Looking for a stereo 3-4 channel compact mixer

Hi,

I'm looking for a stereo mixer which supports at least 3-4 channels, it must also be very compact as it will be used on a desk top. I've seen a few which have almost done the job, but they've all had at least one problem preventing me from purchasing it (usually it's mono only and my setup requires a stereo setup).

I'm going to be using a DAC plugged in to my desktop PC which will be input 1 on the mixer, input 2 will be my MacBook Pro and input 3 will be from my Android TV.

It would be preferable if the mixer was Active, however a passive mixer with an additional amplifier could work.

As for size, something this sorta size would be the best as it will be sitting on the top of a desk (this mixer would be perfect only it only does mono audio, not stereo):