I am looking for a battery-operated preamp that will take a mic-level signal from a Shure SM58 and output a true (+4) line-level signal for our 6-way mic splitter. My exhaustive (and exhausting) Google searches led me to the Eventide MixingLink. Reading the specs though, I can’t tell if the MixingLink will work or not. I can find plenty of line-to-mic attenuators, and plenty of preamps that use regular power or phantom power, but nothing battery-powered. I’m starting to suspect such a device does not exist.