Прочие устройства — Accuphase PS-1250 230V

The PS-1250 is a Clean Power Supply from Accuphase, an AC power regenerator that rebuilds the mains waveform for audio components connected to it. It dates from 2023 and is made in two mains-voltage versions. It belongs to a family of Accuphase power supplies that also includes the smaller PS-550.

Key specs that matter

The rated continuous capacity is 900 VA. Output voltage is 230 V ±3.0 V (±1.5 V on the 120 V version) at a frequency matching the input, 50 or 60 Hz, and output current is 3.9 A (7.5 A on the 120 V model). Distortion of the output waveform is 0.08% or less. The unit accepts 230 V ±10% at the input and draws 55 W with no load, 37 W for the 120 V version. Cooling is by natural convection, and eight AC outlets are provided. The PS-1250 measures 465 x 243 x 499 mm and weighs 41.3 kg, while the 120 V version weighs 42.1 kg.

Engineering and use context

The PS-1250 creates its own reference sine wave. It detects the zero crossings of the incoming mains, forms a square wave, and filters it through a two-stage band-pass filter and a six-stage band-elimination filter to produce a clean sinusoid. The incoming supply is compared with this reference, and a waveform correction amplifier adds what is missing and removes what is in excess. Accuphase states that the third harmonic falls from -40 dB to -80 dB in this process. Noise is removed in three stages, first by a line filter, then by a shielded toroidal transformer that deals with common-mode noise, and finally by the correction amplifier. The shaping works entirely in the AC domain, with no conversion to DC and no oscillator, and the reference signal is transmitted in balanced form. The output stage uses 20 parallel push-pull pairs, and two 48,000 µF 100 V capacitors filter the supply. Protection circuits monitor temperature, DC and AC faults and current. The front panel shows an output meter scaled to 1,200 VA, input and output voltage, input and output distortion up to 6%, and a display of the input and output waveforms, and the display can be switched off. The front is finished in champagne and the side panels in high-gloss aluminium.

Pairing

Accuphase explains that the VA rating of a load is usually 1.2 to 1.8 times its rating in watts. The total load at maximum volume should stay within the rated capacity, and an indicator blinks when it exceeds the top of the meter scale. Source components, preamplifiers and moderate-power amplifiers fit within this capacity.

Alternatives

The Accuphase PS-550 is a smaller Clean Power Supply rated at 510 VA with the same eight outlets.