Pro-Ject Phono Box MM/MC
Today, many amplifiers do not have a specific phono cartridge inputs. The Pro-Ject Phono Box is an ideal affordable solution for connecting a turntable up to your existing system, and it is also capable of working with both Moving Magnet and Moving Coil cartridges. The output of Phono Box can easily be connected with a line-input on your amplifier.
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 withattenuation 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 equalization curves used on pre-1954 records.
Features
- Metal case shields the electronics from vibrational and electromagnetic interference
- Optimal channel separation through dual-mono circuitry
- Special low-noise ICs used
- Gold plated RCA connection sockets
- Outboard power supply included
- Amplification and RIAA equalisation for MM and MC cartridges
- Phono MM/MC selection switch located at the rear of the unit
- Small size allows installation close to record player
