signal-to-noise ratio

Signal-to-noise ratio is the difference between the nominal level and the noise floor, as defined in the Yamaha Sound Reinforcement Handbook¹. Manufacturers often cite it as a quality measure, such as the Empress Superdelay's 105dB ratio² or the Vahlbruch BBQ's studio-quality figure³. Circuit changes can improve it, as when low-noise opamps replace older ones in a delay's preamp and recovery stages⁴, or when a compressor in a record section yields a stronger average signal and a higher ratio⁵.