Marantz amps tend to be pretty stout on the PM models, so I'd be inclined to think it will be OK. Based on the rated output for the 5004 though, and these speakers are also listed as 6 Ohms, I'd say you might be pushing it if you expect higher listening levels. For average levels, I think it will be be sufficient. 85dB sensitivity is somewhat low, but not so low that I'd worry about them much with most amps. I like EPOS, but have you heard these speakers yet?