Accuphase PS-1200 (1997)
High-capacity clean AC power supply designed to deliver stable, low-distortion voltage to audio systems.
Overview
The Accuphase PS-1200 Clean Power Supply was released in April 1997 by Accuphase Laboratory, Inc. of Japan as a high-power version of the PS-500. Designed for audiophiles seeking improved power delivery, it uses waveform shaping technology to correct incoming AC power, regenerating a clean 120V or 230V output with a total harmonic distortion of 0.3% or less. It does not regenerate AC from DC but instead continuously monitors the input waveform and adjusts it using an internal sine wave reference, adding or subtracting power as needed. The unit features 7 AC outlets—5 on the back and 2 on the front—and includes a central meter to monitor input/output voltage, distortion, and connected equipment power draw.
Specifications
| Rated output capacity | 1,200 VA (continuous) |
| Rated output voltage | 120V/230V (constant) |
| Instantaneous current supply | 120A/60A (inrush) |
| Output waveform THD | 0.3% or less |
| Input voltage range | 108–132V / 200–253V AC |
| Input frequency | 50Hz/60Hz |
| Input capacity | 1,500 VA (at rated output) |
| Power consumption (no load) | 60W |
| Cooling system | Natural air cooling |
| Dimensions | 475W × 242H × 508D mm |
| Weight | 37.2 kg |
Design
The PS-1200 uses a pure complementary symmetrical circuit with a current feedback amplifier for waveform correction, driven by 20 parallel push-pull output transistors rated for 16 amperes each. A super-ring type toroidal transformer rated at 1,500 VA provides power, with primary and secondary windings fully separated and shielded. The input includes a line filter to suppress high-frequency noise, and an AC feedback system ensures very low output impedance. The front panel features a central meter with a selection knob to display power draw, voltage, or distortion levels, and a heavy-duty power switch that also acts as a circuit protector. Protection circuits guard against input current overload, instantaneous output overload, and DC voltage in the output.
Context
The PS-1200 was positioned as a large-power variant of the PS-500, offering increased capacity for high-end audio systems. It was designed to improve system performance by delivering stable, low-distortion AC power without the inefficiencies of full AC-to-DC-to-AC regeneration.
Market
Originally priced at ¥500,000 in April 1997, the PS-1200 was noted in 2000 as costing over $8,000. A used unit in mint condition was listed for $2,416.80, modified with an internal tap change to accept US voltage and tested at 100V output without issues.
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