Фонокорректоры — CH Precision P1

The P1 is a phono preamplifier from CH Precision of Switzerland, placed directly below the P10 in the company's range. Its circuitry is fully discrete and dual-mono, designed in-house, and the chassis is modular, so a single unit can later gain an external supply or be joined by a second P1 for dual-monaural operation. At launch it cost USD 31,500, with the matching X1 supply at USD 17,000.

Key specs that matter

Up to three phono inputs can be fitted, each presented on both XLR and RCA sockets. Two are current-sensing inputs for low-output moving coil cartridges, with an input impedance under 100 milliohm and gain from +44 to +69 dB in 5 dB steps, quoted for a cartridge of 10 ohm internal impedance. The third is a voltage input for moving magnet or moving coil types, loadable from 20 ohm to 100 kohm, with gain from +35 to +70 dB. Balanced output adds 6 dB over the single-ended figures. Equivalent input noise is below -135 dBu on the current inputs and -130 dBu on the voltage input, improving to -138 and -135 dBu with the X1. RIAA accuracy is within 0.1 dB, and THD plus noise stays below 0.01 percent at 1 kHz and 3 V output. Each channel has XLR, RCA and BNC outputs, reaching 8 V RMS balanced or 4 V RMS single-ended. The box measures 440 x 440 x 133 mm, weighs 20 kg and draws 45 W.

Engineering and use context

The current inputs work as a trans-impedance stage - the first stage presents a virtual ground, converting the current generated by the cartridge coils into voltage rather than amplifying a voltage across a load. Since the resulting gain depends on the internal impedance of the cartridge, six gain levels are offered. For the voltage input a Loading Wizard with a built-in spectrum analyser works with a supplied 7 inch test record carrying frequency sweeps to find a suitable load setting. A switchable subsonic filter and the gain controls are reachable from the front, and an 800 x 480 AMOLED screen shows settings. An optional pair of plug-in equalisation modules adds the EMI, Columbia LP, Decca London and DGG Teldec curves for older pressings. The ultimate configuration uses two P1 units and two X1 supplies in four boxes.

Pairing

Two current inputs make it practical to run two low-impedance moving coil cartridges on separate arms, while the voltage input takes a moving magnet cartridge or a higher-impedance coil. The balanced output suits line stages with XLR inputs, such as the CH Precision L10.

Alternatives

The CH Precision P10 is the step-up phono preamplifier above the P1 in the same catalogue.