what do you mean by 'load' them? The link you gave me is way beyond what I can comprehend.@terrible "loading" of a cartridge is where a resistance is placed in parallel with the output of the cartridge; IOW from the signal to ground. Many phono preamps have provisions for this. Any high output cartridge will have a peak in its output at a particular frequency which will be at the upper end of the audio band or well past it. The link I provided has the technical explanations of why. Even if the peak is at 40KHz, there is a phenomena called 'phase shift' which can introduce brightness artifacts in the audio band.
The resistor is inexpensive. The value is probably around 10K Ohms. This is assuming that your tonearm cable is actually meant for phonograph use (such cables are low capacitance to keep the peak as high as possible). If you are using a regular audio cable, you might consider finding one that is low capacitance instead (which is not expensive).