Cartridge-- M/M or M/C


Even though I have been back into vinyl for about 9 or 10 months now, I am still a relative newbie. I used to listen to vinyl in the 70's but not the way I do now.
I have a MMF-7 TT with the stock Eroica cartridge. As you know this is a M/C cartridge with what I assume is high output. 2.5 mv. (is that right?)
I guess because of my stupidity it is time to upgrade.
I don't want, or let me rephrase, I can't spend more than $500. What are the character differences between M/C and M/M?
What should I be looking at in this price range?
Thanks, Scott
scottht
Thanks, Rlxl, maybe you could give some details on the Heirloom, which I have heard referred to often over the years, but which I haven't had the pleasure of seeing or hearing. I believe it is a modified AR, or am I totally off the mark?
Since the conversation had went towards decks,
I'd say my understanding on that issue:

Collector DC motors have the largest chaotic electro-magnetic noise. Under chaotic I assume freequencies of a different spectrum with no exempt to transients. Please note, MC cartridges are less affected by such noise thus perform more quiet and more accurate.

AC motors have significantly smaller noise but fully or mostly depend on power-line freequency stability.

Quartz digital motors have even less noise than AC motors thus the most suitable IMO in analogue turntable applications. Yes, DD tables could sound better depending on its construction since the quartz motor influence factors out compared to DC collector motors.

What about belt-driven tables with quartz-digital motors? Probably VPI does that so-far...?
Belts constantly react to groove modulations, stretching and contracting without end, which is why 'tables which offer both belt- and thread-drive capability universally sound better with the thread (which doesn't contract). Get rid of one problem, introduce another, which is why I keep a stable of players. It's been a while since I did any research into various motors: by Collector DC motors I assume you mean the type commonly found on idler-wheel drives? And are you saying that electro-magnetic noise is a bigger issue than speed stability? I am ready to be educated, you seem to know your motor lore and history (I do remember the issue of e-m noiswe in the development of record-players). I have the feeling this thread is a runaway train...What's Scott up to now?
The brushes of DC motors are the main culprit of EM noise. The motor rotates from the physical contact from the brushes-collectors and due to physically unstable contact the transient EM noise occurs while the motor is working.
To visualize or audiolize that effect larger you can bring a drill(corded or cordless) closer to the cartridge and turn it on. You may even see your speaker drivers moove picking up transient pulses. Certainly such are much smaller from the supplied motor but they're present and definitely affect the performance of the system.
Cartridge pickups, microphones and speakers are working on the same effect of electromagnetics. when the current flows through the conductor it induces a magnetic field and bacwads: the moving magnet inside the electric field creates emf i.e. electro-motive force. One way or the other all magnetic systems are vulnerable to EM interfearance.

In AC motors there are no collector brushes and so is EM noise is minimized. The quartz-digital motors we can consider as a special case of AC motor where the freequency of pulse is dictated by quartz.

I never compared or analyzed issues of stability of EM interfearance, but more often myself had issues especially in cheap analogue systems where the system picked up too much of the motor noise that had been a primary reason of poor cartridge performance.