- 2500mW Pure Class A Headphone Amp & Pre-amplifier
- Audio-gd in-house developed ACSS technology
- Non-Negative Feedback design
- Full Discrete Transistors Design
|Improvement may result in changes in specifications and design without notice.|
|S/N Ratio||>125dB (Volume minimum)|
|Gain||Gain L : +14dB |
Gain H : +20dB
|Headphone amp Output Power |
( Pure Class A )
|25 ohm: 2500mW |
40 ohm: 1600mW
100 ohm: 650mW
300 ohm: 325mW
600 ohm: 160mW
|Preamp Output Level (Max)||8V @ RCA|
|Input impedance||47K ohm @ RCA |
<10 ohm @ ACSS
|Frequency Response||20Hz – 20KHz |
( +/- 0.3DB )
10Hz – 125K
|Power Requirement||1 Version 100-120V AC 50/60 Hz |
2 Version 220-240V AC 50/60 Hz
|Power Consumption||20W @240V or 120V|
|Package Weight||Approximately 3.5KG|
|Dimensions||W240 X L360 X H80 (mm, black aluminum )|
|Accessories||Power cord X1|
There are a lot different quality DACs. They had different design and output impedance . To avoid negative effect on sound quality by differences in DAC’s output impedance, in the A-2, we have design a pair diamond differential buffers in the input . All the RCA input signals go through these buffers, the output impedance become very low, even if the source have high or low output impedance.
The diamond differential buffers working in pure class A , and it has a short signal journey. this way we can keep the sound quality without coloration ,(dry and harsh) .
CLASS-A ANALOGUE OUTPUT STAGES
The A-2 have in its design a pare diamond differential output stages.
The output stages have two pairs of 20W transistors offer 2500MW at 25 ohm Class A ,drive most headphones (work in pure class A ) ,no matter if you have low sensitivity headphones
ACSS – Current Amplification
Audio-GD has developed an advanced current-driven amplifier technique. Also known as ACSS, Audio-GD Current System Signal. This special technique ensures that the signal travels a much shorter path and that ensures a more transparent, faster and more neutral reproduction. A similar technique is used by, for example, KRELL. The Current Conveyor technology mostly components are the current mirror. The Current Conveyor technology isn’t a new technology, at 1966 , professor K.C. Smith and A.S.Sedra publish the concept “current mode analogue circuits “ .
HIGH PRECISION VOLUME CONTROL
Volume control is accomplished by a hi-graded ALPS-27 potentiometer.
The DAC consist of A tuned low noise, low flux leakage, R-cores transformer. In total 65W power to supply all digital parts and the left and right analog boards. The DC power is distributed separated power regulators. All are pure class A low noise shunts; fed by linear power supplies. Resulting in ultra-high speed and clean power for all individual parts.