Low output MC and High output MC, why the discrepancies??

I am in the process of looking for a new MC Cartridge. Since I use the phono stage that is built into my CAT preamp, the ultra low output MC are persona non gratis
So... I am looking for a medium output MC...around 0.4 mvolts and above....ANY suggestions.

BUT, what I don't really understand is why the manufacturers of some of the "better" MC's are building the cartridges with outputs of 0.2mv's or sometimes even less!! Surely, the harder the phono stage has to work, the more chance for a) failure of the phono stage, b) increased heat and c) more background noise...

What am I missing here??

 

This is probably the biggest issue, but as we are in the modern era of solid state devices, a competent designer can minimize noise from a gain stage. I can't answer your question of low output.

jeff

 

Low output MC carts have small coils with few turns, therefore lower mass and lower impedance.

Either a transformer or a high gain stage is used at the receiving end.

 

yes to Burt's post

 

It seems like higher output MC (~ 0.5 mv) and very low internal impedance is starting to get more popular. For example Lyra, My Sonic Lab, Air Tight and new TechDas.

 

What I meant to say was , I couldn't answer "why" manufactures choose a very low output, vs a typical output of say .4mv.

jeff

 

Exactly my question. Agreed that higher output and lower impedance is gaining popularity...BUT seems to still be in the minority. As an example, I was considering the new Transfiguration Proteus...until I realized the output was basically minuscule...WHY???

 

Probably because they want to design something with lower mass and lower inductance for whatever sonic or design benefits the designers think that gives them, and they figure today's electronics are up to the task of providing enough gain.

To your original point, I don't think there's any greater risk of failure for a modern phono pre with enough gain for a 0.2 mV cart vs one for a 0.4 mV cart; noise, yeah, though in truth with today's phono stages that can provide like 60-65 dB of gain with a -88 dB noise floor, well, the self noise from the preamp is probably below the level of vinyl woosh, tone arm ringing, and surface noise from typical vinyl playback. And with the abundance of excellent SUT out there, even if you have a phono stage with less gain on tap doesn't have to require getting a new preamp if you want to use a very low output MC.

 

Good question. In theory there are good reasons but in practice the benefits are probably not realized.

1) You can use non ferrous (air) cores for less distortion.

2) Lower moving mass for better tracking.

3) lower impedance in the generating system pushes the resonance effects further above the audible band. Gives less phase shift to the upper frequencies.

1 and 3 will probably be lost with most step up transformers. 2 is dominated by tip mass with diamond and cantilever mass being the biggest factors.

 

Chervokas, that may be correct. However, i don't see the value of inserting a SUT into the chain. IMO, it would likely subtract from the overall SQ, due in no small part from the fact that there is now another component in the chain.
Therefore, any perceived or actual increases that one might gain from having smaller coils with less turns at the cartridge would be off- set by the insertion of a SUT. Since I have a phono stage with slightly less gain on tap...although I'm not so sure about this, although I do know that the tubes get noisier as the gain goes beyond their comfort level.( Which I suspect is the case with all tube phono stages---- and probably most, if not all, ss phono stages ( an increase in noise as the amplification rises)). The question therefore still remains....why not increase the output of the cartridge while at the same time decrease the impedance?

 

You've basically got two choices (three if you include tubes) for step up, transformers or transistors. Tubes are going to be biggest challenge, because of noise, and there are other issues. There are commercial phono stages that have SUT's "built in" for the extra gain needed for LOMC's. Nobody seems to be compaining, so what gives?

jeff

 

You aren't wrong. Every single SUT I have heard lowered transparency and resolution. I just can't see the point of having that large amount of wire trying to step up an extremely tiny voltage. The best phono stage I've heard used a very high gain triode (with a solid state CCS load) in the first gain stage.

 

Jeff, I am simply noting that IF one doesn't have a very high gain phono stage, or is using a tube phono stage ( like me); then the selection of passable cartridges is less extensive than one might think. Due, to the fact that there are still a lot of cartridge manufacturer's who are producing ultra low output cartridges. ( which I am trying to understand the reason for).

 

I'm using my Denon DL-103R at the moment ( I have other LOMC's), which has an advertised output of .25mV. I've never had an issue regarding gain, and I've had friend's tube based phono stages in my system, as well as my SS daily driver preamp. I've got a choice of SUT with a 20:1 winding, or a SS step-up with 12,20,26dB gain settings. With the 103R, all I need is 12dB gain before my phono. I do use a tube based line stage with about 15dB gain thou.

jeff

 

The only one I have experience with is the VDH MC One Super, 0.6mV. It has a fairly neutral response and a world class tip. I have an original MC One but it was rebuilt to "Super"specs. A lot of other cartridges in this range have a rising top end so buyer be ware. Benz and DV may be worth looking into. If you like a bit of top end sparkle there are a lot more.

Those ultra low output moving coils are pushing the envelope of performance. They should provide the cleanest source signal available. The problem is preserving the integrity of the minuscule signal.

 

To increase the output voltage of the cartridge you have to add more turns of wire to the cartridges coils, that's also going to increase the inductance and the output impedance. It's just an unavoidable byproduct of adding more turns of wire the coils. So if you want higher output you're also going to have higher mass, higher impedance, higher inductance.

I'm not saying one or the other approach is better -- higher output/higher inductance carts, or lower output MC's with SUT's or higher gain phono stages, etc. All have their advantages and disadvantages. Personally I happen to like SUTs because you can get lots of voltage gain with none of the thermal noise you get using active devices for gain, but of course you want low loss transformers, you need to take care in terms of the reflected impedance the cartridge sees, you need to keep the capacitance of the phono stage and the cables between the SUT and the phono stage extremely low, etc.

I'm just saying to this question of why cartridge designers build very low output MCs -- they must believe that there are sonic advantages that result from the lower mass, impedance and inductance.

 

For these cartridges I would get something solid state like Pass Labs or Klyne. I've heard an XOno play dead quiet with even a 0.15 mv cartridge.

 

David Fletcher's much-loved Talisman Alchemist from the late '80s took a very different approach to the problem of low output vs. high output. To overcome the perceived negatives of a high output MC, the Alchemist used what he called "intensified focus" to increase the output to a healthy 2mv (instead of the regular Talisman's .26mv). I've owned both versions, I can tell you there's very little difference.

For more detailed info, search Sumiko Talisman Alchemist on vinylengine.

Happy trails,
Larry B.

 

Actually, it is the other way around in my understanding. We have the ability to amplify as much as needed with little issue. The harder thing is recovering a physical movement and transforming it into an accurate electric facsimile and than as Burt, so clearly delineated, the hard work is done by a cartridge and low output MC can often do a more articulate job of it due to their more nimble motor architecture.

 

I happen to have a 0.3 mV output cartridge. I was a bit concerned at first but I have a very low noise SS phono preamp with 65 dB of gain and it works just fine. Though I do have to turn up my line preamp volume control a ways for phono input compared to other sources, I hear no detriments at all.

 

I think that IF the phono preamp cannot cleanly amplify the signal coming from the cartridge, it makes no difference how articulate the cartridge may be. Do we really have the ability to amplify the signal from the cartridge with little issue and with as much amplification as we need?? I guess it may come down to how we perceive the quality of that amplification. IMHO, a tube phono preamp is my preferred component in this situation.

 

At my home, the phonostage is working just fine... And I imagine we could ascertain that IF you don't pay your electric bill it won't matter how accurate your cart is or how well your phonostage amplifies... I don't understand your point.

Well I don't know, maybe we should ask Aesthetix, Ypsilon, Kondo, Sutherland, Bolder, Jolida, Graham, Pass Labs, IF we really have the ability to amplify a cart.

I would assert that regardless of what we perceive to be quality there is no good theoretical argument to question whether we are capable of amplification. If what you really intended to suggest is that you find my logic faulty and that phonostage amplification may be a more difficult task than phono cartridge pick-up IYHO, I'm afraid I still do not agree, but at least you may be able to draw on some interesting points to at very least claim that both are very difficult to do well.

A valve phonostage is my preferred component as well, although there is much to like in many of the solidstate units offered today as well. Everything has its strengths and trade-offs IMHO.

Welcome, Happy Listening!

 

However, while we can say that a phono stage is working "cleanly", IME the harder said phono stage has to work, the more likely it will introduce distortion. Saying we are capable of amplification is moot...the question I am posing is how "clean" that amplification is. With a cartridge that puts out a minuscule output...( which brings up the question as to what is "minuscule"...to some it's 0.2 mvolts, perhaps to others it's 0.002 mvolts!); the likelihood that the phono stage is distorting would seem to me to increase as the output from the cartridge decreases. Therefore, my question as to why not attempt to build a cartridge that has a higher output and with lower impedance? ( I'm fairly certain this can be and has been done); instead of more and more ultra low output models.

 

The second post here really tries to explain; http://www.audiocircle.com/index.php?topic=102952.0

 

Based on your theoretical, if I follow, so the harder the "whatever" has to work in a given system, the less chance the "whatever" will succeed and the greater likelihood it will introduce distortion. I don't see an obvious solution here.

"Clean" is what, a S/N spec that would be your driving factor? How clean do you need it to be? I offered a list of exemplary high gain phonostages that may well set the standard for state of the art today. I have heard product from each and every one of them and their designs and application fall far from moot. Do you care to reformulate you question, again?

Ok others, name a phono cartridge that has a 0.002 mvolts output, I'm unaware of that particular cart.

Yes, there are plenty of highly regarded cartridges that are of a higher output nature on the market today, some MM, Mi, and even MC, so if you believe that the phonostage has the more challenging task, help yourself.

Further up, Chervokas gave a pretty straight forward explanation of how current cartridge design follows with the laws of physics.

Happy Listening!