Audio-GD Master 2 MK3
Master 2 MK3 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 2 MK3 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 2 MK3 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.
Drives
Massive use of high power parts and robust power supply guarantee vigorous current output that drives most existing loudspeakers. Master 2 MK3 applies four channels of diamond non-feedback output stages composed of 80 pcs ON Semiconductor transistors, every piece has 15A/230W performance. The capacitance of the whole machine reaches as high as 260,000uF. 4 transformers are used with over power of 1700W.
Shield
Master 2 MK3 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 2 MK3 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.
Highlights
- 30W pure class A, 250W class A at 8 ohm, 1000W at 2 ohm each channel
- Supports XLR and ACSS inputs
- 20 and 26dB two gain modes
- Apply Real balanced ACSS non negative feedback power amp
- Apply "Linear Fidelity" technology non negative feedback output stages
- Soft start power design
- 80 pcs ONsemi (Motorola) output transistors
| SPECIFICATIONS | |
|---|---|
| Output power | > 250W @ 8ohm > 500W @ 4ohm > 1000W @ 2ohm |
| Gain | 20 and 26 DB for selection |
| THD+N (XLR input) | 8 ohm 10W: approximately 0.03% 8 ohm 50W: approximately 0.04% 8 ohm 100W:: approximately 0.05% |
| S/N Ratio | >120DB |
| Input sensitivety | 2.2V RMS @ XLR 2mA RMS @ ACSS |
| Input impedance | 94K ohm @ XLR <10 ohm @ ACSS |
| Frequency Breadth (XLR input) | 8 ohm 1W output : 20-100KHz (-3DB) |
| Channels cross | Mono design without channels cross |
| Channels imbalance | < 0.01DB |
| Power Requirement | 1 Version 100-120V AC 50/60 Hz 2 Version 220-240V AC 50/60 Hz |
| Power Consumption | 250W static @230V (Two units) |
| Transformer Power | >1800W (4 transformers) |
| Package Weight | Approximately 82KG (Two units) |
| Dimensions | Every unit : W(360) H(270) D(457) (MM, Fully aluminium ) |
| Accessories | Power cord X2 |