Rega Fono MkIII (2017) Moving Magnet Phono Stage Ex Demonstration
For 2017 the new Fono MM is now housed in a brand new redesigned case to match the new Fono MC and Rega's latest range of electronic components offering a modern and sleek look guranteed to integrate in to any hi-fi system.
The RIAA equalization has been split into two stages to minimise interaction. Polyester capacitors have been used in the signal path and polypropylene capacitors are used in the RIAA equalization circuits.
The aesthetic design of the Fono MM was as important as the quality of its electrical capabilities, so it benefits from the same aluminium case as the Rega TTPSU and Fono MC amplifier, giving it a design which offers a familiar feel and moreover brings it in line with its illustrious bigger brothers.
Why do I Need A Separate Phono stage / Pre Amplifier with my Turntable?
RIAA equalisation is a form of pre-emphasis on recording and de-emphasis on playback. A recording is made with the low frequencies reduced and the high frequencies boosted, and on playback the opposite occurs. The net result is a flat frequency response, but with attenuation of high frequency noise such as hiss and clicks that arise from the recording medium. Reducing the low frequencies also limits the excursions the cutter needs to make when cutting a groove. Groove width is thus reduced, allowing more grooves to fit into a given surface area, permitting longer recording times. This also reduces physical stresses on the stylus which might otherwise cause distortion or groove damage during playback.
A potential drawback of the system is that rumble from the playback turntable's drive mechanism is amplified by the low frequency boost that occurs on playback. Players must therefore be designed to limit rumble, more so than if RIAA equalization did not occur.
RIAA equalization is not a simple low-pass filter. It defines transition points in three places: 75 µs, 318 µs and 3180 µs, which correspond to 2122 Hz, 500 Hz and 50 Hz (rounded values). Implementing this characteristic is not especially difficult, but is more involved than a simple amplifier. In the past, almost all hi-fi preamplifiers, integrated amplifiers, and receivers had a built-in phono preamplifier with the RIAA characteristic, but it is often omitted in modern designs, due to the gradual obsolescence of vinyl records. Add-on phono preamplifiers with the RIAA equalization curve are available; these adapt a magnetic phono cartridge to an unbalanced −10 dB consumer line-level RCA input. Some modern turntables feature built-in preamplification to the RIAA standard. Special preamplifiers are also available for the various equalisation curves used on pre-1954 records.