Originally Posted by redroom
I have one of those little art gizmoa they work really well but they shure in hell change the sound thats why Im happy with a Y cable.
Yeah, I imagine they do, particularly on the transformer isolated side. I think anything you do is going to change the sound a bit.
You could try recording something that's reproducible, like playing a recorded sound through a speaker and recording that with the mic. Then try hooking up the y cable to both preamps and see if the sound changes significantly. I'm guessing that it'll be noticeable, but probably not bad enough to make comparisons done that way unusable.
Anytime you change the topology of a circuit, you're going to change how it responds to signal a little bit. I don't think there's any way around that.