Hi fuzzyboy,I assume when you are saying transport you mean transformer? I have setup many Genelec DSP sytems and have utilised many if not all of the available options of getting signal into them.I have successfully used a S/PDIF (RCA) output of a CD transport, simply using a RCA-XLR cable, i have used USB soundcards that have AES/EBU outputs. The Genelec input is robust enough to accept the 75 Ohm signal, one note is that i made sure that the RCA-XLR cable was as short as possible, less than 2 Metres. If you need to run a cable longer than that i would recommend sticking to an AES signal.You are correct about the GLM, the 8240's require GLM and not the .SE versionGood luck, once you have the system up and running you will love it.
A while ago, Genelec informed me their monitors would be happy take in both 75 ohm and 110 ohm, SPDIF or AES (the difference between the formats is only a self-identifying bit that Genelec ignores). As 1038 wrote, unbalanced cable should be short, lest interference is picked up. In any other regard, there’s no difference in sound between balanced and single ended cables.
You’ve mentioned Mutec as intermediary. From my experience, you’ll get better sound if you go computer USB to a SPDIF or AES converter. It usually re-clocks the signal and eliminates jitter. I’ve checked a few. The best and most economical is Schiit Eitr @ $179. Beats the Mutec MC 3+ @ $1,100… You can then use a coax RCA -> XLR cable into your Genetec. If you’re stickler like me and want to bump up to 110 ohm, you can get a Nuetirk impedance converter or a Funk cable.