So if I have a summing amplifier circuit like the one below:
I know the Vin1, Vin2, and Vout value and the circuit is designed such that Vout = -(Vin1+2Vin2) but how do I calculate the gain? I know on a normal op-amp circuit with one input source the gain is just Vout/Vin. But if I have two input sources then will my gain be Vout/(Vin1+Vin2)?
On PSPICE I set the DC and ACMAG values for the input voltages to 2V, and Vout is -6. So it works out right, but still what is the gain?