This is not an adv. I have no relationship with FOSTEX what so ever. It just happens to be the smartest way to add booth volume control to any ITCH controller that has double outputs but no individual volume control (ie DDJ-S1, VCI-300).
www.fostexinternational.com
For me it ticks all the boxes
1) It's passive. No extra AC cables, no compromises in audio quality
2) It's small... or should I say tiny. At 52(W) x 37(H) x 60(D)mm it can fit in any bag and on any booth
3) It's cheap. Most retailers have it at $30
4) All you need is an RCA to 1/4'' cable (not included) and RCA to RCA (included) or RCA to TSR/XLR (not included) cable, depending on your monitor of-course
Hell, I'm ordering one right now!