In case there is anyone on this thread who does not already know this, the convention is to load the cartridge with a resistance that is at least 10 times that of the internal resistance of the cartridge itself. Therefore, a typical low output moving coil cartridge that will have an internal resistance of about 10 ohms can be loaded with 100 ohms, but it can also be loaded with any resistance higher than 100 ohms. Of course, you also have the option to go below 100 ohms with that cartridge. But as the ratio approaches one (internal resistance = phono load resistance), more and more of the signal voltage will be lost to ground. In addition high frequencies will gradually be rolled off. Some people like it that way, and there is nothing wrong with that. This constitutes one of the factors used in thinking about how to load the cartridge. The other factor relates to how the phono stage is designed and constructed. As you increase the load resistance toward 47K ohms, which is usually taken as wide open, the phono stage might in some cases become less stable and develop high frequency resonances. I am referring here to electronic resonance not mechanical. One result can be exaggerated ticks and pops..
