I want to buy an ART Dual USB Pre to power a second pair of condenser mics for my Tascam DR-60. The ART USB Pre has separate Left and Right 1/4 inch balanced (TRS) outputs. The Tascam DR-60 has a single 3.5mm TRS input for channels 3 and 4. I know that I need a dual 1/4 male to single 3.5mm TRS male adapter. My QUESTION is: Do the dual 1/4 inch plugs need to both be TRS, or can they be TS with only the single 3.5mm being TRS? Thanks