I'm looking for a foot switchable 3-in, 1out that has knobs for levels of each in, to facilitate switching between 3 instruments into a single signal chain and amp. I know of the Morley ABC box, but that doesn't have the ability to adjust levels from what I can see. Radial Tonebone Bassbone is only 2 inputs, and is somewhat overkill in other features for my application. Anyone know of something that might work but not break the bank? Not looking to engage custom work.