The receiver gain (RG) characterizes the amplification of the signal coming from the sample; the higher the gain, the greater the amplification. This parameter is usually adjusted automatically; the system varies the gain values until the signal fills the range of the receiver without being cut off, or truncated. An RG that is too low is inefficient, as it does not fully utilize the voltage (y) range of the system's digitizer:

In practice, when the computer is allowed to optimize RG, neither inefficient digitization nor signal clipping will likely be an issue. The problem may be encountered if ¹H spectra of very viscous, concentrated samples are being recorded. The isotopic abundance of ¹H is naturally high, and viscous samples tend to have rapidly decaying FID's in which much of the signal occurs at early times. Both of these factors yield a strong signal, especially at the beginning of the data acquisition, potentially leading to receiver overload.