I am probably wrong, but here is my confusion:
Headphones are stereo with just one 1/4" TRS jack aren't they? My sound card is a MOTU Ultralite, which can take TRS or mono 1/4" plugs. I can use 2 mono inputs per turntable and it works fine. I have a cable which converts 2 RCA plugs to 1 TRS jack. With a plug like this isn't it possible to convert the 2 signals to 1 stereo signal? If it were a mixer with a headphone output it could ouput stereo to one 1/4".
Aside from the cable, i have a Behringer Microphono PP400 Phono Preamp
PP400->
http://www.musiciansfriend.com/product/Behringer-Microphono-PP400-Phono-Preamp?sku=187200&src=3WFRWXX&ZYXSEM=0&CAWELAID=26019422It has 2 RCA input, but has 1 x 1/4" output, which I believe should be stereo? if it were, if it were programmed into Mixvibes wouldnt it be possible to read a stereo signal for each turntable from just 1 x 1/4" TRS input instead of 2 x mono 1/4" signals? My interface only has 8 inputs, after using 2 for each turntable, then 2 more for the mixer signal for scratching, I'm only left with 2 inputs...
Please excuse me if this post seems dumb / redundant.
Thank You!