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iBasso DC01 Hi-Res Balanced DAC cable adapter

Rating:
5/5,
  1. twister6
    Audiophile dongle.
    Written by twister6
    Published Jul 14, 2019
    5.0/5,
    Pros - AK4493EQ DAC, 2.5mm fully balanced output, smartphone and PC compatibility, wide soundstage, expanded dynamics, custom app to control the volume, budget price.
    Cons - some “waterfall” hissing with sensitive IEMs.


    The product was provided to me free of charge for the review purpose in exchange for my honest opinion. This review was originally published on my blog, and now I would like to share it with my readers on Head-fi.

    Manufacturer website: iBasso. Available for sale directly from iBasso or other retailers like Penon Audio.

    *** iBasso DC01 was tested with my [US] Verizon Galaxy S9 (Snapdragon processor) without any problem.


    Intro.

    As I started working on this write up, I tried to remember the last time I reviewed a compact USB DAC dongle. It has been a while, and there is a good reason for that. The sound quality of Android phones wasn’t that great 4+ years ago. Some manufacturers quickly recognized the demand, turning a smartphone into a touch screen digital transport to drive portable USB OTG DACs, and many audiophiles found it useful since touchscreen streaming DAPs were rare at that time. But as the sound quality of smartphones went up and Android support of high res formats improved, the interest in these dongles started to fade away, especially with more dedicated Android DAPs hitting the market.

    So, imagine my surprise when out of the blue while waiting to receive their latest AMP9 w/Korg NuTube, I get a bonus DC01 dongle from iBasso. It was a surprise on many levels, maybe because I missed their upcoming products announcement or perhaps because I couldn’t understand why would a company with such a variety of Android and non-Android DAPs would release a USB DAC dongle? It wasn’t a question of a new product entering the saturated market (cause it’s not), but rather a question of is there even a demand for it? I know iBasso doesn’t put out random releases, so there had to be something special about this new DC01 USB DAC cable adapter. Here is what I found after spending the last few weeks testing it.

    Unboxing and Accessories.

    The unit arrived in a very compact cardboard box with a realistic 3D image of the device popping out from the cover sleeve. Despite small size of the box, there was plenty of info on the front and the back to highlight its functionality, design, and spec. The key features I noticed right away were a balanced output and AK4493EQ DAC which is quite unique for $49 device.

    ibasso_dc01-01.jpg ibasso_dc01-02.jpg ibasso_dc01-03.jpg ibasso_dc01-04.jpg

    With a sleeve off, you’ll see a foam cutout with DC01 securely wedged inside and a flap covering the cable/connector portion of the device. As part of the included accessories, there was USB-C to USB-A short adapter and a detailed manual. It’s always nice to see manufacturers paying close attention to packaging details, regardless of the product’s pricing.

    ibasso_dc01-07.jpg ibasso_dc01-08.jpg

    Design and Functionality.

    DC01 main aluminum housing, kind of bulbous in shape, is about 38mm long, very lightweight, and hosts the 2.5mm balanced headphone jack, AK4493EQ DAC, dual ultra-low noise LDO voltage regulators, a blue led (to indicate the presence of power), and the rest of the circuit. A matching aluminum housing USB-C connector plug is attached with a short 8-wire braided cable, the same premium hybrid cable (4 pure copper and 4 SPC conductors) iBasso uses with some of their IEMs.

    This interconnect cable will carry only a digital signal from USB-C connector to the DAC, but since we have multiple conductors, it allows to separate power, ground, and data signals, keeping them apart and isolated. Overall, this pigtail design looks very nice, especially when used with matching iBasso IEM cables. The total length of this pigtail adapter is about 120mm, and the total weight is about 10g.

    ibasso_dc01-05.jpg ibasso_dc01-06.jpg ibasso_dc01-09.jpg ibasso_dc01-10.jpg

    Along with AK4493EQ, the spec mentions output voltage of 1.9V and output power of 113mW @ 32ohm load. Also, considering USB-C connection, it’s designed for use with Android phones/tablets, and with included USB-C to USB-A adaptor you can also connect it to your PC/laptop to use as an external USB DAC soundcard. With Win10 there is no need to install any additional drivers (confirmed on my Win10Pro laptop), but if you have an older version of Windows, iBasso has drivers for that.

    With a smartphone, assuming you have the latest one with usb-C plug, you need to connect DC01 directly and it should be recognized right away. I was using Neutron app for playback, and had no issues with my Verizon Galaxy S9. Since there is no built-in battery, DC01 will be draining extra from the phone, but it wasn’t too bad. I noticed on my Galaxy S9 while using Neutron with WiFi/BT on, the drain was about 5% per hour when playing FLACs. With DC01 attached, under the same test conditions it went up to 9%.

    ibasso_dc01-11.jpg

    Unfortunately, due to smartphone variations in hw and Android sw, there could be an issue related to inconsistency with max volume. To resolve this problem, iBasso released free UAC volume control app which could be downloaded from Google Play. It starts up every time DC01 is attached to the phone, allowing you to control the volume in 64 hw steps which helps to reduce the noise floor due to a finer volume adjustment within audio apps.

    ibasso_dc01-20.jpg

    Sound Analysis.

    I analyzed DC01 sound performance across pair ups with different smartphones, laptops, other DAPs, and with different headphones while playing a variety of my favorite test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ariana Grande “Break up with your girlfriend”, Ed Sheeran “Shape of you”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.

    The sound analysis was based on comparison between headphones beings connected directly to various source vs being connected to DC01 paired up with those sources, or just A/B comparison between other USB DACs and/or portable DAPs.

    In the following sections of my reviews I will go into more details for each comparison, but overall, I found DC01 to stand out with a very wide soundstage expansion (the first thing that captures your attention), a neutral natural tonality with a fuller body, great sound dynamics (vertical expansion, the sound never felt compressed), and a decent layering and separation of the sounds (keeping everything uncongested).

    I do have to admit there was some slight “waterfall” hissing with lower impedance sensitive IEMs where you can hear it either when idling or in quiet passages of the songs. But it wasn’t too distracting, and not noticeable with full size headphones, dynamic driver IEMs, or higher impedance IEMs.

    In a few more specific examples (S9 refers to my Samsung Galaxy S9 phone):

    S9 vs S9+DC01 w/iBasso IT04 – with DC01 soundstage is wider, the sound is more transparent, noticeably less coloring in comparison to warmer direct output of S9, improved layering and separation of sounds, and improved dynamics.

    ibasso_dc01-16.jpg

    S9 vs S9+DC01 w/iBasso SR1 – with DC01 I hear a wider soundstage, a better pair up synergy with a more natural tonality vs when connected directly to the phone the volume is still loud but the sound is brighter, rougher, and not as coherent as with DC01.

    ibasso_dc01-18.jpg

    S9 vs S9+DC01 w/Meze Empyrean - directly from a phone the soundstage is narrower, tonality is brighter, not as natural, and the overall tuning doesn’t sound as coherent. With DC01 the soundstage is wider, the sound is smoother, more natural, with more expanded dynamics, and improved layering and separation.

    ibasso_dc01-19.jpg

    With both of the full-size headphones above, you can drive them directly from my phone, but the tonality was off, being brighter, brittle, and not as coherent. With DC01, the soundstage expands wider, the tuning is more coherent, and the sound is smoother and more natural. I’m not saying DC01 will drive them to their full potential, you have to be more realistic since both cans would benefit from a more powerful source, but DC01 can definitely improve the sound of my smartphone even when driving more demanding full-size headphones.

    ThinkPad T480s laptop vs T480s+DC01 w/iBasso IT01s – connected directly, T480s has a more compressed sound with a narrower soundstage, while T480s+DC01 yield a much wider soundstage expansion and better sound dynamics (vertical expansion) with improved layering and separation.

    ibasso_dc01-12.jpg

    Comparison.

    Unfortunately, most of my usb-OTG DAC devices are from 4 years ago, and many are probably not as relevant. In this comparison I will go down a memory lane with two Cozoy devices. But before I do that, let me take a quick look at a comparison to Shanling M0 and VE Odyssey. I know M0 is just a portable micro-DAP, but a few people already asked me about this comparison. And Odyssey is the only new usb-OTG DAC dongle I have.

    Shanling M0 vs S9+DC01 - DC01 has a wider soundstage expansion, but the tonality is nearly identical, maybe with DC01 being just a touch more transparent, but it's hard to notice. I was actually surprised about how close was the tonality and technical sound performance considering DC01 has AK4493 and M0 has ES9218 DACs.

    iBasso DC01 vs VE Odyssey (each one with S9) – Both devices are under $50, with Odyssey actually priced at $30 (per 2.5mm balanced config). They both connect to smartphone (usb-c) and PC (with included USB adaptor). But when it comes to performance, DC01 has a truly balanced design while Odyssey is single ended with a built-in converter. Also, DC01 has a wider soundstage expansion, fuller body more natural sound (Odyssey is brighter in tonality), and better dynamics expansion. Furthermore, I find Odyssey to have a bit more hissing with sensitive IEMs.

    ibasso_dc01-17.jpg

    With Cozoy usb-OTG DACs (connected to Galaxy S9):

    S9+DC01 vs S9+Aegis ($299) – Aegis has a lot higher current drain (drains phone battery faster), has higher output power, stronger hissing, thinner sound (especially mids are brighter and leaner). In comparison, DC01 soundstage is wider (though Aegis has a decent width as well) and tonality is more natural (especially in mids, having fuller body).

    S9+DC01 vs S9+Astrapi ($129) – Astrapi has a thinner more congested sound, while DC01 has a wider soundstage, more natural tonality, better dynamics expansion, better sound layering, and noticeably better sound resolution.

    ibasso_dc01-21.jpg

    Pair up with other DAPs.

    While most of my previous testing was done with DC01 paired up with Galaxy S9 smartphone where it definitely improves the sound, I was also curious to find out if I can do the same with my other DAPs, specifically non-Android ones. To my surprise, it actually paired up with a few DAPs without a problem. In this testing, I was comparing iBasso IT01s connected directly to the DAP vs connected to DC01 attached to the same DAP.

    Hiby R3 (2.5mm bal) vs R3+DC01 - DC01 expands the soundstage, makes it wider and deeper, more holographic, tonality is also improved, making it a little more transparent and more neutral, improves dynamics of the sound as well.

    ibasso_dc01-14.jpg

    Cayin N3 (3.5mm SE) vs N3+DC01 - adds balanced output to N3, and actually has a very noticeable improvement, going from warmer, smoother sound to a more transparent, more layered, more detailed, with better dynamics and more holographic soundstage.

    ibasso_dc01-13.jpg

    Shanling M5s (2.5mm bal) vs M5s+DC01 - DC01 expands the soundstage, makes it wider, and changes the tonality to make it more transparent, more neutral, in comparison to a warmer thicker original tonality of M5s. Btw, in case if anybody is wondering, I wasn’t able to connect DC01 to M0, M1, M2s, or M3s, but it should work with M2x the same way it does with M5s.

    ibasso_dc01-15.jpg

    Conclusion.

    As I mentioned in the intro of my review, DC01 caught me by surprise because I didn’t know what to expect, or the reason why iBasso would even bother to release this USB DAC dongle. Yet, I ended up bringing this little guy with me to work almost daily for the last few weeks because I found it to be very convenient as well as being able to improve the sound quality of my smartphone, especially soundstage expansion and sound dynamics.

    The convenience comes from DC01 becoming a relatively small extension to my IEM cables. The sound improvement comes from a high-res AK4493EQ DAC and a true balanced output design. Plus, with 2.5mm headphone jack, I don’t have to bring extra 2.5mm to 3.5mm adapters and can use my balanced 2.5mm cables connected directly. And I get the same benefits using DC01 with my laptop. For $49 this is no-brainer.
    1. View previous replies...
    2. twister6
      twister6, Jul 16, 2019
    3. alexandros a
      So you do believe that using DC01 with Hibi R3 is better than using R3 alone balanced output soundwise ??True??
      alexandros a, Jul 22, 2019
    4. twister6
      @alexandros a : i'm describing what I'm hearing, comparing 2.5mm bal output of R3 vs DCO1 paired up with R3. And to my ears when it comes to sound quality, there is a noticeable improvement.
      twister6, Jul 22, 2019