Does current flow through the feedback resistor without going through the op-amp at all? After all, the op-amp is supposed to have very high input impedance right, so if the current just flows through the feedback resistor, wouldn't there be nothing going through the op-amp? Also, how does the negative feedback increase the effective bandwidth? I get that the gain is smaller, so the signal won't be saturated and thus effective bandwidth is increased. But why bother with the op-amp at all then? Can't we just use the raw voltage is the gain is low anyway? Is it physically impossible to produce an op-amp with a more reasonable open-loop gain, making feedbacks necessary? Op-amps confuse me P.S this is my first time encountering op-amps so I think they are pretty much introductory questions??