2. analog
  3. 132371-104901

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
mofimadness's avatar
mofimadness
4,152 posts
 
If however, the preamp is properly designed and is stable with RFI, then the loading resistor will be found to have no effect.
Ralph...thank you!  I have always considered myself pretty much an expert on vinyl disk systems, but I never knew that.

Always appreciate continued education...
oharchie's avatar
oharchie OP
29 posts
 
@atmasphere 

Yes, thank you. That sums it up very nicely.


bdp24's avatar
bdp24
4,908 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
7,068 posts
 
^^ Yes- loading of higher output cartridges is a different matter!
analogluvr
800 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. 
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