MM and MC cartridge pre amp

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You need on average 20dB more gain for mc as average output is 500uV as opposed to 5mV for mm .

The RIAA curve is the same as this relates to how the music is put onto the disc in the first place .

An additional very low noise , low input impedance amp is usually put in front of a mm amp for mc .
 
same or different?

nigelwright7557: as stated by epicyclic, the curve portion is the same. See the "basic RIAA amplifier " attachment to this post. MC requires a gain stage prior to the RIAA circuit. Both signals require a gain stage(s) as the final output to the pre-amplifier /amplifier playback system.
 

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  • basic RIAA phono stage.png
    basic RIAA phono stage.png
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The recommended impedance varies with cartridge manufacturer ,but a rough guide appears to be from 100 ohms to 500 ohms with some cartridges above and below these figures ........ref SMALL SIGNAL Audio Design ...chapter 8 Moving coil Head Amplifiers....by Douglas Self.
 
BTW: which is the recommended input impedance for a MC preamp?

An MC phono stage (or the head amp which the cart plugs into, which sits before an MM phono stage) needs to be flexible, as regards cart loading. This is most easily done by fixing a 100K resistor on the PCB inside (or across the input terminals) and using load plugs to adjust this down. "Smart" phono stage/head amp designers provide a parallel pair of input sockets ... otherwise, you have to use a 'Y' adaper (if you're using RCAs).

I would widen the range epicyclic suggested ("a rough guide appears to be from 100 ohms to 500 ohms with some cartridges above and below these figures") - I run my Benz LP with 1K5 load and Benz themselves recommend 47K.

Regards,

Andy
 
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