MM vs. MC: What Happens When People Jump Into MC Too Early? 


MM vs. MC: What Happens When People Jump Into MC Too Early? 

The decision to purchase an expensive moving-coil cartridge rarely happens immediately. Most music lovers arrive at that point only after spending some time with vinyl.

Perhaps they started with an entry-level MM cartridge, or they already own an affordable MC cartridge. Or perhaps they started with a carefully selected vintage MM cartridge, as I suggested in my article – The Best Vinyl Sound For $1000, and discovered just how much performance can be achieved without spending a fortune.

But after a year or two of listening, reading forums, watching reviews, and talking to other audiophiles, a question inevitably appears:

What am I missing?

What would happen if I installed one of those expensive MC cartridges that audiophiles praise so enthusiastically?

What about Lyra Delos, or some highly praised retipped vintage MC cartridge?

Before we go any further, it is worth mentioning another group of audiophiles—more experienced vinyl enthusiasts—the ones who have already spent several years with analog playback and dream of eventually building a serious turntable with two tonearms, just like the systems they admire on Instagram.

Whenever I asked people planning such systems what tonearms they intended to install, the answer was remarkably consistent:

“One light tonearm and one heavy tonearm.”

In my experience, both approaches lead to expensive detours.

The first mistake is trying to jump into the MC segment before you can afford a solution that really works.

The second is spending a fortune on a two-arm turntable without fully understanding what those tonearms are supposed to accomplish, rather than pursuing a more versatile path.

To explain these mistakes, we need to go back to the beginning.

Cartridges Evolved Together with Records

Phono cartridges did not develop in isolation. They evolved alongside the record itself.

Nobody would seriously consider playing a shellac 78 RPM record with a modern microline MC cartridge. Those records were designed for stylus profiles that, by modern standards, look almost like sewing needles. In many ways, the same principle applies throughout the history of vinyl playback.

As record manufacturing evolved, groove geometry changed. Grooves became narrower, cutting techniques became more sophisticated, and playback equipment became increasingly refined.

Simultaneously, stylus profiles grew more complex. Cantilevers became lighter and stiffer. Magnet structures became more advanced. Cartridge designers continuously searched for new ways to extract more information from the groove.

Many of the moving-coil cartridges that appeared during the 1970s and early 1980s were genuine advances over the moving-magnet designs of their era.

Evaluating those cartridges today, however, is difficult. Unlike vintage MM cartridges, many of which can still be restored to near-original condition simply by installing a modern replacement stylus, a moving-coil cartridge is a much more integrated device. The stylus assembly is not a user-replaceable component but part of the cartridge’s entire mechanical and electromagnetic structure.

As a result, original factory styli for most vintage MC cartridges are long gone.

Restoration typically requires retipping by a specialist, often using a completely different stylus profile, cantilever material, or suspension system than the original design. Sometimes the results are excellent. But what emerges from the process is no longer the same cartridge that left the factory decades ago.

However, cartridge technology did not stop in 1980.

Advances in magnet materials, stylus geometry, coil design, and manufacturing precision have continued for decades. As a result, with only a handful of exceptions, even many of the most celebrated vintage MC cartridges struggle to compete directly with the best modern designs.

What Happens When People Upgrade Too Soon?

What usually happens when people jump into the MC segment with only $1-2K and buy something like Lyra Delos or a similarly priced cartridge?

Some records immediately sound better.

This is especially true of later pressings, where groove geometry became narrower and more sophisticated. Suddenly there is more air, more detail, a deeper soundstage, and a stronger sense of separation between instruments.

The owner smiles and says:

“I knew it. MC really is better.”

Then something else happens.

He pulls out an older record—perhaps Grand Funk Railroad, Nazareth, or Led Zeppelin.

And the reaction becomes less enthusiastic.

The sound is detailed, but somehow less convincing. The music feels more analytical, less cohesive, less emotionally connected. Instead of hearing a performance, the listener begins hearing individual elements of the recording.

Many of the records that define the golden age of vinyl were recorded between the late 1960s and the mid-1980s. Their groove structure and cutting techniques differ substantially from later digitally mastered records, and while the fine stylus of many MC cartridges can extract more information from thin grooves than thicker MM styli, when it comes to the older records with wider grooves – less delicate MM cartridges often produce a more coherent and natural presentation. If you let me use an automobile analogy again, this is like driving a sports car on a highway and a 4x4 off-road.

The Two-Tonearm Solution

This duality brought many music lovers to the two-tonearm solution. Between 2015 and 2018, I built a dozen vinyl systems around exactly this concept. One tonearm carried a cartridge, such as a Shure V15 or an ADC XLM, for earlier records. The second initially carried an Audio-Technica AT33, but its tonal balance was surprisingly similar to the ADC XLM. To make the setup more interesting, I developed my own product, Denon Goliath - a modified Denon 103 that I extensively reworked with retipping and a custom wooden-body conversion. The result deserves a separate article.

It was through the Denon Goliath that I first rediscovered later recordings such as Iron Maiden albums from 1986–1988. For the first time, I heard how much information these records actually contained. Compared to the MM cartridges I had been using previously, it felt as though ten to fifteen percent of the information in the groove had not been retrieved.

These two-tonearm systems were remarkably versatile. They handled both older and newer records with equal confidence and provided an elegant solution to the problem. I used vintage Victor or Denon direct-drive motors and custom plinths to build those turntables, and for that period, they were a perfect audiophile product within a budget below $6000.

And yes – one tonearm on that type of player was light for high-compliance vintage MM cartridges, and the other was heavy for a low-compliance Denon.

Why is it a costly mistake to use the same solution today?

The economics now are very different. Many vintage motors have reached the end of their practical service life and require extensive restoration. A modern turntable capable of accommodating two tonearms, together with the required armboards and tonearms, can easily exceed $15,000–20,000 before you even start thinking about cartridges.

At the same time, today we have My Sonic Lab cartridges that combine very high resolution with a surprisingly natural and balanced presentation across a much wider range of records than was previously possible.

And this is the key point.

Today, buying a versatile My Sonic Lab cartridge and one good tonearm for it is a much smarter decision than a two-tonearm solution. Even the entry-level My Sonic Lab models can compete successfully with combinations that would previously have required two separate tonearms.

As a result, the traditional solution of maintaining separate cartridges for different eras of records becomes much harder to justify when working within a limited budget.

For listeners seeking a turntable capable of reproducing an entire record collection with equal confidence, the most sensible strategy today is often to aim directly for a My Sonic Lab cartridge and a single 12-inch tonearm with low-to-medium effective mass. In my practice, the Moerch DP8 12-inch red dot worked best, but common SME tonearms work perfectly well too, except for heavier models such as the 3012R or M2-12R.

 A Quick Word About Lyra

No discussion of MC cartridges would be complete without mentioning Lyra.

On this website, you will find a separate review of the Lyra Delos, one of the most popular first MC cartridges. In that article, I explain why I rarely recommend it. However, that does not mean it is a bad cartridge. In fact, for many listeners it can be exactly the right choice.

Many entry-level and mid-level high-end systems suffer from a lack of overall transparency. This is often caused not by the cartridge itself, but by the system as a whole. Loudspeakers may have a high Effective Drive Mass, amplifiers may deliver insufficient current, and the entire system may sound slightly closed-in.

In such systems, the energetic and highly detailed character of a cartridge like the Lyra Delos can be extremely beneficial. The cartridge effectively cuts through the system’s overall lack of openness, creating more air, more apparent detail, and a greater sense of excitement.

This is precisely why opinions about Lyra cartridges are often so polarized.

One listener installs a Lyra and immediately falls in love. Another listener hears the same cartridge and finds it overly analytical or fatiguing. Both listeners may be correct. The difference is the system.

So, Should You Upgrade to MC?

My answer is yes, absolutely.

A properly chosen MC cartridge can absolutely deliver a meaningful improvement in analog playback.

The mistake was upgrading without sufficient funds and purchasing an MC cartridge that lacks versatility.

If your system is already highly transparent—sensitive loudspeakers, low Effective Drive Mass, sufficient amplifier current—I would suggest looking toward a cartridge no less than the My Sonic Lab Eminent EX or better, such as the My Sonic Lab Hyper Eminent.

If your system still lacks overall transparency, a cartridge such as the Lyra Kleos may be a good choice, but I recommend addressing the lack of transparency first and then moving to the My Sonic Lab Hyper Eminent anyway.

If your budget for an upgrade is less than $4K, which would allow you to afford Lyra Kleos or a My Sonic Lab Eminent Ex, I would not rush into MC cartridges at all.

Don’t forget that if your phonostage doesn’t properly support MC cartridges, you will need a SUP and a cable to connect, which adds at least $1-2K more.

A properly restored vintage MM cartridge, such as a Shure V15 or an ADC XLM, remains one of the smartest purchases in analog audio below the $4K threshold. More affordable MC cartridges improve certain aspects of reproduction while simultaneously sacrificing others. You gain something on one group of records and lose something on another, and the result is often not a breakthrough, but a compromise.

If your budget allows, skip the intermediate steps and move directly toward a truly versatile design such as the My Sonic Lab.

Does a two-tonarm solution make any sense today?

Oh, yes, but on a much higher level, where lies a very different world of pushing analog playback to the limit. In this game, the goal is no longer versatility.

The goal becomes specialization.

Coming back to the automobile analogy again – BMW X6 is excellent both on a highway and a moderate cross-country, but if you want to set lap records at a racetrack and compete in the Camel Trophy, you need two totally different cars – let’s say a Ferrari and a Defender.

Different cartridges and different tonearms are optimized for different records from different recording eras. This approach can extract the absolute maximum from the medium, but it also requires a completely different level of investment. The threshold begins at roughly $35K, and with the necessary infrastructure – step-up transformers and cabling – it can easily reach $ 45K–$50K. And in this game, the formula “one light-mass tonearm and one heavy tonearm” doesn’t always apply. Some of the best contemporary setups need two heavy tonearms because both cartridges, specialized for records from early and later eras, are low-compliance.

The core of this article is that choosing between MM and MC cartridges is not the real question.

The real question is whether you are optimizing your setup for budget, versatility, or specialization.

At the first level, the goal is straightforward: achieve the best possible sound within a comfortable budget. And vintage MM cartridges like the Shure V15, ADC XLM, and others with Jico styli outperform most existing low-priced MC cartridges, both contemporary and vintage.

The second level begins when the goal of achieving better sound meets a meaningful upgrade that works equally well across a wide range of records. Here's where My Sonic Lab cartridges stand out as one of the most compelling solutions available. If you already know you have no interest in building a $35,000-plus analog front end in the future and that extracting the absolute last few percent of performance from vinyl is not your goal, then a simpler, more universal approach makes perfect sense. In that case, I would focus on turntables that can accommodate a quality 12-inch tonearm but do not necessarily require multiple tonearms.

How Far Down the Rabbit Hole Do You Want to Go?

If, on the other hand, you believe that analog playback may become a long-term passion and that one day you may want to pursue the specialized approach discussed in this article, it may be wise to choose a turntable platform with greater long-term flexibility.

In that scenario, a single universal cartridge such as a My Sonic Lab can serve as an excellent starting point. Later, as priorities and experience evolve, the same turntable can become the foundation for a more specialized two- or even three-tonearm system.

The challenge is that the right answer depends not only on your budget, but also on your goals, your record collection, and how you plan to enjoy music in the years ahead.

If you would like to hear all the cartridges mentioned yourself rather than read about them, I encourage you to visit the REFERENCE VINYL RECORDINGS page.

Reference Vinyl Setup No. 1 in that collection was built around the very concept discussed in this article: a turntable with two specialized tonearms, one optimized for older records and the other for later pressings. Incidentally, that turntable used two heavy-mass tonearms, not the traditional “one light and one heavy” combination.

The Reference Track 1 and Reference Track 2 collections contain recordings made with a wide variety of cartridges, including vintage MC designs and modern cartridges from different price categories.

Well-known and relatively expensive MC cartridges occupy the last two positions. Yet despite their price and brand name, they are outperformed by cartridges ranked much higher—including a humble Shure V15 mounted on a very modest turntable. More importantly, that particular Shure was used in a stock configuration. It did not benefit from many of the upgrades I would normally recommend, such as a top-level JICO stylus with a boron cantilever, a wooden headshell, or mounting it on a 12-inch Moerch. Had that Shure received all those upgrades, it would have been higher in the list, closer to the top 5 positions occupied by the best modern MC carts.

I hope the information in this article—and the accompanying reference recordings—helps you make more informed decisions about your analog front end.

Paul Gerbert, Independent Audio Consultant

Helping audiophiles navigate an expensive and confusing hobby through smarter decisions and long-term planning.

Disclaimer: I don't sell My Sonic Lab cartridges, Lyra cartridges or any other gear mentioned in this article.

colossalsound

@kennyc The best way to not overspend is to loan, I've experienced in my home system 10+ SUT's and, not too far back, 3 Head Amps all produced as variants of a design and all discernible for what they were capable of, which was notable.

Outside of the home, where I have loaned Phonostages to others over the years, I have approx' another 5-8 SUT's demoed to me in a non-owned phon' and my own Phon'. I think it fairer to myself to state, I have not kept count, and these may be leaning to an underestimate of different experiences had, as audio shows and forum events are not added as experiences.  

My experiences, which, as can be seen, are quite limited, when considering the wealth of permutations for auxiliaries to support a MC Cartridge. Have led me to the place where I can state with conviction that I have concluded that SUT's are varying in how Richness of Tone is able to be perceived. My attraction is leaning towards the perception of transparency, with the low end being fleet-footed. My repellent is when the Tonal Richness is very noticeable, and there is a trudge to the bottom frequency. I've heard much and have a list I would own, and a list I certainly would not own, but my choices will be the antithesis to another's.

I find SUT's very attractive, I have used them for multiple hours without desiring change, but here is the juxtaposition: after a period of usage, I find myself sensing that the tonal richness delivered by the owned SUT's will benefit the replay more.

The SME V-IV talk between a few individuals is a repeating subject on the Gon. I have found myself a contributor writing about the same experience on more than one other occasion. 

There is no content I see that is changing my mind or making me doubt my choice made relating to the IV being the choice over the five when made all those years past. I do know the IV is never going to be the Numero Uno TA in my own system again. I do see my wife inheriting it or another superseded TA for her TT when it is readied for her.  

Anything I say about the IV is a subjective evaluation, and I don't see any other content on the Gon over the years that is anything but subjective or conjecture.

Even the Hifi News comment is strictly limited to referencing the Wand Only , that could simply mean a V Wand needs less surface treatment prior to a coating being applied. The Magnesium is the desired property as the material, and the IV has that in the same abundance as the V.

New info for me in the recent posts is the reference to the Gramophone Article, which, as a summary, I am not struggling with as the evaluation, as it shares similarities to my own written info. 

On the subject of Magnesium, I have a Cartridge Keeper with a fair cache of 9g Mg Headshells, possibly made prior to the V or IV being a concept.  

Don't overlook the RB 300 from Rega, which was marketed from 1983, three years prior to the V becoming a marketed product.

The common story (note: story) in the UK is that the Rega RB300 left multi-part and multi-jointed Tonearms offered for sale dead in the water when it came to purchases being made. SME, being reactive, botched a prototype Rega Clone together as an attempt to draw market interest and did not get a product released until three years later, as stated (note: story).

Personally, I have for numerous years viewed the SME V and IV along with a selection of other alternate companies' arms released as piggybacking on Rega. Was Rega a victim of IP Theft?   

 

Save your money stick with mm...listen with your ears and mind not your wallet....more isn't always better.

Dear @billstevenson   : Things are that one of my best friends and audio friend too is a professional drum playes and a designer/manufacturer of full range horn speakers.

He always use ears protection when playing with his group.

One time he bronguht to my home place his overall instrument that I listen at his house many times and obviously in music clubs.

That experience was an experience that never forget in my life because I was seated at very near field due that where is seated my system have good size for lsten my ystem but to litltle for a drum batery. The cymbals and the foot big drum are something to hear: dynamic is in other world even that he was not playing at live SPL.

He likes a lot    how pwerforms my room system at 95db SPL with peaks at 106dbs SPL. Obviously it like to me a lot and as he the bass range sounded just riht with the right foundation for all the FR range in the LP we are listening: astonishing, for say the least.

Now, from where comes this kind of marvelous high quality performance becaus eit is not that my system bee/be oriented to that bass range but is with very good balance.

More or less the last 5 years I was fine tuning here and there the system and that fine tuning means to modified what like me the more what goes more for my taste?.NO, my taste is out of my room/system fine tunning, certainly I have a test comparison wide and bulet proof whole proccess where I use the same 15-20 track P recordings and a few CD tracks too, obviously I know all those tracks better than the fingers of my hands.

What I was testing ( with test recordings ) is to look and measures ( where I can or I know how to measure) that everykind of distortions/resonances/noises developed for each one link in my room/system chain stay at minimum: this is the target and I'm not looking if I like or goes to my taste because this is not the main issue,

What I did it in my system can do it in any system with price no object systems or low/moderated ones, this is not important becaus e what I want o achieve are those distotion/resonsce/noise levels at minimum that those system links permit it.

In any case what we will listen through any of those kind of systems and with any kind of MUSIC will be truly satisfactory and enjoyable. There is no " land " to mistakes ".

As higher the resoluituion of the room system as more easy is to detect the system " errors " and from where came to fix it

Nothing of all those has to do with the taste of any system owner if this system owner knows how to do it.

Yes, we have to have wide first hand experiences every kind along a healthy knowledge level and skills to do it and comparisons are not only through your sstem but along other home audio systems of every kind with ay kind of LP recordings and digital recording too and of course attend to as many we can live MUSIC events to have a " guide ".

 

Even with all those nothing is perfect because one thing is to put those whole colorations at minimum and other thing is to say that already gone because never really gone, always are there but " voila " we just can's be aware of it after that fine extensive tunning excersice.

One-two of those test tracks are  80's recording 33rpm single mix ( one score per side ): Byllie  Ocean Caribbean Queen or the 45rpm 12" FUN FUN Color My Love.

With these two tracks I can test any system and tell is something is wrong or corect down there from the very first minutes that I listen these recordings. In around 15 minutes I can do a fast system quality performace idea, any sysem and no matter what.

It's the same when you are  a drumer player you can with out see if those cymbals are Sabian or Zildjan and you will know in " seconds ". Almost same with what I'm trained to in a room audio system.

Nothing of those is a matter of taste.

R.

Dear @colossalsound  : I dont know if @kennyc  knows why existe the SUT, the true behind SUT. I already explained in this forum at least 5 or 6 times in the last 10 years, so I don't repeat again.

Ypsilon, why  if for you so good SUT whe is FR is a -3db 8hz to 60/70khz, heavy limitation down there to say the least.

Next information could help any one to understand about SUT role with LOMC cartridges:

 

" Some of you may find that I’m using some inappropriate terms. The aim of this paper is to understand the way step-up transformers function, and the rules you should follow to select the appropriate step-up to use with your MC cartridge (if you want to obtain a happy marriage).

The characteristics you should take care of for this kind of cartridge to be correctly exploited by your system are:

  • The output level, measured in millivolts
  • The internal impedance, measured in ohms
  • The load impedance, measured in ohms too

In this paper, we’ll ignore high output MC cartridges that can be used with a MM input and concentrate on MC cartridges with an output of less than 1 mV. (The output level of MM cartridges is between 2.5 and 7 mV).

The job of a step-up transformer is to raise the output of the MC cartridge in order for that output to be correctly handled by a MM phono section. At the same time, the step-up transformer adapts the impedance of the signal produced by the MC cartridge to an impedance that can be “read” by your MM input. You must understand that step-ups all have different characteristics that we’re about to explore. These characteristics are such that if you select a step-up and a MC cartridge at random, your probability of obtaining a happy marriage is close to zero.

So please, don't make a definitive judgment of a step-up or a MC cartridge. Before saying “this step-up is pure BS” or ”this cartridge is pure BS”, check the compatibility of your MC / step-up combo. Most of the time, if the sound isn't good it’s because of a compatibility problem.

So, you need to amplify the signal output from a MC cartridge? In fact, you use can two different kind of devices to do that job:

active devices : head amplifier of MC section on a phono section

passive devices : step-up

How can you tell that a device is active or passive? Very simple, on active devices, there is a plug! On step-up, no plug (so, it’s passive since there is no power supply).

Another difference, that makes things unclear for a newbie, is that on active devices the load impedance is indicated (100 ohms, for instance), on passive devices you don’t have a load impedance but an internal impedance; rather than a manufacturer giving a load impedance figure you will get a statement such as: “this step-up is designed for use with cartridges with an internal impedance of 40 ohms". We’ll ignore active devices. There is no fun there; cartridge manufacturers generally specify a load impedance, so you set up your active device (head amp, MC phono section) to that load impedance and listen; game over. 

By reading this paper you will find that some cartridges cannot be used with a step-up, whatever its characteristics. For these cartridges you’ll have to use an active device.

Now, on a step-up you’ll find internal impedances indicated: for instance, take a look at a DENON AU320, two positions are possible: 3 ohms and 40 ohms. So this step-up should be good with cartridges of internal impedance of 3 ohms and 40 ohms. Now the problem is, that for the moment, the load impedance used in that step-up is not known (but we’ll soon know this very important information!). We’re only sure that this load impedance is superior to the internal impedance. And secondly, the load impedance given by a manufacturer for its cartridge is the one you should use on active devices; the one you should use on passive devices is not generally the same and is superior to the load impedance given by the manufacturer.

How can you tell that the impedance indicated on a step-up is not the load impedance?

Let’s do some calculus! If a step-up has a gain of say 1:10, this means that the output of the cartridge will be multiplied by 10. If the output out of the cartridge is 0.3 mV, you’ll have, after the step-up, 3 mV, perfect for a MM input. Now, your MM input has its own impedance generally equal to 47 Kohms. The signal emitted by the MC cartridge must be in accordance to that 47 Kohms. A step-up modifies the impedance of the output by a factor equal to the square of the amplification ratio. This is known as ‘natural impedance’. A word of caution: by itself, a step-up doesn’t have any impedance. The natural impedance is directly linked to the impedance of your MM entry and to the amplification ratio.

So, a step-up with an amplification ratio of 10 has a natural impedance and load impedance of 470 ohms (if your MM input impedance is 47 kohms: 470=47000/10²). Now, let’s go back to our DENON AU320: on the 40 ohms position, since the amplification ratio is 1:10, the load impedance is 470 ohms.

You’re not convinced? Let’s do more calculus. If your load impedance was 40 ohms, your amplification ratio, in that case should be equal to (47000/40)^0.5 = 34.3. With a cartridge output of 0.3 mV, you are sending 0.3*34.3 = 10.28 mV to your MM input. This is important; you may be overloading your MM input. Let’s do the same calculus on the 3 ohms setting. If it were your load impedance, the gain in that case should be (47000/3)^0.5=125.16. Again, with a 0.3 mV output cartridge, you’re about to send 37.5 mV in your MM input: this IS overload! A MM input is generally designed to accept an output between say 2.5 and 10 mV, not 37.5 mV! And the amplification ratios calculated here have nothing in common with the step-up specs given by manufacturers (as we’ll see in a few moments).

So, for one channel, there are two coils: a primary (the ‘input’: the signal emitted by the cartridge arrives at this one) and a secondary (the ‘ouput’: the amplified signal will go out to your MM amplifier stage from this one). You will see that there are less turns on the secondary than on the primary. This is not a strange idea from the designer of this scheme. Your amplification ratio is a direct result of the turns ratio (primary/secondary) (ok, I know, I know, a perfect transformer doesn’t exist and things are not that simple but the rule indicated here is a good proxy). This explains why, on a step-up that can be used with several internal impedances cartridges, the gain differs according to the internal impedance you’re selecting. On the audio technica step-up represented by the scheme, the gains are 23, 26 and 34 db for respective internal impedances of 40, 20 and 3 ohms.        

In a perfect transformer: N2/N1 = V2/V1 = x

Where: N2(1) : number of turns of the secondary (primary)
V2(1) : output out of the step-up (in)
x : amplification ratio
And Z2/Z1 = N2²/N1² = x²
Where: Z2(1): impedance of the secondary (primary)

Another « detail »: the grounding of the step-up. This is very important. If you’re having grounding problems, or shielding problems, you’ll probably have “hum”.

But, why are only internal impedances indicated on a step-up?

The main reason is certainly the fact that, as I already indicate, natural impedances are not constant: they are a function of the impedance of your MM input. For instance, if your MM input has a 10 Kohms impedance, with a 1:10 amplification ratio step-up, the natural impedance (and your load impedance) is 100 ohms (10000/10^2).

What step-up for my cartridge?

This is THE question. If you’re looking for a step-up you can buy second hand step-up transformers, brand new (most Mc cartridge manufacturers produce step-up transformers) or build them yourself using parts from manufacturers like Lundhal, Sowtek, Hashimoto, Jensen.. (See links to those manufacturers at the end of this paper).

To make things clearer, we’re going to take a look at the specifications of available products. Why? Because these products were designed by MC manufacturers, let’s assume that they knew what they where doing.  Specs shown here are compiled from various sources (internet or vinylengine inmates like Yosh (Hi Yosh!). if you have data relating to other products, contact me and I’ll add them to the table. All I need to know is the gain (measured in db or in amplification factor 1:x)  and the recommended internal impedance of the cartridges to use with that step-up.

Data in bold type are manufacturers specs, other data was recalculated this way:

X factor = 10^[(gain in db)/20]
Gain in db = 20*ln(x factor)/ln(10)
Natural impedance = 47000/[(x factor)^2]

Manufacturer Model Gain in db x factor Natural impedance Recommended Impedance
Ortofon T5 26 20,0 118,1 3-40 ohms
  T10 32 39,8 29,7 2-4 ohms
  T10 MK2 28 25,1 74,5 2-6 ohms
  T20 32 39,8 29,7 2-4 ohms
  T20MKII 28 25,1 74,5 2-6 ohms
  T30 20 10,0 470,0 24-48 ohms*
    29 28,2 59,2 6-12 ohms*
    32 39,8 29,7 5
  SPU-T100 26 20,0 118,1 1-6 ohms
  T1000 26 20,0 118,1 2-6 ohms
  T2000 35 56,2 14,9 3
  T3000 30 31,6 47,0 2-10 ohms
Fidelity Research FRT-4 31 35,5 37,3 3
    26 20,0 118,1 10
    25 17,8 148,6 30
    20 10,0 470,0 100
  FR XF-1 30 31,6 47,0 4-18 ohms
  FRT-3 26 20,0 118,1 30
    31 35,5 37,3 10
  XG5 34 50,1 18,7 < 3 ohms
    26 20,0 118,1 3-18 ohms
    22 12,6 296,5 18-40
  X1-M 30 31,6 47,0 4-18 ohms
  X1-H 25 17,8 148,6 19-40 ohms
  X1-L 36 63,1 11,8 3
Denon AU 320 31,1 36 36 3
    20,0 10 470 40
  AU 340 30,4 33 43 3
    20,0 10 470 40
  AU310 20,0 10 470 40
  AUS1 22,3 13 278 3-40 ohms
  AU300LC 20,0 10 470 40
Audio Technica AT700T 34 50,1 18,7 3
    26 20,0 118,1 20
    23 14,1 235,6 40
EAR MC4 29,5 30 52,2 3
    27,6 24 81,6 6
    25,1 18 145,1 12
    20,0 10 470,0 40
  MC3 29,5 30 52 4
    26,0 20 118 12
    20,0 10 470 40
Supex SDT 3300 28,5 26,6 66,4 2-10 ohms
Bryston TF1 22,5 13,3 264,3 5-35 ohms
    16,5 6,7 1052,2 40-250 ohms
Rothwell rothwell 22,0 12,6 296,5 < 40 ohms
Nakamichi MCB100 26,0 20 117,5 2-20 ohms
Sony HA-T110 26 20 117,5 3 - 40 ohms

* ortofon T30 : the natural impedance is certainly used for 48 and 12 ohms position and is reduced by “resistor tuning” – if someone here can read the value of the resistors inside the T30, that could help us a lot!

Part 2

What is there to understand here?

Let’s imagine I have a 3 ohms internal impedance cartridge. What are the devices I should buy?

Some devices from this table have a 3 ohms setting: FRT-4, Denon AU 320, Denon AU 340, AT700T, Ortofon T2000, FR-X1L, EAR MC4. What we can see is that the natural impedance of these devices (respectively 37,3 - 36 - 43 - 18,7 – 14.9 – 11.8 and 52,2 ohms) can be separated in two groups: Some of them have very low natural impedance (between 11.8 and 18.7 ohms). I think these figures are really too low and will limit this kind of step-up for use with very low internal impedance cartridges (1-2 ohms) especially the Ortofon T 2000. The remaining step-ups have a natural impedance between 36 and 52.2 ohms.

We will consider this range as a good range for loading a 3 ohms internal impedance MC cartridge. The amplification ratios associated with these step-ups are between 30 and 36 (gain is between 29.5 and 31 db).

Now, there are some other step-ups in my table that have a natural impedance between 36 and 52 ohms:  EAR MC3 (4 ohms position), Ortofon T3000 (2-10 ohms position), FR XF-1 (4-18 ohms position),  FR X1-M (4-18 ohms position), FRT-3 (10 ohms position). Conclusion: you can use that step-up at the position indicated with your 3 ohms cartridge. 

One could add to this list the Ortofon T10, T20 and T30. The natural impedance is equal to 30 ohms (a little low for me – I would couple those transformers with very low impedance cartridges of say 1 - 2 ohms). On one hand you could say “come one, this is Ortofon, worldwide specialist of low impedance cartridges, they know what they doing”. But on the other hand I must add a very important point to understand why Ortofon may have changed their minds. These models are rather old (70’s 80’s). It seems that manufacturers realised in the 80’s that designing a high gain step-up transformer is really difficult. The more gain you have, the more difficult it is to have a flat frequency response. The difficulty of producing a quality high gain step-up with a linear response is translated in the actual price of these step-ups: for instance, the price of an Ortofon T3000 is 1625 euros (are you sure you really want to buy a low impedance cartridge?)

But, from this table, you can find some other transformers that are said to treat correctly a 3 ohms internal impedance cartridge. In fact, for these transformers, manufacturers provide a range of possible internal impedances for the transformers.  

Things are now a little more complicated and one could ask if we can really trust the manufacturers’ recommendations? Let’s take a look at the Denon AUS1, Ortofon SPU-T100, Ortofon T1000, FR XG5, Ortofon T5, Nakamichi MCB100, Sony HA-T110, Ortofon T20MKII, Ortofon T10 MK2 and Supex SDT 3300.

The natural impedance for these transformers is between 66.4 ohms (Supex SDT 3300) and 278 ohms (Denon AUS-1) : there must be a problem for the Denon unit. A 3 ohms internal cartridge plugged into a Denon AUS-1 is certainly producing very amplified highs. So, when a range is indicated for your step-up, there is always some kind of compromise since they cannot be good everywhere. The risk is to have a too high a load impedance for a cartridge with an internal impedance equal to the minimum of the range (too bright sounding) or too low a load impedance for a cartridge with an internal impedance equal to the maximum of the range (no high frequencies in this case).

The Denon AUS-1 should work well with a 40 ohms internal impedance cartridge but no good with a 3 ohms internal impedance cartridge. The Ortofon T5 might not work very well with a 40 ohms internal impedance cartridge or a 3 ohms internal impedance cartridge, but may be good with say, a 10 ohms internal impedance cartridge.   Let’s take a look now at what is proposed for 40 ohms internal impedance cartridges: there is a consensus on a natural impedance of 470 ohms (biased by the fact that we’re having a lot of Denon products in the table). Now, from the table, you can see that the FRT-4 (100 ohms position) and the Ortofon T30 (48 ohms position) will give you the same natural impedance. With transformers proposing a range of internal impedance including 40 ohms, the natural impedance is generally lower, from 118 ohms (Sony HA-T110, Ortofon T5) to 296 ohms (FR XG-5) – for the Briston TF1, 40 ohms is the minimum of the range : the natural impedance (and then the load impedance) is much to high (1052 ohms).

Let’s assume that the loading of a MC cartridge with a transformer is not an exact science.

Loading a MC cartridge is not an exact science? Why? Simply because manufacturers never produce a unique load impedance for a given internal impedance and because, for a given natural impedance, there is frequently a range of internal impedances that suit the transformer. Now, for a given internal impedance, we should propose a range of load impedance. What I’m proposing now is just a starting point – by following my rules, I’m not telling you that you will obtain the perfect load impedance, I’m just telling you that you won’t make stupid mistakes.

So please, don’t contact me to insult me about my rule!

For this rule, we’ll use a spec given by the manufacturer: the load impedance. We’ll take this load impedance as meaning a load impedance recommended for active transformers (and not for passive devices). This data certainly includes things relavent to important characteristics of the cartridge we don’t know, but that must be considered.

A manufacturer generally gives you a minimum load impedance for active devices (or a range, but it’s less common).

If the load impedance (for active devices) is said to be > or equal to 20 ohms, the internal impedance is 3 ohms, you should try to load your cartridge at load impedances between:

  1. the load impedance given by the manufacturer (20 ohms)
  2. the load impedance given by the manufacturer + 10*internal impedance (50 ohms)

Now, for a 40 ohms internal impedance cartridge with load impedance for active devices of 100 ohms, you should try load impedances between 100 and 500 ohms. If your system is too bright (suppose you’re having triangle loudspeakers…), you will certainly be happy with something that will “cool down” your sound, so try something close to 100 ohms. On the contrary, you may be happier with something closer to 500 ohms.

Now, my opinion: I never hear satisfactory results when the load impedance on a passive device is equal to the load impedance indicated by the manufacturer (we understand as load impedance on an active device). You’ll try and you’ll tell me. We’ll see later the way to test different load impedances but you don’t need to test 100 values between 100 and 500 ohms : something like 3 or 4 value is enough and in our case, you could try 100 ohms (and you’ll tell me), 200 ohms, 300 ohms and 470 ohms (with a 1:10 transformer).

If the manufacturer is proposing a range of load impedance (say between 20 and 200 ohms), follow that range by testing say, 50 ohms, 100 ohms and 150 ohms.   

Do you think things are over? No, they aren’t! The load impedance is an important thing BUT it’s only the first important thing to consider. Remember that the natural impedance is directly linked to the gain of your step-up. In the next table, you will see the maximum gain of your step-up to have a desired load impedance.  "

 

The information is to long but suffice is to say that each model of LOMC cartridge needs a DEDICATED SUT for that cartridge to works fine. This is another huge limitation of the SUT otherthat is limited FR range at both frequncy extremes.

 

ASs I said the best SUT is not SUT. It does not matters system price or owner kind of money because exist active high gain units for any owner level of money .

 

R.