Arfa Daily wrote:


Actually, a thought now occurs to me. I wonder if the level control is
actually nothing of the (conventional) sort, but rather a variable feedback
resistor for the opamp, as they sometimes are in some amps.

** The volume pot is connected in the usual way between the output of the input balancing stage ( U2A ) and the input of U2B.

FYI:

The QSC model that is near identical to your Alto is the RMX1450.

You will find a much more readable schem in the RMX850,1450&2450 manual from Elektrotanya and without the little errors I see in the Alto one.

http://elektrotanya.com/qsc_rmx_850_.../download.html



..... Phil