What constitutes a "high output" moving coil cart?


Lately I've been delving into different MM carts on my mid fi rig, and am itching to try a moving coil type. My phono pre limits my choices to "high output", so I am wondering if there is a sort of "dividing line" between low and high output, in terms of mVs. Thanks in advance for any thoughts.
Depends on your overall system gain, intrinsic noise floor of your electronics, typical listening level, etc. Basically LO MC is generally considered to be <0.3 mV. Most MMs deliver about 4-5 mV, I think. Many HO MC carts are spec'ed at 1.5 to 3 or 4 mV. There is a cartridge calculator at the KAB web site that will let you see the relationship between the parameters. If you have a smaller room, high pre-amp or amp gain, and/or listen at low levels, you may even be able to get into a MO MC cart.
All I can tell you is that I use a phono pre for MM or "HO MC" and my HO MC cart yields 2.5 mV. It has plenty of gain if that is any help.
I have found most HOMC cartridges specify a 2.5mV output and that makes them compatible with most MM input sections on a preamp. My Blackbird is in this category and works very well in my system through the MM input on my VAC preamp. Below this output a SUT or Head Amp could be required if you do not have a MC input in your preamp. There are a couple of lower rated cartridges (the Denon DL110 and Denon DL160 in my experience) that are rated at 1.6mV, but operated fine through my MM input. I had read that they actually put out a higher voltage than their specifications stated.
With no music playing, set your volume control to the highest position that you would normally set it at with the MM cartridges you have used. Then see how much higher you can turn it before the hiss level at the listening position becomes objectionable.

Let us know what those two settings are, in terms of clock-face positions (e.g., 12 o'clock, 3 o'clock etc). Assuming that the first of those two settings lies at or above the 12 o'clock position, if you can rotate the control perhaps 45 to 60 degrees or so higher before the hiss level becomes objectionable, and without running up against the top of the volume control's range, I suspect that you would be good to go, in terms of noise performance and gain, with any HOMC, down to perhaps 1 or 1.5 mv. If the first of those two settings lies significantly below the 12 o'clock position, a somewhat smaller amount of rotation would be equally good, as volume control adjustments become increasingly coarse at lower settings.

The smaller the difference between those two volume control positions, the closer you would want the HOMC's rated output level to be to the rated output levels of your MM's.

If you have access to a sound pressure level meter, all of this could be figured much more precisely.

Keep in mind, however, that there are issues of mechanical compatibility between cartridge and tonearm that have to be considered as well, particularly the relation between cartridge compliance and tonearm effective mass. Google those terms and you'll find lots of additional information.

-- Al
The "highest" of the "LOW output" moving coil cartridges have an output of about 0.7mV maximum -- that's seven tenths of a microvolt! Whereas the "lowest" of the "HIGH output" moving coil cartridges have, as noted above, a minimum of 2. mV AT LEAST; which is roughly three times that of the highest output of the low output (standard) moving coils.

And further, it should be noted that high output moving coil cartridges are really offered as a convenience for people who hope to obtain the 'magic' of a moving coil, but using the moving magnet input of a receiver or integrated amp. The problem is that high output moving coil cartridges really can't provide that 'magic' -- because in order to obtain a high output, they must have coils with many, MANY times the windings of 'regular' moving coils; and with such a heavy coil, their transient response is nothing like that of a 'real' low output moving coil.

In my opinion, there are many moving magnet and moving iron cartridges that out-class most of the high ouput moving coils (and some low output moving coils too!) and would be a much better (sonic) choice than a HOMC, if it's simply that a person just doesn't want to mess with (or pay for) an outboard MC phono amplifier or step-up transformer -- mandatory hardware if one wants to "do moving coil right", since most preamps or receivers only provide for MM cartridges, if they even have phonostages.
High output means exactly that - high. That's, there is a lot of it, of the output.
Many thanks to all for the great responses. In particular:

"In my opinion, there are many moving magnet and moving iron cartridges that out-class most of the high ouput moving coils (and some low output moving coils too!) and would be a much better (sonic) choice than a HOMC..."

To me this is fascinating. Would you care to share any examples? Thanks again -

Nsgarch is exactly correct, unless you will be considering the multi-thousand $ MC's, there are many fine MM's that are worth considering. Some would argue that EVEN IF you will be considering top tier MC's, you should consider a MM. Read this and learn :-)


Another very important point to consider, which further supports the MM
route: In my experience, most preamps' MM section sound better (cleaner/simpler signal path) than their respective MC stage. Having said all that, if yours can accommodate (and you can afford) something like the Benz M2 MC, and you like/prefer the sound of a good MC, that is also a viable alternative. Good luck.
Thank you Frogman - very useful.

Lets not forget that some of the high output moving irons claim to have stylus assemblies that are even lighter than the exotic LOMC's. Grado and Soundsmith come to mind.
Dear Rbloom659: As already Nsgarch/Frogman posted the HOMC unfortunatelly IMHO is the " worst " alternative against either LOMC one or the MM/MI alternative.

The Clearaudio Virtuoso Wood is a very good option and seems to me that in your system you will enjoy it a lot over what you have today or what any HOMC could shows you. The Hifiharv advise is a good one too.

Regards and enjoy the music,
It is important to find out where your phone stage starts getting noisy. If the cartridges output is too low, any benefits of the HOMC will just be lost. Everyone will react different. Every person has their own taste also.

In the '70s or '80s, they had a 4 channel LP system called CD4. Those cartridge had a higher limit to their frequency response. They came out with a new stylus shape around that time also. I remember giving it a try, and it was the worst investment for myself. I bought the Audio Technica CD4 compatible, the Empire 4000 series, and possibly another brand, to run this new 4 channel LP. Everything ended up being a waste for me. I even tried these in my other turntables, friends tried them, and they didn't want them either. They may be in the closet yet, as it couldn't be all the different turntable, arm, phono stage combination's mismatch. Others thought these cartridges were great.

So making sure the cartridge gets along with the arm, and preamp is important. The way it sounds is just someone else's opinion. I use all three of these types. They all could sound great, or poor.
I third what Nsgarch wrote regarding HOMCs vs the best of the MM and MI variety.
There are some HOMC cartridges that put out more than I imagined. I guess the are some cartridges that will output around 1mV that I've heard that sound good. Those may not work with a lot of MM phono preamps. Some of those would fit in the med-high output category. If your still using the Goldring 2200, that looks like it puts out 6.5mV. That's 6 times more than what I had in mind.

The biggest compromise of the group would be to use a to low of an output cartridge for your phono amp IMO. The Audible Illusion link is just to see how much they (cartridges) do vary, only. Some links to look at.[http://www.musicdirect.com/p-3733-goldring-2200-mm-cartridge.aspx][http://www.kabusa.com/pregain.htm] [http://www.audibleillusions.com/technical/bulletin2.htm]
The KAB link is what Swampwalker was referring to, I think.
Wow all this negativity towards HOMCs. I really like my Dynevector 20X HO into a Graham Slee Amp 2SE. I think it sounds much more detailed and dynamic than my MM Goldring cart for instance. I am not an analog nut and don't switch tables, arms and carts very often I should add. I still want to say that I am very satisfied with my HOMC it sounds great to me and I do keep company with analog nuts with "real" low MCs.
Mechans, please don't feel we're 'dissing' HOMC cartridges across the board. For example, the Decca line of HOMC cartridges has been almost a cult favorite for decades, but it's mechanism is totally unique to that cartridge, and doesn't suffer the high inertial mass characteristic of the coils of typical HOMC cartridges. And new wire-making techniques combined with ultralight metals and coil cores have enabled some manufacturers to keep the inertial mass down. But there are still (unavoidable) issues like higher inductance (magnetic 'lag') when coil windings increase. So you see, there were/are reasons why the best MC carts remain low output.

I'm not surprised your 20X sounds better than the Goldring, but they're not in the same league, and so those results don't really tell us anything ;--) If you decide to upgrade your cartridge one day, I would recommend (based on your self description) that you keep you gear simple as it is now, and check out some of the finer MM/MI cartridges out there.

Remember, Joe Grado invented the moving coil cartridge -- but decided not to manufacture them in favor of moving iron designs. Now, that doesn't mean (as some people have assumed) that he thought MC's weren't good reproducers; but his philosophy was always about his products providing the best sonics per dollar (and himself the most profit ;--), and felt he could achieve both with the moving iron designs. Judging by the age and success of his company, he seems to have been right!