (or vintage 6922's), the Lundahl would be notably better.
denon au-320 is very nice, 2 inputs, 3 ohm or 40 ohm gain/loading options, and PASS

this one, with transformers many people respect, including Bill, has 4 different values set by switch combinations, only 1 input, no PASS for MM (it has only 1 input, so not needed).

the EAR MC4, used, 4 variations, via 4 separate sets of inputs, 3/6/12/40 ohms inputs, no PASS, only 1 input, compared to the Fidelity Research it seems poorly thought out, clumsy, were switches thought horrible things?

a few Fidelity Research FRT-4 are out there

I read  discussions in External SUT’s being used and phono stages with built in transformers ?

I thought the OP asked for a phono stage with built-in SUTs.

As for external SUT I found this model very usefull for all cartridges. 
I'm using a jensen SUT with a tavish design Tubed phono stage (mm input). This is paired with the hana el low output mc. The hana is a good match to the jensen, hana calls for greater than 400 ohms, the jensen is at 430 ohms. 

that one

offers the potential for a full line of optional transformer plug-ins, like camera lenses.

buy what you need to start, buy a different plug in later for any cartridge you buy.

labeling inputs with ohms makes no logical sense to me. I think they should give/show the x factor on the dial/transformer. that makes easier math. why not produce windings that give round numbered x factors, i.e. 6x; 10x; 14x; 20x. that's all you need to know to calculate signal strength and x factor sq is much easier to calculate.

you look for your desired load, see the x factor, see if large enough signal.

a 3 column chart: x factor/ xf sq / gain +___db

The answer to your question, originally stated, is the difference is where the process of equalization occurs,

and it is that equalization stage where the sound varies the most.

SUT’s increase signal strength with no eq, sending the stronger signal out to be equalized elsewhere.

Lack of Hum is a major goal of a SUT, good/better/best transformers and shielding.
Dear @frozentundra : "" Phono Preamp. With transformer or fully active.""

Both can works fine and if you ask on which is better the answer is that mainly depends of each unit quality design and excecution quality of that design.

In both designs you can use almost any LOMC cartridge ( the two first posts in the thread are wrong and with a high misunderstood levels. ).

It’s totally false that the transformer design unit can comes with a lower noise levels than an active design because this depends of the knowledge and skill levels of the phono stage designer.

The main limitation of a transformer/passive design could be the inherent frequency response bandwndth limitation that all transformers have at both frequency extremes where an active design has an advantage. The other issue is that the cartridge signal must pass through all the transformer wire length that makes a little more degradation than the active stage that between other advantages gives a more immediacy to what we listen it with a little more transparency/clarity that the transformer unit.

Now, if you don’t own a top LOMC cartridge but an average quality one then the choice is not so important but the unit quality design. For top LOMC cartridges the choice must be to go for the active unit.

Btw, external SUT is the worst choice and the alternative that degrades the more the delicated and sensible cartridge signal due that you need additional IC cables that means additional input and output connectors where the signal must pass and is degraded as is degraded at the solder joints in that cable and connectors and obviously through the cable wire. So with the external SUT you will have less purity in the MUSIC cartridge signal, more veiled signal and with a lot higher distortion levels.

Regards and enjoy the MUSIC NOT DISTORTIONS,

I completely agree with Raul with one important exception: "(the first posts in the thread are wrong ...)". I think that Raul has misunderstood them.

Also consider Sowter transformers. They aren't up with the big Lundahls, but they cost a tenth as much, and if you aren't using a $5k cartridge, may be preferable. OP should know that Mulveling is a connoisseur of the highest end cartridges.
Dear @terry9  : Well, part of the second post and only an opinion.  I think that I have not exactly a misunderstood as you said but that I did not be specific about. Never mind, your post welcomed.

Hi Jeff,
I can’t answer your question directly but have decided on a Zesto Andros Deluxe that uses 4 internal step up transformers for the MC stage. I don’t yet have my Zesto but have well heard the original Andros at RMAF. It uses two transformers internally for the MC stage. The Zesto sound is super clean, warm and natural sounding, Their room was, by far, the best sounding room at the show. And their system was fairly modest. Not expensive at all but the Zesto Andros made the room sound beautiful. I believe SUTs, in general, make for a super quiet and detailed sound. They are, by far, the best way to step up to MC from MM. And it is, by far, preferable to have them built in. The extra IC is problematic and it is safe to assume that when internally built in, they are a perfect match for the MM stage. My vote is for built in and Zesto. The Andros is modestly priced at $4700. And a big plus is that the Zestos are, IMO, absolutely lovely to look at. They are the best looking component there is... IMO.

4 separate transformers as step up for ?   4 inputs ?    All Mc ?



very interesting on the concept of transformers 
it does make sense 

so, As a general rule 
Transformer step up provide softening of transients ? Vs full active ? 
Dear @mglik  :  Dear @mglik  : I have no doubt that you love the Zesto unit that's a tube phono stage design.

Why LP analog alternative needs a phono stage? mainly to apply the inverse RIAA curve eq. and in second place to amplify the cartridge signal.

The inverse RIAA curve eq. should mimic the RIAA curve eq. for we can achieve a flat frequency response. This means with no frequency deviations.

The RIAA eq. is a heavy equalization process that goes from 20hz to 20khz and the eq. from around +,-  20dbs ! ! where any single deviation on that curve affects almost two octaves during the inverse eq. phono stage second process.

From some time now a good phono stage design normally comes with an inverse RIAA deviation of: +,- 0.1db but the Zesto comes with higher frequency response deviation: 0.5db that means it has a swing of 1db that's is to high and that puts additional colorations/distortions to the already inherent colorations/distortions generated by tubes.

The inverse RIAA eq. curve is critical to achieve or to stay nearer to the recording. Normally with tubes is extremely hard task to be " there ".

Yes, tube alternative is an option to the SS alternative.

With one SUT you can't use all MC cartridges, such phono stage is not universal for all MC. It will work for some of them nicely, but if your cartridge impedance is very low (2 Ohm) or very high (40 Ohm) you can't use one SUT for both of them.
This statement is false. The use of an SUT depends heavily on how its loaded at its output. This in turn is dependent on the source impedance of the cartridge.  Transformers transform impedance and this goes both ways. So you can indeed use a transformer with a 2 ohm or 40 ohm cartridge, but the loading at the output of the transformer will be quite different! And its important that this is done correctly otherwise the SUT will not sound right to say the very least.

Most SUTs made for a specific cartridge are designed to be loaded at 47K by the phono preamp, with that specific cartridge as the input. That's why they appear to be 'Use specific'. But if you loaded that SUT correctly at its output you could use it with any cartridge. This is why Jensen Transformers (some of the very best made anywhere) can be used with any cartridge, and they have a chart that shows what the loading on the output should be with that cartridge.

I prefer no transformer at all; I find that even the best SUTs seem to take something away from the detail, even if they have plenty of bandwidth (which most do). Since I run an all-tube phono preamp, this requires that I use low noise tubes. Its a simple fact that if you have a phono section with direct-in capability, whether it is solid state or tube the active devices have been hand-picked. I've noticed with our preamps that people think they can just buy a premium tube off the shelf and expect it to work. While that is sometime true its really a craps-shoot; even a premium tube might not be as low noise as you might expect. With any high performance audio equipment you have to hand pick the devices. But the result is great transparency.
Using an outboard SUT not only requires an extra pair of (expensive) ICs, it also entails passing the delicate low level signal from the cartridge through an extra pair of RCA connections (or two extra pairs, in the extreme case). The RCA plug and jack is a commercial standard but hardly a choice one would make for optimum signal transfer.  What one can do to at least partially ameliorate this problem is to hard wire the input side of the SUT to the tonearm wires.  Phono stages with built-in SUTs at least eliminate this issue.
Dear @frozentundra  : "  As a general rule...."

I own 5-6 SUTs and owned some others in the past. The ones I own are hard wired to not disturb the cartridge signal through the input/output connectors and are hard wired with 0.5m good IC cables.

My Phonolinepreamp is an active high gain design with separated/dedicated MC and MM circuit boards. Yes, the MC stage is better than  the MM+SUT and how much better depends on the SUT I use.

My favorite SUT is this vintage one by Denon and note its really wide band windth frequency response that even today SUTs can't approach in the other side note that it's a really heavy unit with 12kg.:

performs excellent and as a fact it's installed rigth now in my system.

Normally a phono stage with internal SUT are less expensive than a good SS active high gain phono stage that at the same time performs better too.

I could think that this today SUT by Audio Technica can works really fine in a good MM phono stage design:

With SUTs as these ones that " softening " is really at minimum and we can't avoid it in a SUT. These kind of SUTs asks for top LOMC cartridge models. 

But more important than if passive or active high gain phono stage is the quality of its design with main focus in the inverse RIAA eq. curve.

Everything is important in any design but exist different  priority levels in the design characteristics.

With one SUT you can't use all MC cartridges, such phono stage is not universal for all MC. It will work for some of them nicely, but if your cartridge impedance is very low (2 Ohm) or very high (40 Ohm) you can't use one SUT for both of them.

I'll differ from Ralph and agree with chakster 100% on this one.   The thing everyone misses in this discussion is the transformer needs a specific amount of inductance to assure low end extension based on cartridge internal impedance.  If you take a 2Ω cart and use a SUT designed for 40Ω, the LF extension will be down into and past record warp and tonearm resonance and the low impedance drive will cause an underdamped top end (HF peak in response). Depending how close to the audio band this happens, the results can be problematic.  Going in the other direction and using a 40Ω cartridge for a SUT designed for a 2Ω source typically will not have a full bandwidth bottom end and an over-damped top end.   The general solution to this is to design with enough inductance for the highest impedance cart and rely on a network on the secondary to fix all the other issues that arise from any mismatch.  The other typical solution is to use a dual or tapped primary that allows for different turn ratios to better suit a wider range of cartridges.  

For given source and load characteristics a wide bandwidth transformer can be wound to match the situatu


@intactaudio I don't see you commenting about the transformer loading in your post. I know that this bit is problematic:
If you take a 2Ω cart and use a SUT designed for 40Ω, the LF extension will be down into and past record warp and tonearm resonance and the low impedance drive will cause an underdamped top end (HF peak in response)
-because our phono sections go down to about 2Hz, yet there are no problems with record warp and the like. Loading the transformer is well-known to control issues in the high end- the 'underdamped' part to which you refer. So while the inductance of the cartridge certainly plays a role, its not that hard to come up with the correct loading for the transformer to make it work.

However I agree that in most cases this is beyond most audiophiles, but this does not change what I wrote. An SUT made for a specific cartridge was probably made at the behest of the cartridge manufacturer; they would probably not be happy if that transformer were used with some other manufacturer's product. So its not surprising that they don't publish loading charts for other cartridges. But if the manufacturer of the transformer doesn't have a dog in the fight, then things are different- and I point to Jensen Transformers as one of the best examples of that. One glance at all the cartridges they list shows they've done their homework!

The Jensen Transformer website contains or used to contain some excellent white papers on transformer loading, as per the subject of Intact's and Atma's posts.  They show how and why to load down the secondaries to compensate for the effects mentioned.
Dear @lewm :  A dedicated external SUT is not builded exactly the same as the transfortmers used in phono stages where the designer knows that the customer can have different MC cartridges ( needs a gain/impedance selector/alternatives. ) and their designs take in count that issue.


Are you the guys who do OTL amps?

I loved your setups with classic & their horn speakers

Do you do “ just” phono pre’s ? 
Are you the guys who do OTL amps?

Do you do “ just” phono pre’s ?
We do the OTL amps, but so far have avoided stand alone phono sections as we are convinced that they work better when they are integrated into the same chassis as the line stage, this due entirely to how the output of the preamp is connected into the line stage. When the connections are short and soldered, they seem to sound better.

Loading the transformer is well-known to control issues in the high end- the 'underdamped' part to which you refer.

I do not consider loading of the secondary of a transformer an acceptable way to control transformer behavior.  Of course there will always be some minimal load and with a known source impedance the transformer can be designed to work into that minimal load.   From a purely subjective viewpoint I have always found that reasonably well behaved unloaded transformers have sounded better than transformers forced into submission by loading.  If you start with a couple of unknowns loading suddenly becomes the only thing left in your toolbox to get acceptable results and that is the way the industry has gone.  

From a measurement perspective it is interesting to look at the HF phase response of an unloaded transformer that rings and the same transformer loaded down for critically damped response.  The link below is for the sweeps of the peerless 4722 driven from a 4Ω source with varying secondary loads.

It is interesting to note that as the frequency response approaches flat at 20kHz the phase shift increases further down into the audio band.  In this case it becomes the choice of the lesser of two evils. Since no two people hear the same, it is no wonder loading of cartridges is such a hotly contested subject when it comes to transformers.  It is my belief that often times when you adjust cartridge loading via the secondary of a SUT, the sound (and measured response) of the transformer is what is heard.  This change in sound is then falsely attributed to the cartridge seeing a different load.

Dear @intactaudio  : You posted this where we can read:

"" When we terminate the transformer with a different value, we not only change the load seen by the cartridge we change the behavior of the transformer itself! This means we are changing two parameters which creates a very unpredictable situation which goes a long way to explain why results of playing with secondary loading on SUT's has lead to such varied results since you cannot be sure what you are fixing. ""

Thank's for the link in your last post.

Hello Raul,

I actually posted that "story"on this site back in 2008.

I have some more recent thoughts on the process and measured results at the link below.


This Vintage Denon Integrated has one phono input and front switched internals for MM 2.5mv sensitivity and MC .125 mv sensitivity.

Very clean, you would need to get seller to ship if for far less money

Denon excerpt: Phono 20-100k, 0.2db

The MC/MM super equalizer is carried and the broadband characteristic of 20Hz-100kHz�}0.2dB is realized.
Composition consists of the NF form direct-current amplifier and CR form equalizing filter by newly developed low noise dual FET, and the first rank serves as dual FET differential amplification of the direct direct-current servo system.
Dear @intactaudio : I always say: " every day is a learning day " and througgh your last post confirm it. Really enligthing ! ! in a way " torture road " and sometimes controversial critical and important subject.

Thank's again.

Regards and enjoy the MUSIC NOT DISTORTIONS,

A number of years back I always found it odd that it seemed that there were two camps on loading of MC cartridges.  One camp insisted that 47KΩ was the proper number and changing it made little difference.  The other camp was fanatical down to the single Ω precision and it was always a fraction of the 47kΩ number.  It coincided that the 47kΩ crowd all used active gain stages and the fraction faction used SUT's.  If I assumed the 47k-ers to be correct and loading had little sonic effect, it seemed logical that the loaders might be effecting some other change than the sound of the cartridge and I started looking more closely at SUT behavior.  This has lead me to my current belief that when you load the secondary of the transformer you  change the sound of the transformer more than that of the cartridge.  

The wrinkle to both of the situations above shows up when you consider current injection behavior for MC cartridges where the load tries to become a dead short.  This one really bothered me until I read an article by Peter Moncrief in IAR#5 where he makes a convincing argument that loading a MC cartridge does not appreciably change the measured frequency response but it does have a marked effect on how much IM distortion is created.  What I found interesting about this concept involves the general sonic terms used for the for the reduction of IM distortion and two new warring factions were created in my head. 

The "Dampers" use the loading to explain the taming of a rising top end inherent to the MC topology.   A light load causes a rising response, and a heavy load causes the top end to roll off turning things into mud.  Somewhere in between the two one finds a safe middle ground and can live in peace.  A number of years back I split from this faction since the easily measured behavior of the SUT showed this behavior to a far greater extent than the measured cartridge behavior.

The "Loaders" lead by Moncrief simply state that the etched detail of an unloaded cartridge is an excess of IM distortion artifacts and when those artifacts are reduced, the seemingly dull sound is actually correct and the result of a series of system wide decisions previously made to offset the overly forward sound of the unloaded cartridge.

Everyone considers this all to be a black art and in reality it is simply a puzzle where all of the pieces fit together.  When you find two pieces that  seem to join but the pictures do not match you need to keep trying to see if you find a better fit.  Taking parts of truth from all of the factions above I am slowly coming up with a picture in my mind of how this all fits together in a predictable and repeatable manner.  Obviously I make SUT's so I'm going to explore those options.  You prefer an active stage so that is where your biases are.  Tubed vs. solid state are a couple of more of the warring factions.  This is where the subjective results come into play and ultimately we choose and follow the path that gives the most musical enjoyment.  That doesn't mean we shouldn't occasionally check our GPS when we start seeing the occasional polar bear.


Dear @intactaudio : "  I make SUT's so I'm going to explore those options. You prefer an active stage so that is where your biases are. Tubed vs. solid state are a couple of more of the warring factions. This is where the subjective results come into play and ultimately we choose and follow the path that gives the most musical enjoyment.   "

Agree with. I use both alternatives.

Btw, after I seen a picture in your site I took in count that if I remember ( maybe I'm wrong. ) this gentleman @mikelavigne   posted that he listened or bougth ( ? ? . ) the silver wired SUTs and maybe you can confirm it or not because if I'm rigth then I remember too that he touted those SUTs:

Regards and enjoy the MUSIC NOT DISTOPRTIONS,


right you are. i enjoyed my EMIA Ag 1:10 SUT so much, i purchased a second identical one for my other cartridge.

here is a picture: (scroll down the post to the last picture) .

my CS Port phono stage has one MC 63db gain input, and 2 40db gain, 47k ohms loaded inputs. so i’ve added those 2 SUT’s from Intact Audio and the performance is outstanding. there is a sexyness to these SUT’s superior to any high gain active phono pre i’ve heard.

added note; i worked for a couple of months with Dave Slagle with Intact Audio, tried a few different SUT’s, and ended up with the perfect one’s for my situation. Dave was awesome to work with and held my hand through the process. thank you Dave! you don't need to be a techie to use an SUT.
In order to add a bit to the road Mike went down his first audition was with two pair of identical 1:20's, one in silver and the other in copper.  Initially the silver was preferred and after a few weeks he found that the internal SUT's to the CS Port offered some benefits over the 1:20's he had in system.  A little bit of sleuthing turned up the distortion spec of 0.1% @ 0.76Vrms output.  Working this number backwards from the 40dB of gain this translates to 7.6mV of input.  The Etsuro Gold has 0.56mV of output and fed to a 1:20 that will be slightly above the 7.6mV level.  It turns out that the CS Ports internal SUT had 3dB less gain which using simple math put the output right at that published distortion number which is why I suggested that mike try a 1:10.  I sent him a copper 1:10 for his 4Ω Etsuro and things improved over the internal SUT.  Replacing the copper with silver was the icing on the cake that he is currently consuming.  

I think the important thing to note about this is the high frequency overload characteristics of phono playback is typically not pretty.  At high frequencies many phono stages seem to have a more abrupt transition into distortion where the higher order artifacts show up and quickly dominate.  This high order high frequency distortion only happens at dynamic peaks nearing the highest possible groove velocities.  Holman notes a worst case 105cm/sec peak @ 7Khz on  Woody Herman Verve V-5885 and that represents 26dB above the standard 5cm/sec velocity referenced to 1kHz.  Granted the 7kHz signal receives 10.7dB less gain but that still leaves a 15dB dynamic peak above the 1kHz baseline.  It is these periodic events tickling the abrupt onset of distortion that I find gives a "something is not right but I'm not sure what it is" type of feeling.  It is the periodic occurrence at dynamic peaks that make it so elusive.   The trend as of late is for MC carts with 6dB or more output than their predecessors which simply translates to a 6dB loss of high frequency dynamic headroom when considering a MC stage built with a 0.2mV SPU in mind.  10 years ago a 1:10 was an anomaly and today with MC outputs in the 0.5mV to 1mV range it is slowly becoming the norm.


Dear @intactaudio :  From some years now LOMC cartridge designs comes with higher output levels than in the past.

That healthy higher output makes a more easy way for phono stages to handle LOMC designs, especially tube electronics but that healthy output comes with a trade-off in the overall cartridge quality performance levels.

If that Etsuro Gold instead of 0.56mv came with say 0.15mv I have no doubt that @mikelavigne  will be even more happy that with his already great Etsuro samples quality performance.

Problem is that 0.15mv can be a problem even for SS phono stages. Nothing is perfect but normally lower output mv means less wire in its coils with more powerful magnets as neodymium ones.

Lyra is a good example about when JC started with his Atlas/Etna models and latter on he presented the new same models in low output fashion and owners and reviewers gone with a smaLL PREFERENCE FOR THE LOWER OUTPUT MODELS.

I remember what happened in the past with some of the LOMC cartridges I owned, example: AT MC 1000 that was marketed along its dedicated SUT AT 1000T for its low 0.1mv output or the Ortofon MC2000 that appeared along its dedicated SUT T-2000 for its very low output of 0.05mv and the same was with Audio Note design. 
All those cartridges came with very high quality level performance but not easy to handle for phono stages, certainly not tubes designs.

Latter on I remember my first Colibri with a not so lower but certainly not something approaching the Etsuro output, this Colibri had 0.21mv and performed excellent in quality kind of sound. Latter I bougth two other Colibri samples but VDH only offered with higher output and I have to say that nothing like the " original " 0.21mv polymer cartridge body.

Anyway, good that both of you are satisfied with.

It is interesting to note that as the frequency response approaches flat at 20kHz the phase shift increases further down into the audio band. In this case it becomes the choice of the lesser of two evils. Since no two people hear the same, it is no wonder loading of cartridges is such a hotly contested subject when it comes to transformers. It is my belief that often times when you adjust cartridge loading via the secondary of a SUT, the sound (and measured response) of the transformer is what is heard. This change in sound is then falsely attributed to the cartridge seeing a different load.
@intactaudio Why would you want to adjust the cartridge loading? I agree entirely though that loading the transformer is for the benefit of the transformer and not the cartridge- what it appears you're also saying here. That is what I was saying earlier as well, if that was not clear.

An SUT that has troubles making it to 20KHz it is a bit troubling- I would expect 50-70KHz at least on a part with that little power requirement. But that is of course ignoring the inductance of the cartridge... But your graph didn't suggest anything about that. 

This is kinda off track , but transformer, based 

Mac amps ?  Claim they are “ auto-transformer” coupled.

what does that mean ?


ps: what is sound difference between a preamp with & without transformers?

Cartridge loading is another hotly contested subject that is best to save for a new discussion.  It seems we both agree that applying a load through the secondary of a SUT has a much greater chance of changing the SUT behavior in an audible way than the cartridge behavior.

The inductance question can be answered by looking at SUT behavior when driven from various cartridge impedances.  The plot linked below is the 4722 wired 1:18 driven from 2Ω to 100Ω and at 100Ω the -3dB point is ~10Hz which translates to 1.6Hy.

I chose the 4722 because it is a known device that represents the typical behavior of a microphone transformer pressed into SUT usage.  I agree that the top end behavior of this device leave a lot to be desired. When paired with an EMT or a Denon 103 into a 47K load it is -1dB @ 10Hz and 20kHz and has what many call a "vintage" sound.  As an aside, Bell Labs did a lot of work on voice transmission and intelligibility and found that linearity in the phase domain was far more important than linearity in the amplitude domain.  They considered the range from 600hz to 4Khz the critical range and found that phase shifts creeping down below 4kHz tended to muddle the voice.  I agree that the audio bandwidth is much larger than that required for voice but it is interesting to note that the phase shift of the 4722 does creep down into that "sacred area" that Bell Labs found had an impact on intelligibility.   I just measured some 900:900 Western Electric repeat transformer that had a specified frequency range of "Voice" and 425Hz-1615Hz was mentioned.  When fed from a 50Ω source and left unloaded the -1dB points were 18Hz and 2.4Mhz.  I don't think the crazy high top end bandwidth was an accident and the phase stays flat to 100Khz. 
I chose the 4722 because it is a known device that represents the typical behavior of a microphone transformer pressed into SUT usage.
18:1 seems like a lot of stepup to me, but at the same time I suspect that 4722 is intended for an input inductance that is a bit different, being that its a mic transformer.
18:1 is a bit on the high side for a 103 but not terrible.  Problem with the higher step up and the 40Ω cart is any capacitance on the secondary claims the 20kHz+ info quickly.  The 103 is a 0.3mV cart and into a 1:18 loaded with 47K you get really close to the 5mV "Norm" for most mm inputs.  Now 1:70.... that is high... but also a perfect fit for a 0.05mv cart into the right cable / pre combo.

I don't see where the inductance comes into play here.  as long as there is sufficient inductance to cover the low end without going too low it falls out of the picture.  

An interesting anecdote about the 4722 and its ilk which can be wired 1:18 / 1:36 is you get just about the same output due to the 1:36 loading the cartridge below its internal impedance and the frequency / phase plots are quite similar with the 1:36 losing a little more than 1/2 a dB @ 20Hz & 20kHz.  I know of a few people who simply prefer the 1:36 hookup and given the similarity of the measured response of each it makes me wonder if any of this preference is due to the drastic load improving traceability ala Moncrief.  I know this seems in contradiction to what I said above but in this case the loading in both cases is right where the transformer was specified (ie 50K load) and the measured responses are similar so I see a window of possibility.  An unfair test would be to load the 1:18 setting with an additional 16K on the secondary and compare it to the 1:36 with a typical 47K.  The proper way to test it would be to simply parallel 55Ω with the primary of the 1:18.  The gain would be down around 4-5dB but the frequency response would minimally change.'

When I look at the specs of the 4722, it seems its bandwidth might be limited by the simple fact that it is meant to deal with a signal much stronger than that of a LOMC cartridge.  Or it might simply be that Altec didn't intend the application for much more than public address. But whatever the reason, by comparison on paper, any Jensen SUT transformer outperforms it in every way- take a look:

 There's a bit of cult around the 4722, isn't there? One not from actual performance, right?
I specifically chose the 4722 to avoid the appearance of throwing another manufacturer under the bus so to speak.  The only place I have seen signal level have an effect on frequency response in SUT's was with units wound on cores with poor low level permeability in which case the bass disappears. 

I'm not sure of the origins of the cult of the 4722 but I do think you can do much better.  The jensens are nice but I do not consider the use of the rather heavy secondary load in addition to a Zobel as a sonically acceptable solution.  

I do not consider the use of the rather heavy secondary load in addition to a Zobel as a sonically acceptable solution.  
FWIW they *are* designed for that. I totally agree regarding your comments about bad core design- my comments  presume a decent transformer to start with :) ...   I think the 4722 cult has to do with a recording engineer named Eddie Ciletti.