Cartridge Impedance


I just bought a phono pre-amp that allows me to adjust the impedance of a MC cartridge. I was using 100ohms. Now I want to experiment.
Could someone tell me the effect the trebles will have if I lower or raise the suggested impedance. For example, If I raise the impedance will the highs be more prominent or less prominent? 
Thank you.
jmh128

Showing 1 response by mijostyn

Lewm is entirely correct. For LOMC cartridges the input impedance should be set at 10 times the internal impedance of the cartridge or a little above anywhere between 50 and 100 ohms covers most modern cartridges. It is not one of those areas where tweaking makes much difference. Play with different cartridges, move your speakers around, play with different room EQs if you can but messing around here is not productive use of your time. In this regard I always follow the manufacturers recommendation especially if you are dealing with companies like Ortofon and Clear Audio. They know a lot more than I do. 
Input capacitance does make a difference with MM cartridges because it changes frequency response in the audio part of the spectrum. Again the manufacturer will tell you what gives you the flattest response.