The loading will only be critical if your phono section is sensitive to Radio Frequency Interference (RFI)!
IOW, loading values that small don't affect the cartridge at audio frequencies. You hear a difference because the phono section gets upset if RFI is present.
The inductance of the cartridge and the capacitance of the interconnect cable form a tuned RF circuit that becomes excited (resonates) when energy is supplied by the cartridge tracking in the groove. The resistor detunes the circuit if the value is correct, eliminating the excitation voltage (which is often quite high- in the MHz range).
So- if your preamp is unaffected by RFI you will hear little or no change with the loading.
IOW, loading values that small don't affect the cartridge at audio frequencies. You hear a difference because the phono section gets upset if RFI is present.
The inductance of the cartridge and the capacitance of the interconnect cable form a tuned RF circuit that becomes excited (resonates) when energy is supplied by the cartridge tracking in the groove. The resistor detunes the circuit if the value is correct, eliminating the excitation voltage (which is often quite high- in the MHz range).
So- if your preamp is unaffected by RFI you will hear little or no change with the loading.