Audio-gd :: Master-2HReal Balanced ACSS Non Negative Feedback Power Amp, Supports XLR and ACSS inputs, Applied "Linear Fidelity" Technology, Soft Start Power Design, 80 pcs output transistors
Price: 4366.40 EUR ( 3549.92 EUR Net Price)
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Audio-gd Master-2H

Master-2H (Since 2015 July 15th)#

Real Balanced ACSS Mono Power Amp
  • Supports XLR and ACSS input
  • 80 pcs MJL4281/4302 as output transistors

Main features

  • Fully balanced design, the gain stages and pre-driver stages work in class A and are built with discrete analog stages without any OPA or coupling caps in the signal channels.
  • The output transistors stages work in high idle current state . The Diamond Cross output stage design avoids "switch distortion" as good as class A amps.
  • Non- feedback ACSS analog amps.
  • 2 group analog inputs: XLR / ACSS
  • Applies 80 pieces of ON Semiconductor “the King of transistors” MJL4281/4302. Supports 250W X2 (8 Ohms) output.
  • The capacitance of the whole machine reaches as high as 260,000 uF, Two 800W (Total 6000W) core transformers and two R core transformers , Separate power supplies for the right and left channels.
  • A total of 4 groups of high-quality class A parallel connection PSU's supply the gain stages.
  • Applies all audiophile grade components, including DALE resistors, WIMA caps, custom order NOVER (UK brand) caps, all audiophile grade input & output sockets and gold IEC socket. Applies the round-corner style chassis which has lower syntony, or vibration. Between the transformers and signal amps resides a thick metal board to avoid disturbance.

Audio-Gd Master-2H


Master-2H is a true balanced design applying the newest ACSS design which can improved the XLR connection to sound as good as the ACSS connection. It seems complex , but in fact they are the most simple design the world has ever had , their a lot components to process the power supply. The Master-2H power amp only has a single " voltage" gain stage to process signals, but works in ACSS mode so in fact it is a current gain stage instead of voltage gain stage, whereas normal OPA chips already include two or three voltage gain stages. The simplest and shortest signal journey brings out the most neutral and least colored sound. Master-2H applies ultra-low distortion single stage ACSS amplifier and soldered directly on the motherboard . The gain stages and pre-driver stages working on class A . The output transistors stages working on high idle current state. The diamond cross output stage design can avoid "switch distortion" as good as the class A amp. The ACSS is a non-feedback technology made with fully discrete amplifiers. Most people know the global feedback design can offer better specs in test measurements, and non-feedback can't do well in test measurements but can offer better sound for the human's ears. Here is a conflict of the classic circuits. But the ACSS opens a new field, it can offer a least coloration sound which is more neutral with very low distortion and high linearity. So it can retain the dynamics, detail and neutral sound but not sound bright or harsh. All signal gain is in current, 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. The ACSS parts use 4 groups of high-quality class A parallel connection PSU for dedicated DC supply. The class A parallel connection PSU has very high input impedance to avoid pulse from the PSU from affecting the gain stages, and low output impedance with very fast speed and high linear, so it is a very clean power supply.

Audio-Gd Master-2H


Massive use of high power parts and robust power supply guarantee vigorous current output that drives most existing loudspeakers. Master-2H applies four channels of diamond non-feedback output stages composed of 80 pieces of “the King of transistors" MJL4281/4302. The capacitance of the whole machine reaches as high as 260,000uF. Four transformers are used with total power of 1700W.

Audio-Gd Master-2H


Master-2H uses heavyweight all aluminum alloy chassis to prevent the eddy current of transformers from interfering with the circuit board. The interior is separated into 3 sections with aluminum boards for the best separation off the ACSS parts, the output stages and transformers. The AC power wire is shielded by a copper channel from back to front. Master-2H take care the vibration for the best sound playback. Each channels gain parts under a 5MM thick aluminum board, these aluminum board not only poise the heat between cool and hot amps, our workers care to install all transistors cling the aluminum board for avoid the vibration cause the sounding worst. From our testing, with the aluminum board bring clear detail reproduce and less harsh than take off the aluminum board .

Audio-Gd Master-2H


Uses all audiophile grade components, including DALE resistors, WIMA & SOLEN caps, custom order NOVER (UK brand) caps, all audiophile grade input (Neutrik) & output sockets (CMC) and gold IEC socket. The output transistors are 80 pieces of “the King of transistors” MJL4281/4302. Master-2H has all parts of four channels exact-matched before installation.

Audio-Gd Master-2H