dual volume controls?

Needing a balance control does not always mean there is something wrong with the system. More likely than not it is a room problem that may be too difficult and expensive to cure. Very few audiophiles have the perfect room or even a decent room as is evident in system photos on this forum. In most cases the presence of a balance control is much less harmful than the room itself.

Dual volume controls have nothing to do with a dual mono design.

Agree that it usually (unless the stops are detented, as you cannot "fine tune" nearly as much) offers a better form of balance control.

Seems real inconvenient,why not take it a step further and have two mono block preamps with separate power supplies?