I thought this would be a simple request, but the cabling company I've ordered from have got it wrong twice now: I want to connect two mono outputs from my Fireface to an Art Headamp (1/4" stereo jack input). Is this possible, or a bad idea, to effectively use a "splitter" cable in reverse? The cable I've been sent has no signal going to the Right channel of the headphones (both outputs from FF are being sent to left channel). I'm no wiring expert, obviously. Thanks in advance.