Do you fancy experimenting and moving off the HiFi track? In the professional studio world you are describing a "monitor controller".
Studio kit is mostly balanced because a variety of different things are being plugged and unplugged all the time and minimising earth loops and maximising S/Nr is necessary.
Some kit, like the Crane Song and Coleman are remote-controlled rack mount, so probably not suitable. Something like the SPL Elector / Director or Drawmer MC1.1, 2.1 3.1 etc. might be worth investigating. The latter are cheap enough to consider as experiments.
What you won't get though is any HiFi cachet.
Studio kit is mostly balanced because a variety of different things are being plugged and unplugged all the time and minimising earth loops and maximising S/Nr is necessary.
Some kit, like the Crane Song and Coleman are remote-controlled rack mount, so probably not suitable. Something like the SPL Elector / Director or Drawmer MC1.1, 2.1 3.1 etc. might be worth investigating. The latter are cheap enough to consider as experiments.
What you won't get though is any HiFi cachet.