Thank you, Everyone, for your input. Before I give up on them, I will get a multimeter. I need one anyway to work on my motorcycles. Once I get that, I will have a look at those measurements, Al. Given that the 12k input impedance may be an issue, and that the ratio of the output impedance of the pre-amp and input impedance of the amp has some importance (from what I've read), maybe the Rotel pre-amp might make a difference? I know I checked the specs on the Rotel pre-amp as compared to the amp, and they didn't seem to be too bad with respect to that ratio. But, I have no idea what the output impedance is from my Marantz right now. The Rotel pre-amp comes tomorrow, and I'll have a listen to it tomorrow night.
I didn't even know they made adaptors for RCA to balanced. I will also check those out. I do like the clarity and separation of the voices, piano notes, etc. But, I was listening to it again tonight, and it seems like the low mid-range is just way accentuated (louder) than the rest of the music. Tones like mid-frequency organ notes tend to overwhelm the rest of the spectrum a bit. Interestingly, Miles Davis sounded amazing on it last night. Just not much else.
I didn't even know they made adaptors for RCA to balanced. I will also check those out. I do like the clarity and separation of the voices, piano notes, etc. But, I was listening to it again tonight, and it seems like the low mid-range is just way accentuated (louder) than the rest of the music. Tones like mid-frequency organ notes tend to overwhelm the rest of the spectrum a bit. Interestingly, Miles Davis sounded amazing on it last night. Just not much else.