SAGRA dac is an external desktop decoder that uses an R-2R discrete resistor array to implement the DAC function. It sells for more than 20,000 yuan and is positioned as a high-end product. The product was released around 2019 and is a representative product after the establishment of the new brand.
SAGRA R-2R external decoder
Due to the recent testing of many decoders, headphone amplifiers and other products, the evaluation must include comparison and matching content, although the comparison with the decoder "Quan 3" with the same R-2R structure More than 90% has been completed. This article can even be written about two comparisons and several headphone combinations at once, but it seems that there is too much content. Therefore, this article will include the subjective listening experience of the SAGRA DAC paired with the speaker system, as well as a simple comparison of "Quan 3", a small comparison of USB and S/Pdif digital inputs, and some objective functions and tests of the decoder. In the future, more detailed combinations will be left in the subsequent headphone and amp evaluation, and more comparisons will be left in the "Quan 3" decoder evaluation. Let’s get down to business.
Appearance, function and internal main configuration
SAGRA R-2R External decoder
Appearance: SAGRA DAC is a decoder priced at more than 20,000 yuan. The configuration and craftsmanship of the chassis are not exquisite, and the materials used are relatively average, which is considered quite good. Low profile. Different consumers have different understandings of this style. Some people think that money should be spent on cutting-edge sound quality first, while others think that the appearance of such a high-positioning product is also important.
SAGRA R-2R External decoder
SAGRA There is a small screen in front of the DAC. It is mainly used to display the working sampling rate and status during operation. In terms of control, it is mainly used to switch input sources through a small button on the front panel.
interface: comes to the back of the decoder and sees the interface distribution. Since the size of the machine is not very large, the interface on the back is almost completely occupied, and the distinction between the input and output areas is not very clear. The output section includes two XRL balanced outputs and a pair of RCA outputs on the left side of the picture. The balanced output voltage is ±2Vrms, but the single-ended output of RCA is only 1.4Vrms for some reason.
SAGRA R-2R external decoder - on the back
is next to the output part, which is the coaxial S/Pdif input and BNC output of RCA1, and there is an S/Pdif optical input above. Another area is the USB-B input, HDMI IIS input [there are two sets of definitions], RCA2 S/Pdif input and AES digital input. According to the official introduction, the digital input quality of RCA2 is higher, and the compatibility of RCA1 is better.
SAGRA R-2R External decoder - back - various interfaces
SAGRA R-2R External decoder - back - digital input interface
Function: SAGRA DAC supports 384kHz 32bit PCM input in terms of USB interface, but under macOS , identified as supporting up to 768kHz [this refers to the USB Audio part, not the DAC]. It can support decoding up to DSD512 [under Windows], and the highest decoding under macOS is DSD256. This set of USB and digital input solutions comes from amanero's combo384, which is also a relatively famous USB Audio solution for many years.
As for the SAGRA DAC's own decoding capabilities, it can achieve PCM decoding up to 24bit/384kHz and DSD256 under USB and IIS input, and supports up to 24bit/192kHz PCM decoding under S/Pdif input. The internal main structure of
: There seems to be a controversial point in this decoder of , that is, although the internal sub-cards look neat and beautiful, everyone quickly found its origin and thought it looked like a piece of work. The official does not shy away from this. Its R-2R daughter card or main card comes from the solution of Sokeris Company, but it is indeed different from several models on public sale. The manufacturer officially stated that it comes from a customized version. The solution provided by sokeris seems to be relatively complete, not only the R-2R part, but also the subsequent analog output.
SAGRA R-2R External decoder - disassembly - DAC and digital part motherboard
As shown in the figure, Sokeris's R-2R solution is also based on the FPGA programmable design to control a resistor array to realize the function of the DAC. The structure of R-2R, simply put, is the classic digital-to-analog conversion medium-weighted resistor circuit we have learned, cleverly simplified to only need two resistance values: one R and one 2R [2 times R resistance] To achieve multi-bit D/A.Referring to Sokeris's dac1421, it can achieve a decoding sampling accuracy of 27 bits. The specific standard in SAGRA is unknown [all levels of Sokeris solutions can achieve 27 bits]. The I/V part after the DAC is completed by the discrete component transistor .
SAGRA R-2R External decoder - disassembly - USB digital daughter card
SAGRA R-2R External decoder - disassembly - R-2R motherboard - 74LVC595A shift register chip and resistor, etc. constitute
and the digital input and USB input parts , as mentioned earlier, comes from amanero's combo384, this is the public version. There is no conflict between having DIY assembled components and making the assembled finished product your own brand and selling it successfully. There are countless cases over the decades, from computers to stereos, and there’s nothing to argue with. The manufacturer has not deliberately concealed this, and smart consumers also have the right to pursue higher cost performance, and it is normal to even have the desire to install one themselves.
Objective Test and Subjective Listening
Objective Test
In the objective test, we conducted an objective signal test and analysis on the XLR balanced output of the SAGRA DAC. The decoder itself is not designed with a volume adjustment function, and the output voltage is ±2Vrms.
SAGRA R-2R External decoder - frequency response curve
SAGRA R-2R External decoder - noise distribution
SAGRA R-2R External decoder - dynamic range
SAGRA R-2R External decoder - total harmonic distortion
SAGRA R- 2R External decoder - intermodulation distortion
SAGRA R-2R External decoder - separation curve
| test item | 44 | 96 |
| noise level, dB (A): | -94.9 | -115.6 |
| dynamic range, dB (A): | 94.9 | 115.3 |
| total harmonic distortion, %: | 0.00733 | 0.00749 |
| intermodulation distortion, %: | 0.00951 | 0.00831 |
| stereo separation, dB: | -94.0 | -101.9 |
SAGRA R-2R External decoder-frequency [email protected]
SAGRA R-2R External [email protected]
SAGRA R-2R External decoder - separation frequency analysis @44.1kHz
SAGRA R-2R External decoder - frequency scan @96kHz
SAGRA R-2R External decoder - frequency scan @DSD 20Hz-48kHz
Judging from the RMAA test results, although the signal-to-noise ratio and dynamic range performed well, the distortion was indeed not low. Is this caused by the accuracy of R-2R, or is it caused by the analog circuit of discrete components not being as good as the op amp? ? Or deliberately pursuing this taste? Perhaps all of these factors exist. In the objective testing section, there doesn’t seem to be much to explain.
Subjective listening experience
In the subjective listening test, this article will not talk about the performance when paired with amps and headphones. Recently, it will be related to the performance of SAGRA DAC in the amp testing. Since everyone is very enthusiastic about the comparison between the R2R2000 Red Prince player using PCM1702, we will also make a simple reference. It is not because the two are similar, but because the R2R2000 player does a good job in expressing the sound styles of PCM1702 and PCM1704. sex. In addition, we will also briefly compare "Quan 3" and talk about "Quan 1" based on our impressions. The test speakers selected Airpulse A100 and Xindak A600 amplifier + Gentleman D3004 + Weifa ne180w-08 bookshelf box as a reference.
SAGRA R-2R external decoder
Overall impression: The overall sound style of SAGRA DAC is a stable and loose style among R-2R decoders, which can be regarded as a relatively typical sound style. The loose and stable listening feeling is due to the R-2R itself. , there is also the influence of discrete component analog circuits. Let’s take a look at the R2R2000 Red Prince first. The SAGRA DAC is better than the R2R2000 in terms of mid-frequency dynamics and thickness. The low-frequency volume is slightly smaller than the R2R2000, but it still feels rich, especially in the deeper parts. The sense of volume is not small, and it has the characteristics of R-2R transient stability, which sounds quite enjoyable. Audiences who like to watch the fun, SAGRA DAC is not even inferior to a player.Its overall dynamics, higher mid-frequency, high-frequency quality, looser overall, and stable listening feel make it belong to the level of advanced decoder products, and this style can compete with the tens of thousands of yuan-level ESS, AKM, and CirruLogic families. It is definitely superior among similar products.
treble performance: The high frequency of SAGRA DAC is slightly more dense than R-2R. It should be related to the design of the analog part. There is a slight pulling feeling when paired with silk film treble, but it is paired with the more powerful aluminum strip type. The treble is more vivid. But overall, the quality of this high frequency is good. Compared with various products of Delta-Sigma, the treble has very few traces of modification, and the transient speed is just right, neither too fast nor too slow. And under this balanced style, There is no lack of sound resolution. Even if the treble of some music recordings is more aggressive, or some exciting percussion high frequencies are encountered, the control under the SAGRA DAC is very good, and the sound level is clean, stable, and calm. This can be regarded as the characteristics and characteristics that R-2R should have at a normal level. If this is not possible, I don’t know why I would play R-2R.
In terms of the performance of treble string instruments, the SAGRA DAC paired with the above two sets of speakers both performed mellow and gentle. It may be because the A600 amplifier has a little bit of modification in the treble, but I feel that this combination is not as smooth as the A100. clean. But it is also because the A600 amplifier is powerful enough and the silk dome tweeter is powerful enough that its high-frequency dynamics can be better displayed. In terms of extreme high-frequency extension, it is not the advantage of R-2R. People who like to listen to ultra-fine details are not its specialty, but it is not necessarily what it will be like with headphones. The treble part of
plays an important role in the sound field performance of the entire audio system. Overall, SAGRA DAC shows a good enough sound field under two audio systems, and on the other hand, it has stable transients and very good control. It makes it It seems that I have become less picky about the sound field of amplifiers and speakers.
mid-range performance: The vocal performance of SAGRA DAC is full and full of tension. The distortion in its objective indicators can be clearly reflected in the vocal performance. Compared with the cleaner and more thorough "Quan 3", we will feel that SAGRA DAC The vocals have a grainy feel with some larger particles, which subjectively can be understood as a modified listening experience. This style makes the outline of the vocal sound more clearly outlined. Coupled with good dynamics and slightly forward imaging, the vocal performance is excellent, especially when paired with the A100. Whether it is a mature jazz female voice, a popular female voice, a male voice that needs fullness and thickness, or a younger female voice that needs sweetness and polish in the treble part, SAGRA DAC performs well. Relatively speaking, it may not be too "female poisonous", or it may be quite mild.
is also powerful enough when it comes to mid-range classical music , large dynamic symphonies, etc. However, the large graininess at this time cannot be fully understood as a modified positive listening experience. Relatively speaking, in some cases The graininess in the mid-range and mid-bass will make the sound slightly thicker and not smooth enough. But, is it possible that your sound system just smells like this? This is really not necessarily the case. Also consider personal preferences and tastes. In this part of the performance, the SAGRA DAC is not very fine in terms of details, and even the mid-low frequency part is relatively rough. But we believe that this kind of roughness in details and resolution should not be completely related to good dynamics. If it can be more delicate while maintaining sufficient dynamics and the same thickness, it will be more advanced. Let me mention "Quan 3" again. In this part, "Quan 3" is much more delicate and clean, but the taste is also slightly lighter.
bass performance: SAGRA DAC is relatively smooth and natural in the mid-low frequency connection part, and the transient speed is slightly slower among R-2R. The thickness of the mid-low frequency is not as thick as the HiFiMAN R2R2000 Red Prince. Of course, it feels looser and the sound is more detailed. However, in the deeper part of the dive, SAGRA DAC seems to suddenly gain strength. Paired with our 6.5-inch vifa unit, the dive is amazing. big drum in classical symphony, cannon or various special effects in movie music, the performance is as good as The depth of the dive is surprising and shocking many times.This also tells us that you may not need a speaker with a 4-inch or 5-inch mid-woofer to match such a decoder. The mid-low frequency of
SAGRA DAC has good support for the mid-frequency, while the performance of cello, , etc. is more loose and grainy. The control is good, but not clean. When paired with a small-sized metal cone like the A100, the particularly fast low frequencies in music do not perform well. It can be considered that the style of the sound system is not suitable, but it is indeed due to the performance of the transient control of the sound source part. In classical music, for slower low frequencies, or choosing more powerful subwoofers and amplifiers, SAGRA DAC, which is a slow and deep style, has a listening experience that is at least as good as jazz and classical music slow low frequencies. Performed well below. So relatively speaking, it's a bit like a very traditional R-2R transient, giving up a little transient control in order to dive.
amanero combo384: This is a hybrid module of USB and other digital inputs. We used the coaxial input of the ancient Lezhibang 02US MarkII to test it against its own USB. Overall, amanero's USB Audio part performs well. Although it is quite famous, this is the first time we have used it. The style definitely does not have the hard and dull trend that is common in XMOS. 02US MarkII's S/Pdif is famous for being very loose. , but in comparison, it is indeed looser than the original USB, but the changes are smaller. However, it is also possible that this is a whole digital input unit, and its internal PLL and so on have been processed, so there is not much difference between different input sources.
DSD, upscaling, etc.: In recent tests of , we found that today’s players are again keen on upscaling and global conversion to DSD? As can be seen from the above description of the sound style of SAGRA DAC, in addition to being stable and loose, it may be a bit heavy on the mid-low frequency range, so if you want to adjust the taste by upscaling, it is really advisable. It has been seen in the manual of CHORD, the "big upconverter", that by using a smaller level of upconversion, you can get a warmer sound. Therefore, upscaling can indeed make the sound more compact and smooth, and there will also be small changes in the density and texture of high frequencies. Whether you use SoX or iZotepe, there are specific parameter settings, and you can also weigh and adjust between looseness, refinement, and transient speed. It is worth playing. For the richer, less refined style of SAGRA DAC, upscaling is more appropriate. For Quan 3, which is already very refined, there is actually no need to play with upscaling. Regarding
DSD, the R-2R used for PCM cannot theoretically decode DSD. Currently, according to other third-party reviews, it seems that it is played after conversion from DSD to PCM [note, not DoP], so I am not sure.
Summary
SAGRA DAC's overall performance is satisfactory. Like most consumers, we certainly feel that the price of more than 25,000 yuan is obviously still very high. However, in the evaluation of teacher Liu Hansheng, he said that this is the lowest price and best performance that he has ever used. Good decoder. Looking at the HiFi decoder products released in the past 2-3 years, they are not only increasing their prices silently, but also using the cost to build digital broadcast systems. For consumers who prefer to purchase the ultimate sound quality, your purchase cost It is indeed much higher than a few years ago.
As a product priced at more than 10,000 yuan, the sound performance of SAGRA DAC is worthy of its positioning. Considering only the sound performance, this R-2R solution is definitely better than mainstream IC DACs such as AKM, ESS, CirrusLogic, which are also rated at 10,000 yuan. similar products. It has the traditional taste of the PCM1704 era in my impression [not much PCM1704], the sound is warmer, and even the low frequency is slightly rich. As a desktop decoder, the higher quality linear power supply and discrete component analog circuits combined with R-2R bring a loose and stable listening experience, which is obviously better than portable devices. At the same time, the mid-frequency part, especially the vocal performance, is very good. The larger graininess and fuller sound may be the result of intentional tuning of the overall tuning. The dynamic performance and low-frequency dive depth are also impressive. If you still want to pursue more extreme details and a cleaner level, that will be discussed in the next "Quan 3" evaluation.
