I have a Pioneer C-90 that I plug my turntable into. The spec sheet says that input impedance for the MM stage is 50kΩ. It also contains two settings for MC cartridges labelled 40Ω and 3Ω. The literature all says that these are the input impedance. However, I think that may be an error. I suspect they really mean "this setting is for cartridge with 40Ω internal impedance" and "this setting is when you have a 3Ω internal impedance". Both those values seem way too low to be the actual impedance.
I use the 40Ω setting for for my Denon DL-103 (which has an internal impedance of—you guessed it–40Ω). It sounds like it is working correctly. Swordfishtrombones sounds like Swordfishtrombones whether I play it on CD or vinyl.
The service manual is here. I am actually too stupid to make any sense of it (otherwise I would have posted just the relevant sections here). Someone on another forum briefly mentioned that it contains transformers and that calculating the loading is impossible. No idea if that is true.
I use the 40Ω setting for for my Denon DL-103 (which has an internal impedance of—you guessed it–40Ω). It sounds like it is working correctly. Swordfishtrombones sounds like Swordfishtrombones whether I play it on CD or vinyl.
The service manual is here. I am actually too stupid to make any sense of it (otherwise I would have posted just the relevant sections here). Someone on another forum briefly mentioned that it contains transformers and that calculating the loading is impossible. No idea if that is true.