Accuphase copying PS Audio power plants?

Hey guys…

Just came across what seems to be a Accuphase power regenerator…
Here is the link to a japanese web page…You will need to use google translator.

Interesting to say the least.

Best wishes


First I’ve seen of the 1250 but it seems like the next evolution of their waveform correction based power supply they have been producing since the mid 90’s beginning with the ps-500 to the current ps-1230

It will be interesting to see how it differs from their past power supplies and how it resembles PSA regenerators when it hits their site


Hey john2213,

When you click on the link and then use google translator, scrolling down
the page there is quite a description and seems to follow PS Audio technology.

Seems to be more than just an evolution…

here is the english version…from google translate

Manufacturer warranty period 5 years

The power supply is the source of the music played by the audio equipment.
The quality of the power supplied to the audio system is extremely important in improving the sound quality of the audio system.
In 1997, Accuphase launched the “PS-1200”, which supplies clean power with its proprietary waveform shaping technology.
The “PS-1200” compares the reference waveform, which is an ideal sine wave, with the power supply waveform, compensates for the shortfall and removes the surplus to shape the waveform,
creating a clean power supply with little distortion and noise. technology.
It exerts a tremendous effect on the sound quality and image quality of audio and video equipment, and has won high praise.
The “PS-1250” is a large-capacity clean power supply that is the sixth generation, counting from the “PS-1200.”
The “PS-1250” generates a high-precision reference signal without using an oscillator and inputs it to the waveform correction amplifier through balanced transmission
. ,
and achieves a large output capacity of 1200VA at the same time as a low distortion factor.
Furthermore, it has 10 high-quality, safe and reliable hospital-grade AC output terminals that meet strict standards.
The wiring from the output circuit to each AC output terminal is adjusted to the same length, so that there is no difference in sound quality depending on the AC output terminal.
With these functions, it is possible to supply power for your audio system with a single “PS-1250”.
In addition, input/output waveforms can now be observed, allowing you to check the effects of waveform shaping.
They have evolved not only in terms of electrical performance, but also in terms of safety, reliability, and ease of use.

AC constant voltage device based on waveform shaping technology
Waveform correction such as addition and subtraction is performed on the input AC power as it is.
In other words, the main energy source is the input AC power itself, and the loss is only the power for waveform correction.
Therefore, it is more efficient and generates less heat than conventional AC voltage regulators.
Since the power supply frequency depends on the input signal, there is no need to install an oscillator that serves as a signal source, and no high-frequency noise is generated.
The waveform correction amplifier compares the input waveform with the reference waveform, corrects the difference from the reference signal, and converts it into a high-purity output signal.

Low-distortion reference signal generation circuit
Compares the reference waveform, which is an ideal sine wave, with the power supply waveform, compensates for the shortfall, and removes the surplus to supply power with a low distortion factor.
Therefore, the reference waveform must be an ideal sine wave with extremely low distortion.
In the reference signal generation circuit, a comparator detects the zero-cross point of the secondary winding of the transformer for the measurement circuit, and a square wave is generated with a high-precision power supply.
This square wave is first passed through a bandpass filter, then through a 6-stage BEF (band elimination filter),
and then through a bandpass filter to create a low-distortion standard that is not affected by the input voltage. Generate waveforms.
The frequency of the filter switches according to the input frequency, so there is no need to manually switch between 50Hz and 60Hz.
This reference signal generation circuit does not use a PLL (phase locked loop) circuit or the like, so it does not generate unnecessary harmonic components.
A waveform correction amplifier corrects the output of the shield toroidal power transformer S1 winding so that the output waveform approaches this reference waveform.
This low-distortion reference signal generation circuit and powerful output stage achieve a low distortion rate of 0.08%.

Excellent waveform correction ability

Example of correction of distorted waveform
Electric products consume power at peaks and valleys of AC power supply, so the AC power supply at home usually has a distorted waveform like this.
If the crests and troughs of the waveform are missing, the power amplifier will not get enough energy from the AC power supply when it needs a lot of power.
Also, this waveform contains a lot of harmonics that cannot be removed by using filters or the like.
The “PS-1250” has a powerful waveform shaping capability that corrects distorted and insufficient parts to the original waveform.

Correction example of waveform mixed with
noise Relatively low-frequency noise is mixed in the peaks and valleys of an AC power supply.
There may also be pulse-like high-frequency noise mixed in, like sharp thorns.
Filters can remove some high frequency noise, but have difficulty removing low frequency noise.
Even with such an input waveform, the PS-1250 compensates for the shortfall and removes the surplus by comparing it with the reference waveform to generate a clean power supply.

Waveform correction amplifier with excellent power supply capability The waveform
correction amplifier, which performs addition and subtraction of waveform correction, is equipped with a circuit with high naked gain and excellent stability.
This circuit is based on the original pure complementary push-pull differential amplifier circuit that has been installed in power amplifiers for a long time since the founding of Accuphase
, and high-precision and stable operation can be expected.
In the output stage, “bipolar power transistors” with a maximum rating of 15A are used with 20 parallel complementary push-pulls
to supply stable power at all times.

Excellent noise removal and interference elimination ability with three stages The
first stage line filter removes noise components such as digital devices that enter through the power supply line.
The second-stage shielded toroidal power transformer eliminates common-mode noise.
The third-stage waveform correction amplifier produces an extremely clean power supply with waveform shaping.
Moreover, by adopting a negative feedback system, output impedance became very low and the interference of the apparatuses connected to the output is suppressed.
It can be confirmed that the output of “PS-1250” has significantly reduced harmonic components in the audible band.

We locate radiator on right and left and realize ideal heat dissipation structure
Design that is available for high output to up to 1200VA, especially when output power is large, heat generation increases.
By dividing the waveform correction amplifier (with heat sink) into two parts and arranging them on the left and right sides of the chassis, high heat radiation efficiency is ensured, and
stable operation is achieved even at continuous maximum output.

Output power, input/output voltage, input/output distortion factor, and input/output waveform can be displayed on the display. If the capacity is exceeded, the LED blinks and a warning
display shows output power, input/output voltage, input/output distortion factor, and input/output waveform. can be displayed.
Especially for pre-main amps and power amps, the power consumption changes greatly depending on the volume, so you can check the change in power consumption while actually producing sound.
If a device with a maximum output power of 1200VA or more is connected, the LED of the display switching button flashes to warn you.
A circuit protector (circuit breaker) that doubles as a power switch turns off the power switch when the power becomes even higher.

Powerful power output by high-efficiency large-sized shielded toroidal power transformer/large-capacity filter capacitor
All power is output from the power line through the power transformer. Therefore, the power supply section is a very important circuit.
The power transformer uses a large shielded toroidal type with a large power capacity.
A shield transformer is an electrostatic shielding plate installed between the coils on the
primary and secondary sides. Common mode noise on the primary side is sent to the ground by the distributed capacitance between the primary coil and the shielding plate
, This transformer has excellent high-frequency noise elimination capability by preventing high-frequency noise on the side from being conducted to the secondary side.
A toroidal transformer has a doughnut-shaped core that forms a closed magnetic path and has thick copper wires on both the primary and secondary sides
. It is a transformer with characteristics.
In addition, by using a filler material with excellent heat conduction and high anti-vibration effect, it is fixed to an aluminum casting case with a high-efficiency heat dissipation structure, and has excellent characteristics in terms of heat dissipation and anti-vibration effects.
In addition, the aluminum electrolytic capacitor that smoothes the pulsating current that has passed through the rectifier to direct current is
a large capacity 48,000μF/100V high-quality sound type with carefully selected foil materials, etching, and electrolytic solution that emphasize performance and sound quality. We have adopted two custom-made products from , and configured a power supply section with plenty of room.

Equipped with a total of 10 hospital-grade 3P AC output terminals A
hospital-grade 3P outlet is used for the AC output terminals.
These outlets are subject to strict standards for contact resistance, temperature rise, insertion retention force, pressure/heat resistance, impact strength, and insulation.
Equipped with 8 AC output terminals on the rear panel side and 2 on the front panel side, for a total of 10.
In addition, the types and lengths of wires from the output circuit to each outlet are the same, and the AC output terminals to which they are connected are designed so that there is no difference in sound quality.


■ Specifications ■

  • Rated output capacity: 1200VA (continuous output)
  • Rated output voltage: AC100V±1V
  • Rated output current: 12A
  • Output frequency: 50/60Hz (synchronized with input frequency)
  • Output waveform total harmonic distortion factor: 0.08% or less
  • AC output terminals (AC output outlets): 2 front + 8 rear
  • Rated input voltage: AC100V (input voltage range: AC90V to 110V)
  • Input frequency: 50/60Hz
  • No load power consumption: 37W
  • Cooling method: Natural air cooling
  • Display
    ・VOLT-AMPERE: 0 to 1200VA
    ・VOLTAGE INPUT/OUTPUT: AC90 to 110V (green scale range)
    *Display switching button in case of overload LEDs not selected with blink
  • Maximum external dimensions: width 465mm x height 243mm x depth 499mm
  • Mass: 41.8kg

*Specifications and appearance are subject to change without notice for improvement, so please check the manufacturer’s page for the latest information.strong text

Interesting read…
Best wishes