Today I will tell you about an incredibly interesting device. It just so happened that the built-in sound cards of modern laptops obviously cannot please the owners with high-quality sound. External DACs, usually connected via USB and acting as a sound card, come to the rescue. Today I will tell you about one of the most compact solutions of this kind. Concurrently, it is also the most inexpensive, but it sounds very good. It's about .
The development of modern microelectronics has led to the emergence of truly remarkable microcircuits. A striking example is the Saber 9023 DAC from ESS Technologies. Its main advantage is that it requires minimal “strapping” and at the same time provides enough power at the output to listen to headphones without an amplifier. Of course, manufacturers of solutions for music lovers and audiophiles could not ignore it and created quite a few solutions based on it, I even described a couple: ODAC and iFi iDAC. Due to the small size of this microcircuit, several miniature DACs were also created that do not exceed the size of a regular USB flash drive. One of the most famous - unnecessarily expensive Dragnofly from Audioquest.
Appearing relatively recently, the HiFiMeDIY DAC has won quite a few fans, as evidenced by the high places in the Head-Fi ratings (at the time of this writing - # 4 in the DAC rating!). Of course, this solution is not for “audiophiles”: they need a “firm with a name”, “exclusive technologies for making a 5-layer board” (even if they are not in the device) and other delights. But U2 is perfect for those who want to get a better sound than the built-in sound card of his computer provides, without spending a lot of money (price of $ 57 DAC) and space.
What is a DAC and why is it needed? I already talked about this in my review of the HiEnd solution of Yulong DA8, but just in case, I repeat. The DAC connects to your computer and works as an external sound card (more precisely, its half is playback-oriented, as DACs usually do not contain audio inputs). The computer transmits sound to the external DAC in digital form, and the latter translates it into analog form. Since the circuit design of even a simple DAC is better in 99.999% of cases than the built-in sound card of a laptop or computer, the sound of a separate device is noticeably better.
Separately, I note that HiFiMeDIY in the range has several modifications of DACs on this chip and in this form factor: normal, for Android, and asynchronous. In the case of the Andorid DAC, everything is more or less clear: it connects via USB OTG to devices on this operating system that supports the USB Audio protocol and allows you to listen to music with a quality that exceeds the on-board solution of the smartphone. There is also a cheaper and simpler solution, as well as a DAC with a built-in headphone amplifier.
So what is the difference between an ordinary DAC and an asynchronous one?
A “normal” converter acts as a receiver of a digital signal: a computer sends information bits at a given speed, and “is not interested” in how the DAC received them. In this case, the DAC requires an incredibly precise frequency matching with the computer, which is not always achievable in practice. The mismatch of reception and transmission in this case leads to the appearance of "jitter", which degrades the sound quality. An asynchronous DAC works differently: it sends to the computer (or another source) requests for the next piece of data, and processes them. This mode allows you to avoid any form of mismatch. Therefore, a small overpayment for the asynchronous version of the DAC from HiFiMeDIY is quite justified.
Specifications
Characteristics of U2 are not published much. Here is what I managed to collect.
- Supported modes: 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz and 96 kHz, 16 and 24 bits
- Input: USB
- Outputs: 3.5 mm audio combined with optical
- Output level: 2.1 Vrms with a load of 4.7 KΩ, 1 Vrms with a load of 30 Ω
- Dynamic range: 112 dB
Design
The look of the U2 is incredibly minimalistic. It fully justifies its name in the sense that the developers have managed small-scale production. U2 does not have a box, it comes in the usual package of "pimply" polyethylene. The case is a small rectangular parallelepiped, on one end of which there is a short USB cable for connecting to a computer, on the other - a 3.5 mm output for an audio signal. The same connector serves as an optical output jack, which allows you to use U2 as a converter from USB to optics. In the corner of the device is located LED display work.
In general, the design is simple, without frills, but given the marginal price and compact size, it is silly to find fault with it. Moreover, it is worth noting that the internal performance of the DAC is at a sufficiently high level, high-quality soldering, they did not save on details (within the device’s budget, of course).
Sound
The following equipment was used for listening:
- Apple MacBook Pro 15 ″ early 2011
- USB iFi iUSB Power isolator
- Decibel as a player
- Records in lossless formats
- Audio-GD NFB-6 as an amplifier
- Headphones: Fischer Audio TBA-04, VSonic GR01
ESS Saber 9023 - the chip is almost self-sufficient. It does not require complex tying (although it does not exclude it if developers want it), therefore, in creating DACs on it, the main thing is not to spoil it. U2 developers have succeeded in this in full. In the role of the USB interface, they used the SA9023 chip from SAVITECH (despite the coincidence of the indices, this chip has nothing to do with the DAC chip itself). The generator uses a 27 MHz cavity with a PLL1705 microcircuit. The design of the DAC uses a circuit without coupling capacitors at the output, which also has a beneficial effect on the sound.
Windows users can use the ASIO drivers developed by SAVITECH.
The funny thing about this device is that it plays no worse than many more expensive solutions, and some even bypasses it. First of all, this is the merit of good DACs and a controller, and secondly, in a competent circuit solution.
Out of the box, the sound of the U2 is detailed, rather cold, but without the annoying RF surplus. There is a lot of air and lightness in the sound, although the bass also plays out well. Sibilance is weak, background noise depends on the quality of your USB-out (see below about the filter). Volume reserve is sufficient for most headphones that are not tight. Well, this DAC is combined with different amplifiers, due to its “transparency”, it practically does not introduce distortions into the sound image.
Modification
To unlock the full potential of U2, I sent it for revision to a familiar master. In the course of finalizing the DAC has undergone many changes:
- tantalum capacitors removed from the analog path and replaced by electrolytic larger capacitance
- recalculated filter and its components are replaced with better ones, and the amplitude of the output signal is slightly reduced to achieve greater detail
- implemented a separate power supply DAC chip
- part of capacitors shunted by ceramics
Since this modification could not fit in the original case, holes for the capacitors were cut in the cover and the entire DAC was shrinked. The view turned out to be a bit handicraft, but the increase in sound quality is more than justified.
After the modification, the player’s sound becomes less pronounced-cold, the low-frequency drive is added, which makes the sound of the DAC more musical. The sound becomes “multidimensional”, the imaginary scene becomes more voluminous, the separation of instruments improves.
USB filter
Since U2 is powered by USB, and the small size does not allow for a serious power filter, the sound of the DAC depends on the quality of the USB bus implementation in your computer. To solve this problem, HiFiMeDIY offer a simple but effective isolator. It is made in the same form factor as U2, but instead of an audio jack, it has a USB connector. Turning it on before the DAC (it doesn't have to be U2), you can significantly improve the quality of USB power and improve the sound.
findings
Very inexpensive device with great potential. Do not be embarrassed by a very simple appearance, for its modest price this small DAC can please the owner with a very good sound.
The article is based on materials .
Comments
Post a Comment