About the Precision 3 (2020 Edition) :

After the Precision 3S discontinued, there was some customers send emails asked purchase the Precision 3S.
So we decided release the amp again.
We redesigned the PCB board, spent a lot time to adjust the sound performance , removed the DC block caps that improved the sound transparency and bass control character but still sound musical .

About the Precision 3 (2020 Edition) ACSS connect:

The Precision 3 (2020 Edition ) ACSS input support all audio-gd ACSS design headphone amps and preamps but except Master 1 and HE1 .


Cables maybe required:

Standard 2 channel single ended:

        Standard ACSS cable :USD35/pair/1M (For connect to the  ACSS preamp)
        Standard RCA cable : USD48/pair/1M (For connect to any preamp with RCA output)

2x P3 Bridged (Mono) balanced:

        Bridge ACSS 1 to 2 cable : 40/Pair (For balanced ACSS preamp; requires 2x Precision 3 (2020 Edition) in bridge mode, 1 Meter)

        Bridge XLR-2RCA cable: USD68/Pair (For balanced preamp, requires 2x Precision 3 (2020 Edition) in bridge mode, 1 Meter)

 

2X P3 Bi-AMP (Mono) 4 channels:

         Bi-amp ACSS cable 1 to 2 cable : 40/Pair (For ACSS preamp; connect 2x Precision 3 (2020 Edition) working in bi-amp mode, 1 Meter)

         Bi-amp RCA 1 to 2 cable: USD50/Pair (For single-ended preamp; connect 2x Precision 3 (2020 Edition) in bi-amp mode, 1 Meter)

Headphone output cable

          Headphone adapter cable: USD63 (For Precision 3 (2020 Edition) drive single ended 6.3MM headphone, 0.6 Meter)





Summary

Fully discrete design, Non- feedback, current mode ACSS and DC coupled analogue power amplifier
The gain stages and pre-buffer stages all work in class A, built with discrete analogue stages without any opamp or coupling capacitors in the signal channels.
Diamond Cross Non-feedback output stages designed to avoid "switch distortion", rivaling class A amps.
2 analogue inputs: RCA and proprietary ACSS single ended
In total 4 transistors (150W / 15A each). Supports 70W X2 (8 Ohms) output power and 13W X2 (40 ohm headphone)
Power Supply capacity of more than 40,000 uF, powered by oversized transformers
Built with high quality precision 0.1% resistors and WIMA capacitors.
To guarantee cleanest sound and avoid electromagnetic radiation internal metal shielding panels are installed

Sound characteristics:

      We have designed the unit to provide neutral sound and keep the right harmonic distortion to experience a smooth and rich sound.

Please note:

      Read the User Manual page before using the Precision 3 (2020 Edition).
　

Detail of the Current Conveyor Technology

　

Main:

        Precision 3 (2020 Edition) is a discrete design applying the latest ACSS technology which improves the RCA connection to be able to sound as good as the ACSS connection. It seems complex, but in fact it is most straightforward design in the world. There are a lot components in the power supply providing rich and clean sound. The Precision 3 (2020 Edition) power amp has a single “voltage" gain stage to process signals, but works fully in ACSS mode; which in fact is a current gain stage instead of the standard voltage gain stage. The voltage gain state applied by almost all manufacturers requires at least two or three voltage gain stages. We implemented most elementary and shortest signal journey resulting most neutral and cleanest sound.

          Precision 3 (2020 Edition) applies ultra-low distortion single stage ACSS amplifier soldered directly on the motherboard to reduce noise floor even more. The gain stages and pre-buffer stages are all designed to work in pure class A .

         The diamond cross output stage design avoid "switch distortion" as good as the best class A amp.

         The ACSS is a non-feedback technology is designed with discrete amplifiers. Most people think the feedback design offer better specs in test measurements, and non-feedback isn’t as good. Putting the measurements aside, non-feedback offers more pleasant sound for the human's ears. This is a pyridoxal conflict of classic circuits. Our developed ACSS named technology opens a new field: It can offer a neutralsound with very low distortion and high linearity. Retain the dynamics, detail and neutral sound without sounding bright or harsh.

       All signal gain are in current mode, achieved by the unique, superb open-loop multiple output current mirror. Incomparably precise and ultra-low distortion in the gain signal is the result. The signal path is balanced throughout and all transistors work in class A mode.

　

Drives:

        Massive use of high power parts and robust power supply guarantees vigorous current output that drives almost every loudspeaker.
        Precision 3 (2020 Edition) applies two channel diamond non-feedback output stages composed of 4 transistors, every transistors can handle 150W / 15A . The power supply capacitance is over 40,000uF.


        The Precision 3 (2020 Edition) have very wide frequency band with excellent phase distortion, and boost the amp to have excellent detail and  dynamic reproduction.


Inputs:

       Precision 3 (2020 Edition) has RCA single ended inputs and top grade proprietary ACSS current signal inputs. No matter what kind of signal it is input .



Components:

        Solely audiophile grade components being used, e.g. 0.1% resistors, WIMA caps, and custom ordered NOVER (UK brand) caps.