Фонокорректоры — SOtM sPQ-100PS

The sPQ-100PS is a phono stage from the Korean company SOtM that accepts MM and MC cartridges. It is the sPQ-100 equaliser paired with its own purpose-built power supply box, the two boxes being joined by specific connectors that cannot easily be swapped for others. Each of the two cases measures 106 x 48 x 245 mm, and the pair weighs 3 kg in total.

Key specs that matter

Cartridge signal arrives at one stereo RCA input fitted with a ground post. The MM input handles 3 to 10 mV at 1 kHz and can be set to 47 kohm with 100, 150, 220 or 330 pF. For MC the accepted level is 0.1 to 1 mV, with loading of 15, 20, 100 or 500 ohms and 10 pF. Total gain is switchable in four steps of 40, 50, 60 and 70 dB at 1 kHz. The stereo RCA output delivers up to 9.5 V from a typical output impedance of 20 ohms, frequency response spans 20 Hz to 20 kHz, and SNR is 100 dB typical at 1 kHz at maximum output, measured on MC with the RIAA curve at 50 dB gain. SOtM gives a tolerance of 10 percent for signal levels, gain and frequency.

Engineering and use context

SOtM designed the sPQ-100PS to handle the many equalisation curves record labels used before RIAA became universal, so its switches on the top panel shape the curve rather than offering RIAA alone. Bass boost can be set to 14.5, 16 or 20 dB at 20 Hz, or to 33 dB at 7 Hz with no bass shelf. Bass turnover is selectable at 250, 354, 500 or 800 Hz, and high frequency roll off at 1592, 2122, 2500 or 3183 Hz. Together these switches allow matching of older mono and stereo pressings from different labels. The maker states that the circuit uses its own noise reduction technology. The power supply unit accepts 100 to 240 V at 50 or 60 Hz with a current rating of 2.5 A, which SOtM lists as a wide input voltage range, has an AC switch on the rear panel, and both cases carry an operating LED. Storage conditions allow 10 to 90 percent humidity. Both operating and storage temperature are specified from 0 to 40 degrees Celsius.

Pairing

With the highest gain step and MC loading down to 15 ohms, the sPQ-100PS suits low output MC designs, and the 47 kohm setting and adjustable capacitance serve moving magnet types. Any preamplifier or integrated amplifier with a spare line level RCA socket can take its output. Collectors of pre-RIAA records get the most from the curve switches.

Alternatives

SOtM currently offers no other phono stage, as the sPQ-100 is its only phono equaliser.