Прочие устройства — Accuphase PS-1250 120 V

The PS-1250 is the sixth generation of the Accuphase Clean Power Supply line, succeeding the PS-1230. The series began in 1997 with the PS-1200 and moved through the PS-1200V, PS-1210, PS-1220 and PS-1230 before this model. This is the version for 120V mains, with a separate build for other regions. Rather than passively filtering the wall supply, the unit regenerates it, comparing the incoming mains waveform with a clean internal reference and then adding what is missing and removing what is excess.

Key specs that matter

The 120V model delivers 900 VA continuously, while the 230V build is specified at 1,200 VA and 5.2 A with an instantaneous peak current capacity of 80 A. The guaranteed total harmonic distortion of the output waveform is 0.08% or less. Output voltage is held to 120V within 1.5V, or 230V within 3.0V on the other version. No-load consumption is listed at 50 W. The chassis measures 465 mm wide, 243 mm high and 500 mm deep, and the net mass is 41.7 kg. The front panel carries a color liquid crystal display that plots the input and output waveforms, and a switch changes it to show total power drawn, input and output voltage, or input and output distortion ratio.

Engineering and use context

Inside, the layout mirrors an Accuphase stereo power amplifier, with a big, efficient toroidal transformer plus two 48,000 uF filter capacitors at the centre and a power amplifier block on each side. Each block has two output stages of 10 parallel bipolar transistors, driven fully in parallel, which gives high peak current and a low output impedance, and the inputs to both blocks are balanced. In the reference signal generator, a limiter comes first, followed by two band pass stages that bracket three band eliminate stages, so out-of-band noise and harmonics are removed before the reference is used for waveform shaping. All internal wires to the outlets are cut to the same length so every socket behaves identically. High-sensitivity protection circuitry guards the output, and the front panel also carries a meter off switch and LED illumination, with aluminium side panels finishing the case.

Pairing

The continuous rating is suited to a complete source, preamplifier and power amplifier chain, and heavy amplifiers with large current draw benefit most from the high peak current capacity. The tall, heavy cabinet calls for a strong shelf and free air around its heatsinks.

Alternatives

The Accuphase PS-550 is the smaller Clean Power Supply in the same sixth generation, built around a single power amplifier block and a 510 VA rating.