This discussion is beyond my pay grade.
I do believe that whatever the transformer it is dependent on the performance of the phono amp it is attached too. I have installed Sowter transformers ( they have several units designed for various cartridge impedance) in several phono amps the last one being an ARC PH 3 SE.
All I can say is that it was an easy job and it worked wonderfully well. For best performance the transformer have to be installed within the phono amp. It is also very cost effective. I have also used Sowter's ESL transformers in my Acoustats with great results.
Having said all this I prefer a fully active design. I am particularly enamored by Channel D's new units. They run in current mode and have battery power supplies that isolate the units from the mains. They are the quietest units on the market and not by a small margin. |
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Jensen named the parts of the Zobel Rdamp and Cdamp which clearly tells
its purpose. I do not know of any phono stage inputs with those parts
intentionally in place. @intactaudio Our preamps allow that- if we install the transformers internally (an option) then the output of the SUT is set up so the external loading strip on the preamp is loading the output of the transformer. If the transformer is external, obviously the same is true. So any Zobel or simple loading resistor can be installed with ease. I agree as well that if the aberrant behavior is a peak at 200KHz probably best leaving it alone. |
@dover if the 22 tubed NVO has too many tubes you should hear the 13 tubed NVO. So very close
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If one choses to use a loading network and likes the sonic results, that is fine. I have always found that sonically, loading is the worst thing you can do to a transformer and using anything more than the absolute minimum required is relying on a band-aid for a preventable injury.
I said I could hear a difference altering the zobel network, I did not say I liked the sound. I tend to agree with you on loading - either primary or secondary. I am in the Jonathan Carr camp where I dont believe loading modern moving coil cartridges impacts the cartridge behaviour. Loading a cartridge impacts the following phono stage behaviour - for example poorly designed solid state phono stages with low overload margins at ultra high frequencies. In selecting transformers for MC’s in my experience it is better to focus on getting the gain into the optimum position for the ensuing phono stage rather than worry about what load the cartridge sees. I have still sitting in the cupboard - Altec 4629’s, 4722’s, Jensens, FR’s ( ugh ) and an Ortofon. Have previously heard many others. None of them are neutral, they all have their own idiosyncratic sound. Even optimising the gain structure, moving coils and step up transformers are like a pot luck dinner - you never know what you are going to get until you try it. And they still have the aforementioned phase anomalies across the audio band. I heard a Zesto vs a NVO phono and the NVO Yes I’ve heard both. The Zesto is good value for money, the NVO ( all tube, no transformers ) is very good. My only reservation with the NVO is the use of 20+ tubes in it. If 1 goes noisy what a drama finding it. This would drive me nuts ( and I’m a tube guy ). |
For what it's worth I heard a Zesto vs a NVO phono and the NVO was clearly the superior don't know why there's not much talk about NVO, several yrs ago it was much talked about even on these forums.
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Dover, This simply means that the Zesto added the network in order to deal with the transformer behavior. That is very different than having a phono with that network at the input and then designing the transformer to work into it. This is an easily solvable chicken or the egg paradox. My response asking about this was in relation to the quoted exchange below 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 took this to mean that the transformers were designed to work into that specific network which made me question where that network actually exists to require that transformer design to naturally work into it. You said above: The reality is that transformers are non linear in both amplitude and more importantly phase. It is the phase anomalies that kill the music - musical timing and natural harmonics are destroyed by phase anomalies.
If the time domain is more important than the amplitude domain then what is the logic of using a network on the secondary that corrects for the amplitude domain at the cost of additional phase shift in the time domain? The link below shows the simulation of a hypothetical transformer with and without a Zobel network to damp ringing at high frequencies. http://www.intactaudio.com/forum/files/screen_shot_2020_08_02_at_81425_am_139.pngIf one choses to use a loading network and likes the sonic results, that is fine. I have always found that sonically, loading is the worst thing you can do to a transformer and using anything more than the absolute minimum required is relying on a band-aid for a preventable injury. dave |
Which phono stage is this? Zesto 1.2 uses Jensen transformers with zobel network in place. |
I do, it retails for $3500 and has had stellar reviews.
Which phono stage is this? I agree with you on the phase issues and at some low and high frequency a transformer is going to shift phase and I think that the shift at high frequencies is much more of a concern than at low. musical timing and natural harmonics are destroyed by phase anomalies. yes.... bell labs found a strong correlation between phase shifts and voice intelligibility. Higher order odd harmonics are dissonant to begin with, throw in some phase shift and i suspect they get downright ugly. Look at the bottom end in your graphs - its there for all to see. I don't follow. transformers like all systems have a finite bandwidth and with that they have finite linear phase. It is much more of a struggle to get a full 10 octaves of flat phase response out of a transformer than an active circuit so it becomes increasingly important to place the plateau of linear phase in the proper spot. dave |
Jensen named the parts of the Zobel Rdamp and Cdamp which clearly tells its purpose. I do not know of any phono stage inputs with those parts intentionally in place I do, it retails for $3500 and has had stellar reviews. It would be interesting to see the response without the Zobel in place to see what it is hiding. It supposedly minimises internal ringing in the transformer. If you simulate the load of the cartridge and run a square wave through the scope you can adjust the zobel to suit. In the afroementioned phono stage I have personally exerimented with altering the zobel to match the internal imedance of the cartridge, it is clearly audible. The reality is that transformers are non linear in both amplitude and more importantly phase. It is the phase anomalies that kill the music - musical timing and natural harmonics are destroyed by phase anomalies. In my experience, with an array of moving coil stepup devices to hand including both tube and solid state active, and many much vaunted transformers, is that active devices, for all their faults are more musically compelling. Play any jazz record where there are changes in tempo within the track and a comparison between a competent active stage and a competent transformer will highlight the transformers destruction of phase and timing. Look at the bottom end in your graphs - its there for all to see. |
I might have been a little unclear above when I typed: I do not consider the use of the rather heavy secondary load in addition to a Zobel as a sonically acceptable solution. That should read: I do not consider the use of the rather heavy secondary load in the form of a Zobel as a sonically acceptable solution. I will add that the load from the Zobel is at higher frequencies only. Jensen named the parts of the Zobel Rdamp and Cdamp which clearly tells its purpose. I do not know of any phono stage inputs with those parts intentionally in place. It would be interesting to see the response without the Zobel in place to see what it is hiding. I for one do not have a problem with a Low Q 2-5dB peak nearing 200kHz and find that any resistance or network added to tame it does more harm than good. The 4722 or other vintage mic transformer turned SUT showing the peak in the 20-40kHz range is another situation altogether. http://www.intactaudio.com/images/SUT%20white%20paper/4722%20vs%20emia.pngdave |
Boy;
Who would have thought SUT’s are so controversial in application. My 2 buddies , that are LP guys, both have fully active with lots of adjustability.
Their systems sound superb, with a Lyra & Purpleheart cartridges
I think it’s best to start fully active, as it appears
Being a vinyl , newby,
Then listen and see how it goes
jeff |
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. |
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.
dave |
@intactaudio 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: https://www.jensen-transformers.com/transformers/moving-coil/ There's a bit of cult around the 4722, isn't there? One not from actual performance, right? |
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. http://www.intactaudio.com/images/SUT%20white%20paper/4722.png' dave |
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. |
Ralph, 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. http://www.intactaudio.com/images/SUT%20white%20paper/4722%20cart%20z.pngI 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. http://www.intactaudio.com/forum/files/phase_385.png |
This is kinda off track , but transformer, based
Mac amps ? Claim they are “ auto-transformer” coupled.
what does that mean ?
jeff
ps: what is sound difference between a preamp with & without transformers? |
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. |
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.
R. |
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.
dave
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@rauliruegas 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) https://www.whatsbestforum.com/threads/etsuro-gold-mc-cartridge-in-house.29780/page-10#post-662650 . 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. |
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:
http://www.intactaudio.com/images/Tran_images/canned%20SUT_SM.jpg
http://www.intactaudio.com/tran.html
Regards and enjoy the MUSIC NOT DISTOPRTIONS, R. |
Raul,
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.
dave
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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,
R. |
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Dear @intactaudio : You posted this where we can read:
http://www.intactaudio.com/forum/viewtopic.php?t=752#top
"" 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. R. |
Ralph... 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. http://www.intactaudio.com/images/SUT%20white%20paper/4722%20load.pngIt 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. dave |
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. |
@atmasphere
Are you the guys who do OTL amps?
I loved your setups with classic & their horn speakers
Do you do “ just” phono pre’s ?
Jeff
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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.
R. |
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.
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@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! |
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 dave |
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.:
https://www.denon.jp/ja-jp/museum/products/au1000.html
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:
https://www.audio-technica.com/cms/accessories/1211e0cd29d5d0aa/index.html
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. R. |
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.
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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. |
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.
R. |
@rauliruegas
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 ?
Jeff
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Mglik;
4 separate transformers as step up for ? 4 inputs ? All Mc ?
interesting
jeff
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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. |
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.
R. |
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 @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,
R.
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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. |
chackster, that one
http://www.auduo-1.com/newgoods/K-L/LUXMAN/TYPE8020_TYPE8030/TYPE8020_TYPE8030.html
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 |
