In the hey day of vinyl records and hifi it was expected to find an input marked ‘Phono’ on the back of a hifi or music centre. This would usually be flanked by such inputs as Aux, Tape, Tuner and later on CD. If you had a record player then it could only be connected to the phono input whilst all other things could pretty much be connected to any other input. The reason for this is that behind the phono input lay a special bit of electronics that was needed to play back the vinyl recording properly. Latter day hifi tends not to have this bit of electronics inside and this ‘phono stage’ bit of electronics tends to be available as a separate box of kit.
In the days when vinyl recording was developed, in the early part of the twentieth century, the limitations of the technology to hand meant that clever techniques had to be employed to get the best out of the medium. The principle was to boost the high frequencies (treble) and attenuate the lower frequencies (bass) at the manufacturing stage and then reverse the process using the ‘phono stage’ equalised pre-amplification to play back the recording in its original form. The technique was standardised in the mid 1950s to the version most widely available today, the RIAA (Recording Industry Association of America) equalisation curve and the more recent evolution of the original, the IEC (International Electrotechnical Commission) equalisation curve. Both versions of which are used on the Sonneteer Sedley phono stage.
The advent of the phono stage as an entity may have been borne of the demise of the vinyl record in the mainstream, but the event has brought with it many positives from the old technology. By taking the electronics out of the cramped environment of the integrated hifi system and into its own box, more advanced techniques could be employed to produce higher quality circuits and hence far better sounding systems. As the recording medium has become more niche, the better and more available the equipment to play them on. It is therefore arguable that there has never been a better time to play your 33s and 45s than now.
Sonneteer, as mentioned, have a standalone phono stage in their line up and as a bow to the aforementioned heyday the Sonneteer Campion integrated amplifier also employs one internally.