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input impedance load on a cartridge.

I am interested in purchasing an MC cartridge that prefers a 400ohm "load"from the pre amp. My head amp for MC cartridges provides 110ohms which is the highest recommendation for the unit (according to the manual). In theory I should be able to change the resistors to alter the load but I am worried that going beyond the recommended value would harm the pre amp/head amp.

Can I alter the resistors to accommodate the cartridge or should I be looking for a different cartridge (or a different head amp)?

I am particularly interested in the possibility of changing the load. The alternative cart/pre option is of secondary interest.


128x128oharchie
bdp24's avatar
bdp24
9,411 posts
 
Keith Herron is a proponent of "infinite" loading of mc cartridges. Gauging by atmasphere’s excellent post above, one can conclude Herron pre’s are also stable designs. Loading of mm and mi cartridges is a different matter.
atmasphere's avatar
atmasphere
11,574 posts
 
^^ Yes- loading of higher output cartridges is a different matter!
analogluvr
859 posts
 
That explains why I almost always like 47K since I have a herron. If I had a chance to try an mp1 I wouldn't turn it down. 
nandric's avatar
nandric
4,086 posts
 

There are the so called ''10x and 20x'' cart impedance rules.

In the user manual of my Klyne 7PX 3.5 there are recomended

loads for 26 '''well known'' carts ; the most 47 K the rest 1 K (9x).


lewm
12,451 posts
 
I have found that 47K is optimal with LOMCs, using my Atma-sphere MP1, of course. The sound seems a bit more open and extended, compared to using loads of 1000 ohms or 100 ohms.  (I have set my MP1 up so I can quickly switch among 47K, 1K, and 100R load resistances, which makes it easy to compare.)  However, even 100R does sound fine, just a bit more closed in.  LOMC cartridges I've tried:  Ortofon MC7500, Ortofon MC2000, Koetsu Urushi, ZYX UNIverse.

The 47K load is kind of an antithesis of "current-drive", for LOMCs.
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