MC & MM cartridge difference


i am new to this hobby so sorry if this is elementary info but what is the difference between moving coil and moving magnet cartridges? Also what results will be gained or lost when using a preamp recommended for one type and using the other?

thanks for any info or links offered.

dave
timewasjustajoke
Most importantly, the MC carts have much lower output voltage than the MM types. Typically about 1/10th. Hence, you need 20dB more in phonostage gain.

Common values are phono gain of 40dB for MM and 60dB for MC. This can vary a bit. There are even "high output" MCs that have output signals similar to MM.

jh
In addition, all MM cartridges are designed for a phono input impedance of 47K ohms, which is what virtually all MM phono inputs have. OTOH, the optimal input impedance for MC cartridges varies widely.

High output MC's of the type mentioned by Hagtech are designed to work with the limited gain of a MM phono stage, so they're designed to work well into 47K too.

Medium and (especially) low output MC's that need more gain almost always need a lower impedance too. A few really low output MC's (.1mv or so) need an input impedance of just 2-3 ohms and a ton of gain too - at least 70db.

Since the gain and input impedance requirements of MC cartridges varies widely, careful matching between MC cartridge and phono stage becomes vital. Few dealers have the knowledge to do this properly any more. More than a few phono stage manufacturers don't understand it any better. This can come as quite a shock when you buy an umpti-thousand dollar phono stage, an umpti-thousand dollar cartridge and discover they don't mate well.

Hagtech knows all this, better than me, and his phono stage matching advice is always sound. I suspect he didn't want to scare you with too much, too soon. I'm not so nice! ;-)

Doug
Does the higher preamp gain result in a noiser background for the MC compared to the MM?
Dear Dave: Other than with other people posted an important difference is IMHO an unjustified very high price of the MC cartridges against the " low " one in MM cartridges.

Along with all those subjects is the kind of tonearm that usually needs MC and MM cartridges: low to medium mass the MM and medium to high mass the MC cartridges.

Other critical subject is that normally ( 90-95% ) the MC phono stages out there use step-up transformers to achieve the gain for the MC cartridges, this step-up transformers always make a heavy degradation to the cartridge signal: stay away from it.
The MM cartridges does not need any step up transformer, this is an advantage.

Regards and enjoy the music.
Raul.
Does the higher preamp gain result in a noiser background for the MC compared to the MM?
Unless the MC stage is a very good one, that is a possibility. The trade off is the greater responsiveness and subtlety of the lower output MC's vs. the higher output MM's and MC's.

Raul's point that MM's can be very satisfying is a good one, which he can make with authority since he owns more fine MC's than most of us own socks. Which type you'd enjoy more would depend on the kind of music you like and your sonic priorities. Since you're asking fairly basic questions, it's a fair bet you haven't fully expolored your sonic priorities, yet. Hearing different equipment types, if you can, is educational for both your audio brain and your ears. Educating them should be one of your higher priorities. Chasing different equipment without understanding your sonic goals can be fun, but it can also get very expensive.
Thanks for all the reply's and great info. This hobby has become quite a obsession for me and I look forward to experimenting. The info in this forum has helped me cut many corners in researching the audio gear needed. I thank you but my wife does not appear to like you guys too much! ;-)

At least until she hears what happens when the needle hits the groove. :-)

dave