in 1931, in motion picture discs. Equalization Since the late 1950s, almost all phono input stages have used the RIAA equalization standard. Before settling on that standard, there were many different equalizations in use, including EMI, HMV, Columbia, Decca FFRR, NAB, Ortho, BBC transcription, etc. Recordings made using these other equalization schemes will typically sound odd if they are played through a RIAA-equalized preamplifier. High-performance (so-called "multicurve disc") preamplifiers, which include multiple, selectable equalizations, are no longer commonly available. However, some vintage preamplifiers, such as the LEAK varislope series, are still obtainable and can be refurbished. Newer preamplifiers like the Esoteric Sound Re-Equalizer or the K-A-B MK2 Vintage Signal Processor are also available. In the 21st century Turntables continued to be manufactured and sold in the 2010s, although in small numbers. While some people still like the sound of vinyl records over that of digital music sources (mainly compact discs), they represent a minority of listeners. As of 2015, the sale of vinyl LPs has increased 49–50% percent from the previous year, although small in comparison to the sale of other formats which although more units were sold (Digital Sales, CDs) the more modern formats experienced a decline in sales. In 2017, vinyl LP sales were slightly decreased, at a rate of 5%, in comparison to previous years' numbers, regardless of the noticeable rise of vinyl records sales worldwide. Although largely replaced since the introduction of the compact disc in 1982, record albums still sell in small numbers and are available through numerous sources. In 2008, LP sales grew by 90% over 2007, with 1.9 million records sold. USB turntables have a built-in audio interface, which transfers the sound directly to the connected computer. Some USB turntables transfer the audio without equalization, but are sold with software that allows the EQ of the transferred audio file to be adjusted. There are also many turntables on the market designed to be plugged into a computer via a USB port for needle dropping purposes. See also Archéophone, used to convert diverse types of cylinder recordings to modern CD media Audio signal processing Compressed air gramophone List of phonograph manufacturers Talking Machine World Vinyl killer Notes References Further reading Bruil, Rudolf A. (January 8, 2004). "Linear Tonearms." Retrieved on July 25, 2011. Gelatt, Roland. The Fabulous Phonograph, 1877–1977. Second rev. ed., [being also the] First Collier Books ed., in series, Sounds of the