Moving Magnet vs. Moving Iron

tg wrote: You know we love your work G - but the question I read was .....but nobody seems to talk about the differences between Moving Magnet and Moving Iron cartridges. So between those two, which is better? And in what ways do they differ in terms of sound?

Must be my age...

I'll let Gary D. Markowitz explain (whomever he is) "it [the Moving Iron] has two small pieces of iron attached to the cantilever perpendicular to the record grooves. They are situated between the magnet and the coil, and the motion of the iron in the magnet's field induces AC current in the coil. One of the advantages of this design is that the moving iron can be lighter than the magnet on a moving magnet design, allowing more powerful magnets and larger coils to be used than a standard moving coil cartridge"

Simple?

So you can have more windings than a low output MC but less than a MM so you don't end up with such a high inductance limiting the frequency response top end.

Great idea!

But what you can get is a difficult to control oscillation due to the inductance: the phono stage designer may have accounted for every possible permutation of MC and MM cartridge, but then the MI is thrown at him...

Which shows phono stages and headphone amps are very similar?

One has to deal with a range of transducers all having their own little foibles and demanding their own matching characteristics at the input - the other at the output.

And then folk ask when will I do a pre and power amp?

As soon as I can escape having to cover for all these transducers...

EDIT: forgot the smiley marks (age again???) arrange as you feel fit


Edited by Graham Slee - 15 Mar 2009 at 1:23pm