Inverting input impedance question.

[Chugs]

Browsing schematics recently I have seen a couple of pedals that have a volume control on the inverting inout of an opamp as depicted in the schematic attached. Usually the resistor in series with the inverting input sets the impedance of the opamp but what about in this configuration? (VB is 4.5V bias)

Is the impedance the combination of the resistor and the pot value? So 100K plus 100K = 200K

Or does the impedance vary with different settings of the pot?

Or is the impedance still the value of the resistor in series with inverting input? 100K

[anotherjim]

Pin 6 is virtual ground and Vb, assuming it is properly AC bypassed, is also ground. So you have the input resistor + the 2 halves of the pot track in parallel. With the pot centred, it's 100k + 50k||50k = 125k. Pot at min or max, it's 100k.

[Chugs]

Thanks, that makes sense.