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

Showing 6 responses by mofimadness

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.
I've never heard of this kind of change ever harming a preamp or head amp.  All you are doing is changing the value of the resistor.  All associated electronic parts in this chain should have more than enough capacity.
Outside of doing harm to the components, would there be any detrimental effect on the sound if I were to go outside of the manufacturers recommended specs?
No.  Just as analogluvr stated above, sometimes you just need to try it and listen.

Also, the load difference between 100 and 400 ohms is pretty small and you might not even hear a difference.  Depends on the cart and all the associated gear.

I always try to get close to the recommended load, but you never know.

I have owned the same exact unit you have and many, many more that you can replace the resistors in.  You can drive yourself crazy, if you get to concerned about it.
Negligable or... important?
No.  I'd leave it as is and see how it sounds.  Absolutely will not hurt anything.
Generally, if you're loading at X ohms and its sounds a bit dull/lifeless/bass heavy that way, try higher loading to get it to even out a bit. Alternatively, if you're loading at Y ohms and its sounds a bit too sparkly/tinny/HF heavy, then try lower loading. to get it to even out a bit.

That's correct.  Most cartridge loading pertaining to sonics will be very subtle.  The more resolving the system, the more you will hear it, but it will not change the overall sound aspect of the cartridge.

There are some that prefer loading a MC cart at 47K ohms, just like a MM cart.  I have owned a few MC carts that do indeed sound better up that high.

The end game is:  do whatever sounds the best to you.  Again, you can NOT hurt anything doing this.
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...
lew...Ralph states above:

If however, the preamp is properly designed and is stable with RFI, then the loading resistor will be found to have no effect.
and

Our preamps are stable so no loading is needed.
but you are saying it does have an effect?  So what's going on?