Bit of a mickey mouse solution but you could just pick up a cheap DJ mixer to do the job if your on a tight budget.

Im without a desk and am using an old ecler DJ mixer to control the line between a Delta 66 and the Alesis active monitors... Has done the job quite nicely for the last few months

Not ideal but has stop me blowing my head off when hitting playback....


Sorry just noticed you said your already doing this....