Loading plugs Perreaux SM3 Preamp

I have some difficulty determining the MC cartridge loading plug values for my cartridges. The manual states that both MM (low gain) and MC (high gain) have an input impedance of 47kOhm. When I measure the resistance at the RCA terminals I get the following values: MM 460kOhm, Load 55kOhm and MC 55kOhm (not sure if this is the proper way to measure it).

When I simply plug 100Ohm in the Load terminals (to match my Denon DL-A100 MC cartridge) the volume is significantly lower than with my Denon AU-S1 SUT connected to MM (the bass is more present with the SUT).

Am I overlooking something? Are the load plugs not simply in series or is the MC impedance not 47kOhm, but 460kOhm?

Thanks for your help.

P.S. I am not very technical, so please be kind 😉
 

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Its unlikey that the combined gain on the mm input and step-up combined will match the gain of the mc stage. So ignore the level discrepancy.

If you want to tilt the response to give the impression of enhanced bass try a lower value loading plug. 80 ohm should be noticeable.