{"id":17401,"date":"2019-03-31T09:26:58","date_gmt":"2019-03-31T07:26:58","guid":{"rendered":"https:\/\/www.hifi-advice.com\/blog\/?p=17401"},"modified":"2021-09-13T10:19:25","modified_gmt":"2021-09-13T08:19:25","slug":"audio-gd-part1","status":"publish","type":"post","link":"https:\/\/www.hifi-advice.com\/blog\/review\/digital-reviews\/spdif-dac-reviews\/audio-gd-part1\/","title":{"rendered":"Audio GD R8 DAC, Master 1 preamp, Master 3 power amp, and Magna Hifi ACSS cables"},"content":{"rendered":"

Review samples supplied by Magna Hifi<\/a>
\nRetail prices can be found after the conclusion<\/h4>\n

Ten or so years ago, most equipment from the Far East was known for being cheap and having been made to low production standards. Well, that has changed. Of course, there are more and more European and American companies outsourcing their production to the Far East but I’m talking about serious hi-fi that is not only fabricated in China but also designed there. I’ve now come across several Chinese brands that make high-quality products that compete with much higher-priced European or American competitors. As it would turn out over the course of this review, Audio GD is one such brand.<\/p>\n

Prior to this review, I was not familiar with the Audio GD brand. When I asked Jos Schellevis of Magna Hifi about their price brackets he responded that it might be more interesting if I would review them not knowing their prices. He was absolutely right and so I refrained from looking them up until after having formed my opinions and, contrary to my usual method, I will not mention the prices until the end of this review. I will disclose that when I did\u00a0look up the exact prices later, I was very<\/em> pleasantly surprised!<\/p>\n

Magna Hifi<\/h3>\n

Led by Jos Schellevis and Rob de Brouwer, Magna Hifi is not just a selling point, they also have their own servicing department that handles repairs as well as modifications and upgrades. They also develop interesting audio components such as the I2S Mano streamer and they offer their own line of cables, including the ACSS current cables, which are similar to, and compatible with, Krell CAST. Naturally, Magna Hifi can supply any component that you like, but to make it easy for the consumer, they pre-selected precisely those components from the lineups that were liked most, that offer the best price\/performance ratio, and which work most synergistically with each other.<\/p>\n

Magna Hifi was created due to the limitations of the musical characteristics of a popular media streamer. Because both Rob and Jos have an electronics background and both also work at a high-tech hardware and software company, it was no surprise that the streamer was quickly found in parts on the desk. The improvements that they implemented were pivotal and that made them decide to set up Magna Hifi. They’ve since grown into a distributor and reseller of, among others, Audio-GD, Holo Audio,\u00a0and Singxer.<\/p>\n

ACSS<\/h3>\n

Perhaps the most well-known manufacturer to use a similar technology is Krell, who applied the Current Conveyor Technology in their products called \u201cCAST\u201d, which stands for \u201cCurrent Audio Signal Transmission\u201d.<\/p>\n

In Japan, there are a few products based on Current Conveyor Technology that they call \u201cSATRI\u201d. In Audio GD products a similar Current Conveyor Technology is applied and to avoid conflict, it is called \u201cACSS\u201d, which stands for \u201cAudio-GD Current Signal System\u201d.<\/p>\n

In short: these technologies enable signal transfer via current, rather than via voltage, which is helpful for two reasons. First, it enables very simple circuits and simple is nearly always better. Second, current conveyance is unaffected by the non-linearities that are inherently present in transistors.<\/p>\n

In the Audio GD application, ACSS technology is not only applied in the analog field but also in digital signal transmission such as with transports and digital converters. While CAST, SATRI, and ACSS are all forms of Current Conveyor Technology, their implementations are different. Although the three formats use different connectors, Audio GD ACSS products work just fine with KRELL “CAST” and SATRI products. For a more detailed description please head to the Audio GD website.<\/p>\n

The current-driven ACSS connection method is compatible with Krell CAST. However, Krell amplifiers have lower gain compared to the Audio-GD Master series amplifiers when using the CAST connection. To address this, customers can custom order the Master 1 to have higher ACSS output gain if expecting to connect to Krell amplifiers.<\/p>\n

After the assessments of the components, I will dive into the audible differences between Audio GD ACSS cables and Magna Hifi ACSS cables, as well as compare them to a range of my usual cinch and XLR cables. Here I’d like to point out that the ACSS method is no gimmick. The Audio GD components absolutely sounded their best when using ACSS, and better than with any of the cinch or XLR cables that I have at hand, and that includes very pricy ones.<\/p>\n

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Appearance and Service<\/h3>\n

The Audio GD products have a clean and purposeful, simple appearance, with a build that is reminiscent of Ayon products, albeit with all screws in sight, and, on some models, protruding (sticking out), rather than being flush. To address this and make for a cleaner appearance, Magna Hifi offers a service to replace all the protruding screws with flat, flush-mounted types. That kind of service is another upside of purchasing from Magna Hifi.<\/p>\n

Components under review<\/h3>\n

Reviewed here are the Master 1 preamp, R8 DAC, and Master 3 power amp that will be used as a complete system as well as independently, and will be compared with a range of other components. All three components are true balanced designs and all are capable of being connected via ACSS, which is a current-driven connection, similar to, and compatible with, Krell CAST, as well as via cinch and XLR. The signal-carrying circuits are built exclusively using discrete components and no SMD components and no Op-Amps are applied in the analog section. Heavy emphasis has been placed on the power supplies, the preamp using 3 R-core linear power supplies with 9 stages of regulation and the DAC using no less than\u00a021 low-noise regulation stages. According to the official specs, all parts and components are selected based on sonic performance as well as technical measurements and in all cases,\u00a0high-grade parts and exactly matched transistors are used throughout. Looking at the circuit boards, their layout, and how they are populated, it is clear that these products really are built with great care.<\/p>\n

Running In<\/h3>\n

Because all the components were still new, I kicked off my listening sessions by using all three components together, all interconnected using ACSS cabling and let them acclimatize for over two weeks by being switched on all the time and playing music as much as possible while assessing the intermediate performance now and then. I found that while the DAC and preamp were very quick to settle, the power amp took by far the most time to perform its best and fill out tonally, going by my findings at least a week of continued use, with further smaller gains beyond that.<\/p>\n

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Audio GD System Performance<\/h3>\n

Although we’re only at the beginning of this review and I will dive deeply into the three components’ individual qualities further down, I will jump the timeline, straight to later in the reviewing process, to comment on these component’s performance as a complete system, using all Magna Hifi ACSS connections: it’s simply impeccable! With this system driving the Kroma Audio Carmens<\/a>, I was entirely happy. This was a performance that bordered on what’s normally possible only by using reference-class equipment that carries multiples what the Audio GD system costs. Was there nothing to nitpick, then? Sure there was, and I’ll get into that in the next two parts of this review, but the point is that the combined delivery was so natural and transparent and so convincing and engaging that I could just relax with it and enjoy whatever I played. And never did I have the feeling that I was being shortchanged in any way. Given the level of components that I am used to listening to, that is quite an achievement. Although the components themselves are of course mainly responsible for this, as would become clear later, a sizable chunk of the performance came from using ACSS cables throughout, further making a case for the system approach.<\/p>\n

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Audio GD Master 1 Preamp<\/h3>\n

The Master 1 preamp has a sleek profile but is just as deep as it is wide (43cm). It’s not without reason: the Master 1 is actually filled with electronics all the way from the front to the back. Personally, I like these dimensions but you may want to make sure that your rack has enough space. Functionally, this is a straightforward component with two buttons for input selection and two for volume level and a power switch completes the controls. Although I really like its simple looks, the real beauty is within.<\/p>\n

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Since the preamp is fully balanced, it contains two amplifier stages per channel that work together, one in normal phase and the other in reverse phase. When setting the volume, this means that 4 channels need to be adjusted simultaneously. Audio GD raises a very fair point in stating that\u00a0Quality of volume control is very important in balanced applications. The four channels have to work synchronously to keep the balanced signal in perfect shape. Many manufacturers apply off the shelf integrated chips to take care of this and although that works very precisely, it is argued that these components leave a sonic imprint on the sound. Stepped attenuators using discrete resistors, for example, are found to be purer and more direct, although some others claim that those resistors also have a certain sonic character. That subjective matter aside, arguably the purest and most direct approach to volume controls, while retaining full convenience, is what Audio GD have implemented here: high-precision\u00a00.05% tolerance film resistors that are switched by gold-contact-relays.<\/p>\n

I first encountered such a volume control in the Jeff Rowland Consonance<\/a> and Sphinx project 8 preamps and it seems that this method is hardly used anymore but I am glad to see its return here. The Master 1’s volume control has 99 1-dB steps which works just like a chip-based volume control and comes along with reassuring clicks for every change in volume.\u00a0There are 2 XLR inputs, 2 cinch inputs,\u00a0and 1 ACSS balanced input. Outputs are provided as cinch, XLR, and balanced ACSS.<\/p>\n

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Main system with CH Precision<\/h3>\n

To really put the Master 1 preamp to the test, I inserted it between the 40K\u00a0CH Precision C1 DAC<\/a> and\u00a0 33K\u00a0A1.5 power amplifier<\/a>. ACSS was not possible in this isolated setup so I used a variety of interlinks, including the Cardas Clear<\/a>, Vermouth Reference<\/a>, and Final Touch Audio Ganymede<\/a>.\u00a0Naturally, that means comparing a system without a preamp to one that includes one which is far from fair but nevertheless, it’s a good way to test the preamp’s transparency. Now, I should state upfront that not one preamp that I tested so far has proven to be truly and utterly transparent. In all cases, you can hear it clearly when a preamp is in the signal path. Not even the 30K\u00a0Jeff Rowland Corus + PSU<\/a> was inaudible. In analog preamps, therefore, I tend to look for subjective<\/em> transparency and overall even-handed performance as well as its performance relative to other preamps, which I will get to further below. In an absolute sense, what I heard after inserting the Master 1 between C1 and A1.5 was impressively even-handed, unfiltered, and neutral, but it did not pass the signal fully untouched. However, whereas some preamps, even very expensive ones, round off the transients, thicken the bass, color the sound, or even add a synthetic touch, the Master 1 did none of those things.<\/p>\n

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The only sin that it committed was a reduction in the overall resolution, audible mostly in the hi-hats, which lost some of the expression and differentiation of the individual strokes that these sounds are made up of, sounding more washed over, rougher, more like global whooshes, compared to listening without a preamp. But even if it reduced the transparency in an absolute sense, still, it sounded<\/em> essentially very neutral. And, importantly, in spite of its neutrality, the Master 1 never sounded clinical, let alone hard or harsh, the overall sound was actually very natural.<\/p>\n

The Master 1 preamp was very revealing of the cables used to connect it. Although it certainly sounded most impressive when connected via ACSS, depending on the required balance it worked well with all the aforementioned XLR and cinch cables and arguably provided the most refined sound using the Cardas Clear of Final Touch Audio Ganymede.<\/p>\n

At this stage, if I did not know better, I’d say that this preamp had a 4000-5000 price tag.<\/p>\n

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Secondary system with Ayon<\/h3>\n

Then, for a much fairer comparison, I took the Master 1 to the second setup, in which it was compared to the 7K\u00a0Ayon Stealth<\/a> preamp. The speakers in this setup are Xavian Perla Esclusiva<\/a> and the power amp is the NuPrime ST-10<\/a>. As a DAC I used the super hi-res\u00a0Aqua Formula xHD<\/a> and the interlinks between all the components were all AudioQuest Water<\/a> cinch versions. Compared to the Stealth, the Master 1 is lighter\u00a0in balance but actually very similar in resolution and refinement. Here, I did not notice a difference in treble differentiation at all, further confirming the relativity of the aforementioned tests using the main CH system.<\/p>\n

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The Ayon is a tube design, one that sounds very bold and colorful and with a tonally rich midrange and I love it for that. It works a treat in this setup and pretty much anywhere else that I tried it. But I wouldn’t call it very neutral.\u00a0The Master 1 is considerably more transparent and a lot cleaner and therefore truer to the source. Just like in the main system, the Master 1 has an even-handed and highly neutral sound that injected no discernible character, subjectively in this setup sounding pretty much as if no preamp was present at all.<\/p>\n

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As inescapably tends to happen with very neutral transistor-based components, the Master 1 did not possess the euphonic midrange magic and free-flowing soundstage abilities of the tube-based Stealth but, importantly, neither did it make the music mechanical and certainly not analytical, the presentation remained natural. Moreover, after having listened to the Master 1 for some time and going back to the Ayon, the latter sounded quite bassy and uneven, further highlighting the neutrality of the Master 1. After some time, though, you got used to its specific tonal deviations again and its tube magic wins me over.<\/p>\n

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Although the Ayon’s character fits this system very well and I happen to like its bold and colorful presentation, the Audio GD Master 1 is easily more neutral and definitely more revealing of the source. Oh, did I mention that the Ayon is 7K? Well, the Master 1 is A LOT less than that.<\/p>\n

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Audio GD Master 3 Power Amp<\/h3>\n

Of the three components, the Master 3 power amplifier is visually the most impressive. Big and heavy and constructed from thick aluminum panels, it reminds of classic high-end power amps. It\u2019s not only taller than the slim source components but at 48 cm it is also wider. It weighs 40KG but thanks to the clever crossbars that are positioned along the cooling fins, it is a lot easier to carry and position than amps with similar weight and no handles.<\/p>\n

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Like the other two components, this is a true balanced design, meaning that there are 4 amplifiers built into the chassis. Although all power amplifiers employ preamp gain stages that work in voltage mode and power output stages that work in current mode, it seems that the Audio GD Master 3 takes this one step further. Like the DAC and Preamp, the power amp offers ACSS connections but apparently applies the underlying circuit to the entire amp. The below official info, slightly paraphrased, may well be an explanation for why I found the differences between XLR cables and ACSS cables to be less spectacular than with the DAC and Preamp.<\/p>\n

\u201cThe Master 3 power amp has a single \u201cvoltage” gain stage to process signals but works fully in ACSS mode which 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 \u2026 which improves the XLR connections to be able to sound as good as the ACSS connections. It seems complex, but in fact, it is a\u00a0most straightforward design \u2026 We implemented the most elementary and shortest signal path resulting in the most neutral and cleanest sound.\u201d<\/em><\/p>\n

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With manufacturer-supplied figures of 250W in 8 ohms and 500W in 4 ohms, the Master 3 does the power doubling trick which is often seen as the holy grail in amplification. In practice, not many amps can claim to be able to do this. The doubling of power means that the power supply is very stable which allows the amp to control “difficult” speakers more easily while retaining unfettered output even in uneven impedance characteristics. With a total of four transformers (2 Toroidal for the current stage, 2 R-Core for the voltage stage) amounting to over 1500 watts, followed by 140,000 uF of capacitance, fed into four independent outputs with a total of 24 ON Semiconductor transistors, there is no doubt that this is a very potent amplifier. The manufacturer claims that this amp\u2019s vigorous current output drives most complex loudspeakers and again I have no doubt about that. All the gain stages work in Class A and the power output stages work with \u201chigh idle current\u201d, indicative of a high bias, Class A\/B design. In use, and with the speakers that I had at hand, the amp only ever becomes hand-warm, never hot. The output stages have zero negative feedback and are DC-coupled, built using all discrete components, so without any Op-Amps. The output stages use a proprietary technology developed by Audio-GD which is referred to as “Linear Fidelity” (patent pending). It is not disclosed how this circuit operates precisely but the aim is to avoid distortion that normally goes hand in hand with zero feedback designs.<\/p>\n

Very powerful amplifiers can sometimes be the aural equivalent of a heavy luxury car with an oversized engine, meaning that they can have plenty of torque but not so much the agile behavior of a sports car. In other cases, very powerful amplifiers can sound overly controlled, especially when driving efficient speakers. Fortunately, neither of these scenarios apply to the Master 3. This amp is absolutely not slow and neither is it over-controlled, it really is superbly balanced. Although I understand that it is not possible to truly remove all forms of feedback from an amplifier design, I\u2019ve listened to more than a couple of low-feedback designs and designs that only use local feedback. In general, what these bring is a naturally free-flowing sound. Alas, in most cases, however, I also find that the tightness of the bass and to some extent the rhythmic performance are sacrificed in the process. This again is something that absolutely does not happen with the Master 3. This amp has tight, articulate, and very fast bass.<\/p>\n

Sound<\/h3>\n

Do note that cold from the box and prior to the running in, the Master 3 not only sounded thin, but it also lacked bass pressure and was devoid of tonal color. One week of playing time did a lot for the bass grip and the tonality also further filled out after that.<\/p>\n

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So, how does the Master 3 power amp sound when it is on song? Well, it doesn’t really have a sound at all! As mentioned, it is fast and articulate yet not analytical. It is also extremely neutral and very linear. The amp simply does not add any character to the sound. The main aspect that stands out for me of the Master 3’s delivery is its bass, which is on the lean side. In spite of its huge power reserves, this is not a thunderous-sounding amp. But that’s probably for the better because very beefy sounding amps don’t usually excel in pace and rhythmic precision and that is precisely where the Master 3 does<\/em> excel. If I did not know any better then I’d assume that it had a switched power supply, it really is that<\/em> nimble and fast. If there was anything that I could criticize about this amp’s delivery on its own, in the context of my usual system, it would be that it can be a little bit restrained dimensionally, as well as in terms of expression. Then again, amps that do all that the Master 3 does and<\/em> add these last requests simply don’t come in a price category that is anywhere near comparable.<\/p>\n

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Vermouth Reference and Audio GD ACSS cables<\/em><\/p>\n

Although the differences between XLR cables and ACSS cables were indeed less pronounced than they were with the DAC and Preamp, I still found the amp to sound best using ACSS. A good second place, in this case, was for the Vermouth Reference XLR cables which added more heft and impact to the amp’s sound.<\/p>\n

Comparisons<\/h3>\n

Given the ginormous<\/em> price difference, my next comparison is ultra-unfair. But, as always, I figured “why not?”<\/em> and proceeded anyway. The 33K CH Precision A1.5<\/a>\u00a0does not have a very voluptuous sound itself, it is, first and foremost, a very, very, neutral amp. Hey, the Swiss practically invented<\/em> neutrality! The interesting thing is that the Master 3 has a similarly neutral and even-handed balance although it is a little bit leaner still in the bass.\u00a0The Master 3’s treble performance is also quite remarkable. It does not stand out in any way, being as articulate, airy and precise as it needs to be, neither hard nor washed over, not sticking out nor rolled off. Truly, not many power amps, especially not the ones as powerful as the Master 3, deliver this kind of treble performance. Apart from the bass, the most outstanding difference between these two amps is in terms of resolution and finesse, the A1.5 being considerably more resolving and subtle. And that’s fair enough, given that it is over 10 times more expensive than the Master 3.<\/p>\n

Another amp that is on visit for a review is the Naiu Laboratory Ella. A switching amp using bespoke technology, one might assume it to sound like something based on ICE power- or perhaps Pascal modules. The contrary happens in this case, the Ella sounding warm and smooth with sonorous, super-solid bass, all in all more like class A than class D, in fact. At 8K, the Ella\u00a0amp is not cheap but also not outrageously expensive. Where does this place the Master 3, you might ask? With the Ella’s smoothness and the Master 3’s neutrality, the two amps have very different presentations. When I focus on the refinement and resolution, I’d rank them as being equally great. For good measure, neither is able to approach the extremely refined CH Precision A1.5, but both are still easily hi-res enough to be quite revealing of the source components. In addition, although the Ella sounds sweeter and has very natural treble behavior especially for a switching amp, the Master 3 is actually texturally more fleshed out, especially in the midrange. It’s a kind of inner resolution and harmonics that is something that I often find is better with class A\/B designs than with class D designs.<\/p>\n

While the Master 3 worked well with all the cables that I tried, of the regular XLR cables, the Vermouth Reference provided the most powerful and sonorous balance that I found most attractive. The Magna Hifi ACSS cables provided a less sonorous and solid but more natural, refined and free-flowing sound, however, that only works with the other equipment that has ACSS (-compatible) connections such as Audio GD equipment. But I’ll dive deeper into this in part 3 in the section ACSS Sound.<\/p>\n

While in the field of switching amps, let’s include the NuPrime ST-10<\/a>. I’ll not beat around the bush: the little NuPrime has bigger bass and sounds more sonorous, bolder and more “live”-like. Note that I am not saying that it is more lifelike<\/em> but its delivery does come across more like that of a band playing live<\/em>. It is vigorous and plays with real gusto and I really like it for that. But the ST-10 also has its weaknesses, most notably its resolution and treble performance. While the Master 3 does not have the ST-10’s drive and slam, especially in the bass, it does outperform the latter in terms of neutrality, even-handedness, overall refinement and treble performance in particular. The Master 3 also has a lot more power but with my speakers, it can’t really play out that trick. Nevertheless, even with relatively efficient speakers such as the Wilson WATT\/Puppy 8 and the Kroma Audio Carmen, it is impossible to not have huge respect for what the Master 3 achieves, especially if I reveal its price in a bit.<\/p>\n

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Audio GD R8 R2R Ladder DAC<\/h3>\n

The R8 DAC has a similar appearance as the Master 1 preamp but because it is part of a different range, it uses panels that are shaped and constructed slightly differently. Nevertheless, it has the same purposeful looks and only a minimum of buttons on the front panel to make for a clean aesthetic. There is no remote control but the DAC offers a lot of options and this can appear daunting at first, especially when you’re not yet used to the somewhat strange logic that is used to change the settings using the aforementioned buttons. Indeed, I feel that its operation would have been more straightforward if they had opted to add two dedicated buttons for value changes but once you get the hang of its logic, you’ll be fine.<\/p>\n

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The R8 is a balanced discrete R-2R digital-analog converter equipped with advanced high-speed ladder correction including optimized FPGA FIFO buffering and re-clocking. Two high-performance TCXOs (Temperature-compensated crystal oscillators) are used to process the 44,1kHz and 48kHz sampling ranges. After D\/A conversion by the R2R modules, the analog signal is output via fully discrete, DC-coupled, matched-transistor output stages. Built-in 2X, 4X and 8X oversampling and digital filters as well as 4 different true NOS modes using 6dB analog filtering which makes for one highly configurable DAC.<\/p>\n

A true discrete Resistor Ladder DAC means that rather than a standard chip, it uses a range of resistors that are basically switched according to the number of bits used at any time in the audio stream. Naturally, these resistors need to be of very high accuracy but as the manufacturer points out, low tolerance in itself is not enough. The following calculation is used to point that out.<\/p>\n

At 16 bit, a tolerance of 1\/66536, 0.1% (1\/1000) is not enough to achieve decent performance. Even when using resistors with 0.01% (1\/10000) tolerance, which is the lowest tolerance available today, the desired performance cannot be obtained and this is just 16 bit. To process 24-bit resolution it would require resistors with a tolerance of 0.00001% which is purely theoretical. Even if this tolerance would exist, the switch logic chips will already have too much internal impedance and will shake-up such design. So, the tolerance of the resistor will never solve the Imperfections of a ladder. The solution lies in the combination of ultra-low tolerance resistors controlled by a correction technology using very high speed with parallel FPGA processing.<\/em><\/p>\n

As the manufacturer points out, many competing R2R products, especially affordable ones, use only the basic conversion and not the correction technology and therefore, they do not achieve the same level of accuracy. Every audio component is only as good as its power supply, so just like with the Master 1 preamp, the R8 DAC has a heavy emphasis on its power supply, using 3 R-core transformers and 21 low-noise regulation stages. There is a lot more info about DAC technology on the Magna Hifi website, including the pros and cons of R2R versus Delta\/Sigma so if you are interested, be sure to check that out.<\/p>\n

Although the R8\u2019s main selling point is clearly its R2R conversion of PCM signals, the DAC also supports high-resolution formats including native DSD64 – DSD512 as well as DxD. Unlike some other DACs, the R8 does not convert DSD to PCM but rather processes this via a separate converter. Personally, I only use PCM source material and don’t care much about DSD but I certainly appreciate the separate-path philosophy. A derivative of the more expensive R7, the R8 is said to preserve the same musicality with only minor changes to some parts of the circuitry. For instance, the output stages of the R7 are all independently buffered while the R8 uses a single buffer for all its outputs. That in itself is no issue at all and may even result in better sound. The downside of this is that you can\u2019t use its cinch and XLR outputs at the same time. You can, however, use ACSS and any of the two other outputs simultaneously. The R8 has plenty of inputs for every conceivable source: AES\/EBU, cinch, TOSLink, I2S on HDMI, and USB. The latter uses the Amanero USB class 2, 32bit chipset, rather than the often-used Xmos solution. As with the Master 1 preamp, outputs are provided as cinch, XLR, and balanced ACSS.<\/p>\n

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Sound<\/h3>\n

A very important aspect of an audio component’s delivery for me is tonality, or rather, that they sound natural. With the classic Sony ES components and later also with certain Chinese components, I found that the sound was somewhat synthetic, in other words, it was acoustically not convincing for me. This is not something that can be tagged onto entire countries such as China and Japan, though,\u00a0as clearly proven otherwise by the very natural sounding Accuphase and various other Chinese products that I reviewed. Rather, I think it is related to design choices and the selection of internal components, as well as the way that I interpret reproduced music with my systems. In any event, the Audio GD components have a wholly natural presentation: there is no artifice here!<\/p>\n

The obvious comparative partner for the R8 in my arsenal is the Aqua Formula xHD DAC because both DACs employ discrete R2R resistor conversion. At over 13K euro, however, this is, again, not a fair comparison. Using the Final Touch Audio Callisto USB cable and AudioQuest Water cinch interlinks for both DACs, there was absolutely not the huge difference that I was expecting. The Aqua is a little smoother, more refined, especially in the treble, and it also has an even more linear presentation, flatter in perceived frequency curve so to say. So, the Audio GD is less well-differentiated, a little bit rougher and not as ruler-flat.\u00a0But that really is all there is to it. Otherwise, I really cannot say that there are any meaningful sonic differences between these two DACs. And that really is a remarkable achievement.<\/p>\n

For the most refined sound, I found that the Final Touch Audio Ganymede worked best and the Cardas Clear was also a good combination. The Vermouth Reference XLR yielded a more sonorous and more powerful and very precise sound but in this case, I preferred the gentler and airier treble performance of the other two cables.<\/p>\n

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The best setting for my ears: sync and PLL set to zero and no oversampling.<\/em><\/p>\n

DAC filter settings<\/h3>\n

The number of options that the DAC offers can seem overwhelming at first but when you get down to it really is quite simple. Basically, you have the option to listen with or without oversampling, the latter commonly referred to as NOS. Where it gets a little bit more complicated is that in each of these settings you have further options to refine the sound. In the\u00a0oversampling mode, you can select 1x, 2x, 4x, or 8x oversampling. Between these 4 options, I don’t hear a whole lot of difference but your mileage may vary. In the NOS mode, you can select mode 1 (simplest data process), mode 2 (data FIFO process), or mode 3 (fastest data process). Between these modes, I hear clear differences, mode 3 sounding smoother and more “filtered” and mode 1 sounding most articulate and direct. Mode 2 I don’t really know what to make of but it also has a certain “filtered” just like mode 3. Of all the options, I most prefer NOS and mode 1 but I also like 1x oversampling for its slightly smoother presentation than either of the NOS modes, which may work very well in systems that inherently are a little forward or possess a little edginess. With the Kroma’s and the Naiu Ella amp, I have a clear preference for NOS mode 1. In this mode, it most resembles the Aqua Formula xHD DAC and it was in that mode that I made the comparisons.<\/p>\n

The first discrete R2R DAC that really blew me away was the 1600 euro EC Designs Mosaic T-DAC<\/a>. This DAC managed to outperform much more expensive DACs, primarily in terms of refinement and purity, but ultimately fell through for me because its bass lacked attack and <\/span>drive, due to its very purist design that does not use any output stage. The next discrete R2R DAC that had me smitten was the Aqua Formula xHD and it did all that the Mosaic did along with tuneful and powerful bass. The Aqua has a hefty 13.670 euro price tag but to this day it remains my\u00a0reference in its price class. Where does this leave the Audio GD R8? Pretty darn close to the Aqua, actually! Apart from the Aqua, it is with ease the best discrete R2R DAC that I have heard. And even when taking “regular”, non-discrete R2R DACs into account, all the ones I really liked invariably carried<\/span>\u00a05000+ euro price tags. I’ll refrain from mentioning the Audio GD prices just a little longer but suffice to say that the R8 is A LOT less than that.<\/span><\/p>\n

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Although the Kroma Audio Carmens managed to stay out of sight in most of the pictures, the majority of the review has actually been conducted with these speakers, with the Wilsons moved to the side of the room.<\/em><\/p>\n

ACSS Sound<\/h3>\n

I already explained the principle behind ACSS in part 1 of this review but now I’d like to dive more into the format’s aural aspects, relative to the cinch and XLR connections. Along with the Audio GD components, Jos delivered Audio GD ACSS cables as well as Magna Hifi M-Way ACSS cables which they manufacture themselves.<\/p>\n

Starting with the Audio GD ACSS cables used between Master 1 preamp and R8 DAC, I was quite astounded by their performance. Although less colorful or less timbrally rich than some of my other cables, even these very affordable cables managed to outperform any of the other cables by sounding a lot less restrained dynamically and by having much freer soundstaging that was also more enveloping. The ACSS cables somehow allowed for better 3D imaging and a larger swing in the depth plane, images being more behind the speakers as well as more in front of them.<\/p>\n

\"\"<\/p>\n

Audio GD ACSS cables in black and Magna Hifi M-Way ACSS cables in red and blue.<\/em><\/p>\n

Further upping the game with the Magna Hifi M-Way ACSS cables, the aforementioned advantages of the Audio GD ACSS cables remained but enhanced with a smoother, more natural delivery that was more voluptuous and more richly textured, yet, while retaining the transparency and without sounding too warm. These cables make the Audio GD components sound\u00a0richer and more relaxed yet still crystal-clear and with infectiously spot-on pacing. What convinced me most of all about the M-Way ACSS cables was the combination of factors such as even-handedness, warmth, and transparency and a seemingly ruler-flat frequency curve as well as a dynamically more outgoing and more free-flowing delivery.<\/p>\n

In the section about the R8 DAC, I mentioned how it compares to the Aqua Formula xHD DAC, both using cinch cables. Switch to M-Way ACSS connections between R8 and Master 1, though, and the difference in quality between the two DACs becomes a really close call. With these cables, on the one hand, the Audio GD now had the upper hand in terms of depth of soundstaging and the feeling of being enveloped by a more free-flowing sound, on the other hand, the Aqua (with no ACSS connections) still sounded a little bit more refined and transparent and refined.<\/p>\n

The M-Way ACSS cables outperform all the other cables that I tried, including Cardas Clear and Hexlink Golden 5C, Vermouth Reference, Final Touch Audio Ganymede, and AudioQuest Water.\u00a0These cables do all offer a change in perspective and of course one could opt to tweak the sound that way. For instance, the Hexlink sounds fuller and more voluptuous, the Vermouth sounds more solid and precise and the Final Touch Audio sounds more relaxed and more seductively refined. However, their relative merits aside, all these cables’ presentation with the Audio GD components is somehow more business-like, more matter-of-fact than with the ACSS cables. I can only conclude that\u00a0Current Conveyor Technology, in this case in the shape of ACSS, absolutely has a considerable added value over XLR and cinch.<\/p>\n

USB Blaster<\/h3>\n

\"\"<\/p>\n

Audio GD has a history of being highly tweakable. Older generations of their equipment could be altered in many ways by replacing jumpers inside but current-generation equipment can be updated by using a USB Blaster as pictured above. This way, one can upload firmware updates that allow new features such as a TDA1541 emulation with two passband options and other NOS\/OS options. Currently, 4 firmware issues are available for the R8, free of charge. If required, Magna Hifi will assist with the process.<\/p>\n

Retail Prices<\/h3>\n

If you haven’t looked them up already, finally, here are the retail prices in the Netherlands, including 21% sales tax. Now tell me, honestly: did you expect them to be this low? I certainly did not.<\/p>\n

Audio GD R8 DAC: 1649 euro
\nAudio GD Master 1 preamp: 1399 euro
\nAudio GD Master 3 power amp: 2199 euro
\nAudio GD ACSS cables (mini XLR\/mini XLR): 33 euro for a 1-meter pair
\nAudio GD ACSS cables (mini XLR\/4P XLR): 55 euro for a 1-meter pair
\nMagna Hifi M-Way ACSS NTRL cables (mini\/4P XLR): 375 euro for a 1-meter pair<\/h4>\n

Conclusion<\/h2>\n

I’ll be honest: I think that the R8 DAC is the star of the show, sounding very nearly as good as the Aqua Formula xHD DAC which given its\u00a0low price is an amazing achievement. But don’t assume that the Master 1 preamp and Master 3 power amp are mere bystanders. This pre-power pair also offers extremely good value for money, delivering a combination of transparency, neutrality, and even-handedness that is normally impossible in this price class. I think you can easily spend double the amount and not get better sound.\u00a0But the most amazing aspect of all is perhaps the further increase in performance when all the components are wired using the proprietary ACSS connections, giving the system such a leap in performance that it becomes impossible to fault, even in the company of esoteric hardware. Oh, and should you still be worried about the build quality of these products then the 10-year (!) warranty should instill confidence.<\/p>\n

 <\/p>\n

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\n(Master 1)<\/p>\n

 <\/p>\n

\"\"
\n(R8)<\/p>\n

Associated Equipment<\/a><\/p>\n

Read Also<\/h3>\n

Audio GD Master 2H Mono Power Amplifiers and a revisit of the Master 1 preamp<\/a><\/p>\n

External Links<\/h3>\n

Audio-GD Reseller (including service and repair) for Europe: Magna Hifi<\/a>
\nManufacturer: Audio GD<\/a><\/p>\n

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