Terri; assuming that your phono preamp has sufficient gain for a low output moving coil cartridge (0.3mV), I would suggest either an Audio-Technica AT33PTG II from Audio Cubes II or a Dynavector DV-20XL sold by several online retailers. The AT33PTG II is selling for $630 USD and the DV-20XL for $850 USD.
I'm currently using the earlier version of the 33PTG and ran a 20XL for a few years and both cartridges are a very good match with the mmf-7 turntable. I had to purchase a heavier tonearm counterweight to accomodate the added weight of the 33PTG (6.9g) and 20XL (9.1g) vs the Eroica (5.5g) but the Music Hall 120g heavyweight counterweight is available from MusicDirect for $30; product no. AMHHEAVYWEIGHT.
Both the 33PTG and 20XL have a more refined sound than the Eroica, with better articulation of notes and more natural sounding vocals and stringed instruments for example. The Eroica, on the other hand, has a somewhat more robust and lively presentation, especially in the mid-range; great with rock and blues music. But the Eroica doesn't have quite the composure in conveying the shimmer of cymbals or the high sibilance of female vocalists as well as the 33PTG and 20XL. The 33PTG isn't quite as dynamic as the 20XL and is a bit more forward sounding, although the 20XL is probably on the dark side of neutral. Both are very quiet in the groove and great at minimizing surface noise.
The 33PTG is the better tracking cartridge and less sensitive to azimuth and tracking distortions than the 20XL on the Pro-Ject 9 aluminum arm, but once the 20XL is dialed in it does it's job well.
Keep in mind that the differences are more subtle than obvious, especially between the 33PTG and the 20XL. Also consider that the 33PTG and 20XL have recently been revised and may have slightly different characteristics than the (previous) versions I'm describing. But I wouldn't expect that the cartridges were changed significantly since both are highly regarded in their respective price classes and Audio-Technica and Dynavector probably don't want to mess up a good thing.
The Eroica H is a good HOMC cartridge in it's own right so don't expect that you'll hear a dramatic difference by switching to a LOMC cartridge in the same price range. Nonetheless, when I made the switch I did find that I preferred the refinement and articulation that these low output moving coil cartridges provided.
Tom
PS: Even though I recommend the AT33PTG II, keep in mind that it is NOT distributed by Audio-Technica in the USA and so does not come with a USA warranty. If you have problems with the cartridge you're subject to the customer service provided by Audio Cubes II and not Audio-Technica USA. I received a defective 33PTG and had to send it back to Audio Cubes II in Japan for replacement. It took some time and many email correspondences, but the replacement service was provided in the end.
I'm currently using the earlier version of the 33PTG and ran a 20XL for a few years and both cartridges are a very good match with the mmf-7 turntable. I had to purchase a heavier tonearm counterweight to accomodate the added weight of the 33PTG (6.9g) and 20XL (9.1g) vs the Eroica (5.5g) but the Music Hall 120g heavyweight counterweight is available from MusicDirect for $30; product no. AMHHEAVYWEIGHT.
Both the 33PTG and 20XL have a more refined sound than the Eroica, with better articulation of notes and more natural sounding vocals and stringed instruments for example. The Eroica, on the other hand, has a somewhat more robust and lively presentation, especially in the mid-range; great with rock and blues music. But the Eroica doesn't have quite the composure in conveying the shimmer of cymbals or the high sibilance of female vocalists as well as the 33PTG and 20XL. The 33PTG isn't quite as dynamic as the 20XL and is a bit more forward sounding, although the 20XL is probably on the dark side of neutral. Both are very quiet in the groove and great at minimizing surface noise.
The 33PTG is the better tracking cartridge and less sensitive to azimuth and tracking distortions than the 20XL on the Pro-Ject 9 aluminum arm, but once the 20XL is dialed in it does it's job well.
Keep in mind that the differences are more subtle than obvious, especially between the 33PTG and the 20XL. Also consider that the 33PTG and 20XL have recently been revised and may have slightly different characteristics than the (previous) versions I'm describing. But I wouldn't expect that the cartridges were changed significantly since both are highly regarded in their respective price classes and Audio-Technica and Dynavector probably don't want to mess up a good thing.
The Eroica H is a good HOMC cartridge in it's own right so don't expect that you'll hear a dramatic difference by switching to a LOMC cartridge in the same price range. Nonetheless, when I made the switch I did find that I preferred the refinement and articulation that these low output moving coil cartridges provided.
Tom
PS: Even though I recommend the AT33PTG II, keep in mind that it is NOT distributed by Audio-Technica in the USA and so does not come with a USA warranty. If you have problems with the cartridge you're subject to the customer service provided by Audio Cubes II and not Audio-Technica USA. I received a defective 33PTG and had to send it back to Audio Cubes II in Japan for replacement. It took some time and many email correspondences, but the replacement service was provided in the end.