What cartridge, what output?

Your answer to (c) means that, as Raul correctly stated, your phono stage was designed for MM or high output MC cartridges. They are designed to work into a 47Kom load.

Mid- and low-output MC's are designed to work into loads ranging from 5Kohms all the way down to 50 ohms or below.

If you plugged a mid- or (especially) low-output MC into a 47k phono input, the result would typically be a rising top end, resulting in a peaky or shrill tonal balance. MC cartridges must see the impedance they were designed for to provide flat frequency response, and your phono stage is not designed to do that except, as I mentioned, for high-output MC's, say 2.5mv or above, many of which are designed for a 47k load.

The problem with HOMC's is that, to achieve that high output (and use a 47k load), more coils must be wound on the armatures. This additional moving mass attached to the cantilever defeats the very purpose of the MC design, which was and is to remove moving mass from the cantilever. This is what gives low-output MC's their superior speed through transients compared to MM's. High-output MC's give away most if not all of that advantage, so what's the point, other than spending more money?

Mid-output MC's retain some of the MC advantage (somewhat fewer coils, so lower moving mass), but your phono stage won't provide the impedance they require (typically around 500-5k ohms). You could place resistors across your phono inputs to achieve a suitable impedance for a mid-output MC, but this would reduce cartridge output, so you couldn't go quite as low as 0.5mv and be sure of adequate gain. Still, this is a possible solution if you insist on trying an MC. The precise resistor value would depend on the cartridge, every MC is different in this respect.

You could also use a stepup transformer or head amp. This would provide more gain and adjust impedance, allowing you to go all the way to low-output MC's and reap the benefits. This, however, would greatly exceed your budget.

Given the parameters of your existing equipment and your stated budget, I agree with Raul. As to which MM's to try, his experience far exceeds mine (or nearly anyone's), but many of them can be found on ebay or the like at silly low prices, allowing you the luxury, fun and learning that comes from trying several.

Good luck in your search. As my preamp/amp designer says, tolerate equipment, enjoy music!
Doug

Dear friend: As I told you the MM alternative is the way to go and in those cartridge different lines ( Clearaudio, Ortofon and Nagaoka. ) you can achieve what you are looking with out any risk passing the a,b,c points that Doug posted.

You say you have a MM cartridge, could you share which one?

There are almost " hundreds " of MM cartridges that are different of what you have and your phono stage seems to me was designed more thinking in MM cartridges than i MC ones due to its 47K input fixed impedance.
You can run too a HOMC but IMHO the MM alternative is the best for you and your budget.

Now ( in your price range and according your phono stage. ), I can't see a MC cartridge that can perform better than a MM cartridge at the same price.

Regards and enjoy the music.
Raul.

Doug - Thank you very much. I appreciate the information and what you say about preferences.

My BAT preamp manual says the default cartridge loading resistance value for the phono module is fixed at 47k.

I listen to most kinds of music, with some emphasis on classical, but also jazz (especially New Orleans and ragtime and vocal), some country, some pop, some rock (although my rock library does not go beyond the early 70's). I like delicious mid-range, not too bright a sound, deep solid bass. Detail is good, so long as it does not make fun of the rest of my system. My records are mostly in very good condition and I am in the process of buying a VPI cleaner. I have a fairly extensive library of music on my iMac, played through this system and through another one with similar components, but I do like records and I want to find a cartridge that will make the most of the difference between analog and digital.

Doug's response to the original post is about the clearest, most well-reasoned response that I have read on this subject. Even better, with some modification to component category, it can be applied to other "what do you recommend" type posts. Very well done and excellent advice.

Technically, you must choose a cartridge that will:
a) not be obviously incompatible with your tonearm, and
b) not be obviously incompatible with your phono stage gain, and
c) not be obviously incompatible with your phono stage input impedance.

Regarding (a)
According to the information posted at http://www.cartridgedb.com/ your Sumiko Premier FT-3 has an effective mass of 14gm. That makes it generally compatible with a wide array of medium compliance cartridges. Anything with a dynamic compliance around 11-15 CU is unlikely to have any obvious problems (which is all those formulae are good for).

Regarding (b)
Your phono stage gain, as the KAB site and Syntax said, should be fine for any cartridge having an output of 0.5mv or above, which means the majority of MC's. Except for the ubiquitous Denon 103 (which might not be a great match for your arm) most really LOMC's cost more than your budget.

Regarding (c)
What input impedance setting(s) is/are available on your phono stage's MC input? This will determine the coil impedance(s) that will provide optimal frequency response in your system.

So, we know you need a medium compliance, mid-output MC with an internal impedance of ____ ohms. There are (probably) hundreds of cartridges meeting these criteria. How to narrow the field to brands and models?

Well, we can't. Without knowing something of your musical and sonic preferences and priorities, recommendations would be meaningless. If you posted this question on some forums you'd receive a slew of answers that all boil down to "I like X, I like Y, I like Z."

Most posters on this forum know better than to offer meaningless answers that can only confuse or mislead. Should I tell you which medium compliance, mid-output MC's I like? Should Syntax? Should Raul or Elinor? None of that would mean anything, because none of us knows what YOU like.
Help us out a bit. Answer the impedance question and talk about who you are, musically and sonically.

the area ~ 0.5mV will be fine, there are some out there, Benz, Lyra, Zyx

Thank you for the suggestion. I have a MM cartridge, would like to try a MC, am looking for advice on output and on specific MC cartridges.

Ditto regarding my good friend Raul's answer. I know someone with one of the new Clearaudio MM catridges and it works superbly. I believe he has a Maestro. Excellent and a good match for the gain in your phono preamp.

Dear Twilightround: A very good alternative is through MM cartridges like the ones from Clearudio and Nagaoka or Ortofon.

Here you not only will have a high quality performance but you don't have to worry about gain.

Regards and enjoy the music.
Raul.