REVIEW HFA – Audio GD R8 DAC, Master 1 preamp, Master 3 power amp
- True Balanced Design
- ACSS – Non Negative Feedback
- “Linear Fidelity” Technology
- Soft Start Power Design
“Linear Fidelity” Technology (Patent Pending)
The Master 3 output stages are using spectacular technology developed by Audio-GD in-house and is referred as “Linear Fidelity”. (patent pending) The output stages have zero negative feedback, which normally means increased and unwanted distortion.
Most power amp designs show increased distortion when the output level increases. The full frequency band’s distortion level increases even more, specially the low and high frequencies. The special Audio-GD “Linear Fidelity” technology can keep the distortion low and steady at all levels. This results in ultra linear performance.
The ultra low distortion of this non-negative feedback amplifier is achieved by its ultra linear behavior of the amplifier. This results in a very transparent and analogue sound stage.
- True Balanced ACSS Power Amplifier
- Fully balanced design, the gain stages and pre-driver stages working on class A , built by 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 well as class A amps.
- Non- feedback ACSS analogue design
- Installed 24 pieces transistors: “the King of transistors MJL4281/4302”
- Supports 250W X2 (8 Ohm) output & 500W x2 (4 Ohm).
- The capacitance of the whole machine reaches as high as 140,000 uF, with two 750W circle core and two R cores transformers (Total 1500W)
- Completely separated design, separated power supplies for the right and left channels.
- In total 4 groups of high-quality class A parallel PSU’s to power gain stages. To achieve a high S/N, the control circuit is powered with separate regulators.
- Audiophile grade components, including DALE resistors, WIMA caps, custom order NOVER (UK brand) caps, all audiophile grade input & output sockets and gold IEC socket.
- ACSS (XLR 4-PIN)
- 2 x Speaker (LEFT & RIGHT) Neutrik output IEC sockets.
MASTER 3 is a discrete design applying the latest ACSS technology which improves the XLR connections to be able to sound as good as the ACSS connections. 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
MASER 3 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. MASTER 3 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 isnt as good. Putting the measurements aside, non-feedback offers more pleasant sound for the human’s ears. This is a pyramidal conflict of classic circuits. Our developed ACSS named technology opens a new field: It can offer a neutral sound 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.
Massive use of high power parts and robust power supply guarantee vigorous current output that drives most complex loudspeakers. Master-10 applies four channels of diamond non-feedback output stages composed of 24 pieces of ON Semiconductor transistors . The capacitance of the whole machine is over 140,000uF. Two enormous transformers are used with total power of 1500W as well as 2 R-Core transformers to power the pre-stages section
|2x250W under 8 Ohm / 2x500W at 4 Ohm
|Switch Class A / Class AB
|Class A up to 10W at 8 Ohm / Class AB from 10 to 250W at 8 Ohm
|94K Ohm (XLR) / <10 Ohm (ACSS)
|20Hz – 20kHz to 0.01dB
|2x XLR / 2x ACSS
|2x HP Stereo Terminal Blocks
|4 transformers, including 2 R-Core for 1500W
|480 x 440 x 190mm
|1x Power cable