The DI on the Spider IV is really a STEREO headphone out.. We were running it direct into the mixer for gigs (1/4") and it sounded pretty good but something just wasn't right.... Unless your taking the signal out of the DI with a TRS "Y" splitter and running 2 separate signals to either 2 separate channels (or a stereo input) on the mixer, you're only getting half of the sound (it is stereo)...
It's VERY, VERY BAD to combine a stereo signal into 1 with a "Y" cable http://www.rane.com/note109.html (good read) so we tried one of these:
Into one of these:
and out to the mixer/snake via XLR.... WHAM!!! The sound was there,, all of it... Full, big and cutting.
Try it,,, You'll like it!!!
PS... I sprung for one of these to add versatility (can run IPod to PA and have a COMBINED mono signal..