[ec]

Hi all

What is the diference between MM and MC phono cartrdige from the preamp pont
of view ?

Thanks
ec

[John]

MM cartridge has a higher inductance than a MC ( appox. 600mH compared to 15mH ).Also
when designing a tube phono preamp the miller capacitance takes a major role in dictating the
high frequency response as the XL changes in the phono cartridge across frequencies.

"ec" wrote:

Hi all

What is the diference between MM and MC phono cartrdige from the preamp pont
of view ?

Thanks
ec

[Peter Wieck]

On Feb 26, 3:46 pm, "ec" wrote:
Hi all

What is the diference between MM and MC phono cartrdige from the preamp pont
of view ?

Thanks
ec

MM = Moving Magnet: Output is in millevolts and it will require a
phono-pre-amp stage ahead of the standard line-level pre-amp. The
stylus is attached to a magnet that vibrates between two (if stereo)
coils causing AC current by induction. Naturally, the magnet is of
(relatively) high mass in order to generate sufficient current.
Relative to what? Read on:

MC = Moving Coil: Output is in microvolts, and requires (misnomered) a
"head amp" (active) or specialized transformer (passive) to match that
Phono pre-amp noted above also ahead of the standard line-level pre-
amp. The coil (2 if stereo) moves within a large(er) magnet causing
induced currents within the coils. Because the coils are so tiny,
current is much less _and_ the coils are also hard-wired. With these
cartridges, stylus replacement cannot be done by the user as the
entirety is a single assembly. And, the coils are of much less mass
than the magnets in the MM cartridge, so greater compliance is
possible... not always achieved.

There are advantages to both, but the typical MC cartridge requires
additional hardware, is not user-friendly (stylus replacement), is
mechanically more sensitive to damage or accident and so forth. As far
as the records are concerned, there is no significant difference, as
tracking forces are, all things being equal, about the same given the
designs. Had I not tripped over a life-time supply of Ortophon MC
cartridges and their various head-amp options years ago, I would not
have considered that option. Opinions differ.

Peter Wieck
Wyncote, PA

[Patrick Turner]

ec wrote:

Hi all

What is the diference between MM and MC phono cartrdige from the preamp pont
of view ?

Thanks
ec

MC has low rated output, usually below 1mV,
MM has high rated output usually above 2mV.

This means that for a typical MC cart with say 0.4mV output
you need more amplifier gain and a much better
signal to noise ratio than for an MM cart.

Patrick Turner.

[Phil Allison]

John

MM cartridge has a higher inductance than a MC ( appox. 600mH compared to
15mH ).


** Wanna try *15 uH * instead??

Equates to about 2 ohms reactance at 20 kHz.





........ Phil

[Trevor Wilson]

"ec" wrote in message
...
Hi all

What is the diference between MM and MC phono cartrdige from the preamp
pont of view ?

**In theory, nothing. In practice, things are USUALLY quite different. The
reason being, of course, is that there have been high output MC carts and
low output MM carts. These not the usual state of things, however. Other
than all that, Peter Wieck has provided a reasonably comprehensive answer.


--
Trevor Wilson
www.rageaudio.com.au





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