Phono preamp

Short for phonograph preamplifier, a special type of preamplifier designed to handle the output of phonograph cartridges, which are transducers designed to turn the grooves in a phonograph record into electrical energy that can be amplified for a playback system. The phono preamp is a circuit that boosts the very weak signal coming out of the aforementioned cartridges up to more of a line level so it can be properly handled by the other components in a hi-fi system. Additionally the preamp’s job is to apply equalization to the signal to restore it to its original form. In order to make it easier to manufacturer phonograph records, and to make them more universally playable, it was determined years ago that special equalization would be applied during mastering. The RIAA came up with an equalization curve – now known as RIAA Equalization – that, among other things, lowered the level of low frequency information relative to other frequencies (See WFTD RIAA Equalization for more background). In order for records to play back properly the opposite EQ has to be employed in the phono preamp. Not all phonograph cartridges require the same amount of and type of equalization though. High end or audiophile preamps allow the user to set certain parameters to better tailor the response of the preamp to the cartridge being used.