Audio GD Master 10 – Speaker Amplifier Review

First, I want to apologize for the long period of absence I have taken from HeadMania and to thank the readers who did not abandon it. I had a very busy period at work in the last few months and I just couldn’t find the time for any more writing until now.

Introduction

This review is long overdue, as I’ve owned this amplifier since 2 years ago. On the other hand, I’ve had the chance to pair it with quite a few speakers in this time-frame. You can read more about the speakers that I used with it below.

I wanted to make some proper pictures but then, this animal has 40 kg and I remember the last time I had a photo-shoot with it and Xindak (another beast with 52kg). After that photo-shoot I had back pain for 3-4 days :)) .

I can tell you is that the build quality is very good. The chassis is made of thick and sturdy metal with very strong joints between the parts. It also has 2 side handles that are very helpful when you move it around.

With Xindak, moving it around was a painful ordeal, as it the side radiators did not give you any handle room for picking up.  I will use some pictures from the Xindak A600 Review.

Master 10 is on the right:

Specifications and Technology

S/N Ratio	>115DB
Output	250W @ 8ohm 500W @ 4ohm
Output Level (Max)	58V
Input sensitivety	0.775 V RMS @ RCA 1.55V RMS @ XLR 2mA RMS @ ACSS
Input impedance	47K ohm @ RCA 94K ohm @ XLR <10 ohm @ ACSS
Frequency Breadth	20Hz – 20KHz ( + / –  0.01DB )
Channels cross	> -120DB
Channels imbalance	< 0.05DB
Power Requirement	1 Version  100-120V  AC 50/60 Hz 2 Version  220-240V  AC 50/60 Hz
Power Consumption	130W static @240V or 120V
Transformer Power	1600W (4 transformers)
Package Weight	Approximately 40KG
Dimensions	48CM(W)*44CM(D)*19CM (H) (MM, Fully aluminium )
Accessories	Power cord            X1
Operating Temperatures	+5 °C to +40 °C
Operating Humidity	5 % to 90 % (without dew)

You can find all the details on the product’s page.

Some details worth mentioning:

• 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 analog amps .
• 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) and separate power supplies for the right channel and left channels.
• A total of 4 groups of high-quality class A parallel connection PSU’s power the gain stages. To achieve a high S/N, the control circuit is powered with separate regulators.
• Four channel 99 steps digitally controlled relay-based volume control avoids channel imbalance and improves sound quality.
• 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.
• Inputs: 5 analog inputs:  RCA x2, XLR x2, ACSS x1

Listening Impressions and Tests

The most recent tests were performed with   MSB Analog DAC with quad usb, Audio Gd Master 10 and the following speakers  .

• Focal Electra 1028 BE
• Focal Electra 1038 BE
• Martin Logan Theos
• Martin Logan Ethos
• Piega Coax 30.2
• Martin Logan Impression ESL 11A (Review Coming Soon)

Overall it performed very well with most of the speakers above. What I have noticed is that with some speakers it has the tendency to become brutal in the bass section and a little lifeless/bright. But this was only when I did not find the right speaker cables to pair it with it.

And I am  not talking about expensive cables here, unobtanium, you just have to find the right match, depending on the speakers. After that it sounds transparent, smooth and natural and it manages to pull you inside the music.

Bass

The bass section is very good. It hits fast, it’s well controlled and it has very good presence in the sub bass region. It has a good punch, but I would say that it hits faster than with great strength. For example Xindak A600 had an exploding punch, while M10 as a swifter punch.
Overall, it does a great job in this section also showing good detail and textures.

Midrange

This is one of the strongest features of this amplifier. The key aspects of the midrange would be: clean, excellent presence, natural tonality, good details and textures. This amplifier brings the midrange to life, from instruments to voices. Lovely experience.

Treble

This is one of the sections that convinced me to go with M10 instead of Xindak. The treble is extended, smooth, clean and detailed.

With Martin Logan Ethos, sometimes the sound was a little dark, and I’ve heard other amplifiers that managed to bring the treble to life better than M10, but at the expense of midrange presence. Ethos also has unde 0.5ohms in 20khz so this might be an issue, but so does the ESL11A and the treble is quite extended and sparkly on M10.

Overall, the treble perfomance was very good and it’s summarized by the first sentence from this section.

Transparency & Cleanliness

This amplifier is very transparent, as you will hear any change from your sound system, but in the same time, with the correct match, you will get a very clean sound signature. This is one of the cleanest speaker amplifiers I’ve ever heard.

Voices

The voices are superb on M10. They have very good presence, wonderful textures and a very clean / smooth flow. They come out of the speakers and emerge you in the scene.

Transients

The transients are fast. The attack is swift with good, but not great explosion and the decay is fast, but natural (it does not linger nor terminates abruptly).

Natural Tonality

With the right system match this amplifier sounds very natural.

Details

The details are quite good and they come natural in the music. They’re not pushed in front.

Instrument separation/focus

Master 10 has excellent focus around each sound, very clear leading edges, basically leading to great instrument separation & focus.

Soundstage

The soundstage is good, but Xindak showed me that it’s not perfect on M10 and that it could use a little more depth  and more space between the layers.

Conclusions

Audio GD Master 10 is definitely a great amplifier and it managed to stand as high or most of the times even higher than considerably more expensive amplifiers.

I have it since more than 2 years ago and it has been a very good and dependable companion. I’ve paired more than 6 speakers with it and in the end it managed to make them sing beautifully. I am saying “in the end” because I had to find the right match, mostly in the speaker cable department.

Master 10 offers great value for this price and I wholeheartedly recommend it.

Pros:

• Good bass section with good texture, detail and speed
• Excellent clean, natural, detailed with good presence midrange
• Clean, extended, detailed treble
• Transparent/Clean Sound signature
• Excellent vocals
• Natural Tonality
• Excellent instrument separation/leading edges
• Very good  details
• Excellent build quality

Cons

• You have to fiddle around a bit to find the right system match. If you don’t it might sound a little brutal (unfinished in the lower notes and a little harsh on the treble)
• Soundstage is good but it could use a little more depth

 

•