The Master 2A (M2A) are 100W pure class A mono power amplifiers. As a result, they can become very hot (50 degrees) and natural ventilation is necessary for cooling.
TECHNICAL HIGHLIGHTS
- Pure Class-A 100W at 8 ohm; Total 150W at 8 ohm / 600W at 2 ohm
- Real Balanced ACSS Non-Feedback Power Amplifiers
- Supports XLR and Audio-GD ACSS proprietary inputs
- “Linear Fidelity” design (patent pending)
- Soft Start Power Design
- 80 (!) output transistors per channel
Master 2H vs. Master 2A
Master 2H is a power amplifier which has a completely neutral sound characteristics. Both ACSS / XLR inputs produces neural sound.
Master 2A is a 100W pure class A amplifier , the pure class A design produces a warmer and smoother sound and is not completely neutral. Although the ACSS inputs of the Master 2A are more neutral compared to the sound of the XLR inputs which are warmer and smoother.
OFFSET DC FILTER
The mains should provide pure AC voltage of 230 volts, but that is not always the case, one problems with mains is the DC offset. The new built-in DC Blocker will filter and correct this up to a maximum of 1.2 Volt which is sufficient for the mon power amps. Buzzing of the transformers will be minimized.
INPUTS
- 1. XLR
- 2. ACSS (XLR 4-PIN )
OUTPUT
- Speaker Neutrik output IEC sockets.
“Linear Fidelity” technology
The Master 2A has special “Linear Fidelity” technology designed output stages . The output stages are designed without negative feedback but can keep the distortion very low and has an excellent ultra linear performance. On many power amp designs the output power determines the amount of distortion. Even when measuring a specific output power, the distortion level of the full frequency band already has a significant difference.
The blue line shows a frequency at 8 ohm 20W output of a well known power amplifier of round USD10k.
Different types of distortion also affect the sound. For example, if you are playing a piano, you can hear the difference between a brand A piano or a brand B piano due to the different distortion on the frequency band.
The more lifelike the rendering, so the better this distortion remains intact, the better you can perceive the differences between the A and B brands.
NON-FEEDBACK DESIGN
The applied negative feedback is done to reduce the distortion of an amplifier. A disadvantage of an amplifier with negative feedback is that it reduces distortion but also makes listening unpleasant. Also, the negative feedback power amplifier often has a good distortion result when measured with an ideal emulation load, but with real speakers, the electrical potential from the speaker through the feedback loop to the amplifier’s input stages can actually cause greater distortion.
The negative feedback power amp reduces the distortion, but the distortion increases as the output power increases, making the larger dynamic music sound loud and fire in your face while listening to the music.
Usually the non-negative feedback design has high distortion and is difficult to control, especially driver output stage operating under strong current condition. In our Master 2A design, the gain stages adopted ACSS technology, it is the design without negative feedback, but the original advantage of the very low distortion remains.
SPECIFICATIONS
Improvement may result in changes in specifications anddesign without notice. | |
S/N Ratio |
>110DB |
Gain | +26 DB |
Output | >100W @ 8ohm Class-A >150W @ 8ohm >300W @ 4ohm >600W @ 2ohm |
Input sensitivity | 2.2V RMS @ XLR 2mA RMS @ ACSS |
Input impedance | 94K ohm @ XLR <10 ohm @ ACSS |
Channels cross | Mono |
Channels imbalance | < 0.01DB |
Power Requirement | 1 Version 100-120V AC 50/60 Hz 2 Version 220-240V AC 50/60 Hz |
Power Consumption | 600W static @230V |
Transformer Power | 1800W (4 transformers) |
Package Weight | Approximately 70KG |
Dimensions | W(340) H(260) D(450). (Each channels) (MM, Fully aluminium ) |
Accessories | Power cord X2 |
GRZEGORZ CELITAN –
Hi audio fans ,
I have had the A-GD Master 2A monoblocks for about three years now and all that the producer claims is true. Meaning that the sound is very detailed and rich in microdetails from any source that is put in . I am driving them with the Audio-GD HE1 preamp which is btw also a hi-end preamp. One thing that it only lacks is a phone (cartridge MC/MM) input. I wrote to AUdio_GD and gave a hint that it would be great if they’d design an preamp with such an input politely they wrote back that they would consider it for the future plans and that they are now focused on the digital source than analogue,
Back to the MASTER 2A well I have compared them with a hi-end AMP2 made by Acoustic Arts and they are very close to the sound of that big class A amp by Acoustic Arts but the Master 2A are a bit warmer in sound and that for my subjective hearing is very good. My set-up is as I wrote
Pre-amp : AudioGD HE1
AMPS: Audio GD Master 2A
source : Esoteric DV50 (SACD/CD /Audio DVD/ DVD player
Floorstanders: Project by Troels Graversen DTQWT mkIII ( ~ 6ohms/ 94dB)
nalogue source: THECNICS SP10 with SME 3012 Cartridge KOETSU Black connected to HE1 by a setup trans.
I use the ACSS kable from A-GD to connect withe amps and to me it is a bit better than XLR but far better than single end RCA kables (VDH First).
My speaker cables are VDH Revelation.
Bear in mind that this is all my own subjective hearing but many friends that come over to listen to music (mainly Jazz / Rock/ chillout are just astonished by the sound that the set-up makes.
I also campared the Master 2A amps to a Tube amp single end 845 and although the tube amp is warmer in sound and great but does not have the control of bass that the Master amps have. Bottom line :
Great amps for a reasonable cost
Hi-end sound
Dead silient(no hum)
Look great (but only black color)
Also bear in mind that an amplifier is as good as the rest of components but if you are willing to pay over 5k euros just for amps I am sure that all other gear is as good as well.