Boomklever, I'm not familiar with that particular Marantz recorder. This sounds like a classic "mic" versus "line" level situation. If the XLR is set to mic, it is meant to have maximum signal of 50 mV, or 1/20 volt. Line level is 1.0 volt max, or about 20 times stronger. If the input gain is set for microphone sensitivity but you are plugging in a line level (such as the output from a pre-amp) it will overload and distort grossly. If the input expects a line level signal, but your are sending a mic level output, you get almost no volume. This is all electrical, and independent of how you mechanically connect them - 1/4", XLR, RCA, using adapters, etc. Hope this helps.....