Hi,
as a current owner of several original helios modules, and a former owner od several other types of Helios modules, both active and passive eq's, I suggest that going in and out un-balanced is a good idea. I have tried several different trannies in and out, and I can honestly say that they sound best un-transform(er)ed. They sound loads better imho going unbalanced Line-in than Mic in padded. Just give it a try if you don't believe me. Strange, since the mic pres are pure sex! I only have modules with the tiny Beyer trannies at the mo, but I have had Lustraphone, and also some big Sowter inputs on my stolen Active 3 band eq's.(If it was you that stole them, I am coming to get you, and it is going to hurt quite a lot when I find you . . . . ) My life is NOT the same without them.
Let me know if I can help!
ANdyP