What is a characteristic of a grounded-grid amplifier?

In a grounded-grid amplifier, the input signal is applied directly to the cathode while the grid is tied to RF ground. Because the input signal must drive the cathode, which handles the full plate current of the tube, the input impedance of this configuration is inherently low, typically between 50 and 100 ohms. While grounded-grid amplifiers offer excellent stability and do not typically require neutralization due to the grid acting as a shield, their low input impedance means they require significantly more drive power compared to a grounded-cathode configuration. Distractors such as high power gain are incorrect; grounded-grid amplifiers actually have lower power gain than grounded-cathode designs, though the drive power does add to the final output.