Hi…..This is a good question and to answer it correctly requires an understanding of gain structure, which is a relatively simple thing that nonetheless gets overlooked/badly misunderstood by a lot of people.The amount of signal (headroom) that a device can handle is determined by the voltage rails that power the device. A typical op-amp chip can be powered by between +/- 15 volts, which gives a peak to peak voltage swing of 30 volts*. A device powered by a single 9 V battery has a peak to peak swing of ( volts (in practice slightly less), or the same as running 4.5V rails.
