Bestow upon me the virtues of MM vs. MC

[eeka chu]

MM or MC, which is better for what and why?

Also, how much thought goes into the magnet type, rather than ultimate field strength, in the Hi-Fi world?

Alnico, Ceramic, Neodymium...

For guitarists, the magnet type is something even beginners modding their guitar think about. Just wondering how much this crosses over in the Hi-Fi tonearm world. Makes a BIG difference to the sound of a guitar.

Neodymium - High output, brittle sounding (Thrash)
Ceramic - Lower output, less brittle, has presence (Rock)
Alnico - Usually the lowest output and warmest sounding (Vintage rock, like Van Halen & Hendrix)

I spent a lot of time messing around rewinding pickups, playing with the designs and magnetics. Makes me wonder how hard it'd be to try a DIY cartridge.

[SY]

MM or MC, which is better for what and why?

Both and neither. The best magnetic cartridges I've ever used were about equal numbers of each. But all were very second rate compared to non-magnetic transduction- strain gauges and FM have quaities I've never heard in MMs or MCs. If I were going to diy, I'd look into those non-conventional technologies.

[eeka chu]

Originally posted by SY


Both and neither. The best magnetic cartridges I've ever used were about equal numbers of each. But all were very second rate compared to non-magnetic transduction- strain gauges and FM have quaities I've never heard in MMs or MCs. If I were going to diy, I'd look into those non-conventional technologies.

That's an interesting idea, kind of in tune with the original phonographs.

Peizo technology is still going through it's revolution phase so there's still a lot of improving being done.

I'll check it out!

[nuvistor]

Micro Acoustics used piezo transducers around 1980, MA2002e is probably the most common example. I have one, the sound is not highly refined but seems to work well with '70s rock records. I'd like to hear one of their models with microline stylus.

[Curmudgeon]

I had forgotten completely about the strain gauge cartridges. The Weathers FM was amazing in its time. It foundered on the inability to prevent inter-channel crosstalk when stereo came along, but perhaps modern materials would make it feasible.

And I think there is no single answer to MM vs MC vs Moving Iron. Cost, taste, associated equipment, designers' skills, individuals' budgets all make "best" too slippery to hold.

[ThorstenL]

Konnichiwa,

Originally posted by eeka chu
MM or MC, which is better for what and why?

This is a complex question.

First, any MM Cartridge (excepting the MI types often mis-labelled as MM) will have so much inductance that high frequencies are rolled off. The solution usually employed is to load the cartridge with a significant capacitance to create a resonance circuit to boost the treble up at resonance to partially compenaste for that. All in all suitable only for lo-fi.

An MC cartridge is considerably more linear, frequency response wise and otherwise, tends to have less moving mass.

Next is good to take the different types of styly into account. As long as the tonearm is of the traditional pivoted type, gentle elliptical and/or preferabbly spherical types are needed, extreme stylus shapes are not suited to pivoted tonearms and require linear tracking types to work correctly, preferably with remote controlled or at least easily adjusted VTA/SRA.

Sayonara

[SY]

Curmudgeon (hey, you must be a neighbor!), the Weathers was easily the finest cartridge I've ever heard. There's no reason why it couldn't be done for stereo if someone had a mind to do so.

All in all suitable only for lo-fi.

I've got a Technics EPC100C mk4 that says you're wrong about that.

[Steve Eddy]

Originally posted by SY
I've got a Technics EPC100C mk4 that says you're wrong about that.

Naah. You've just got lo-fi ears.

se

[Curmudgeon]

Paul Weathers broke his pick trying to "stereo-ize" the FM cartridge. He used a carrier frequency of about 100 MHz (???) and the (very small) capacitance between channels caused unacceptable crosstalk. He never did solve the problem. I'm not sure what modden technology could do. Lower frequency, and less modulation needed with current recovery schemes? I think at that time, the Foster-Seeley discriminator was the only demodulator available.

Moving magnets are not inherently inferior. For a long time, MC's had the higher moving mass, and all suffered from a peak at the high end, which in those days I could usually hear. That aside, MC's usually sounded cleaner; but I preferred the original Grado Signature (Moving Iron) to any MC; it was cleaner, and smoother yet. (Joseph Grado thought the MC inferior, despite his having invented and patented it. He received royalties on every MC sold in this country for some years. ) The MM ADC's were very good. You no longer see as a spec, moving mass referred to the stylus, as one could once. In those days, MCs either had substantially greater moving mass, or very low output. That was also the reason why MM's/MI's had better tracking at lower forces. And because the coil could be larger, the MM output was substantially higher, all things being equal. (This could be, and sometimes was traded off against inductance. ) And, as MC's have benefitted from magnet technology improvements, so have MM's.

Nowadays, the point is moot, as there are no high quality MM's being made that I'm aware of. The last entry, the Shure V15, is now out of production. I've had all three over the years, MC currently. (Piezo too in the very early days. Good ol' Sonotone, the student's friend. )

[SY]

It might be interesting to try FM from the other direction- modulating the L. There's a moving-mass penalty, of course, but it might be manageable. It's also tempting to consider a design in a sum and difference mode rather than 45 degrees. Two different carrier frequencies with PLL demodulation? That would have been tough in '58, even for a genius like Paul Weathers.

The wooden arm was wonderful. Silicone damped, deader than dead.