The iBasso DC01 is a ‘pint-sized’ fully functional USB-DAC and amplification dongle with a 100% balanced 2.5mm TRRS output jack. It retails for around $50 depending on your location.
Disclaimer: The iBasso DC01 was sent to us as a sample in exchange for our honest opinion. We thank iBasso for this opportunity.
To learn more about iBasso product reviews on Headfonics you can click here.
Xmas 2018 I did something I thought I would never do and that was ‘upgrade’ to a phone with no headphone jack. A Huawei P20 to be precise. It wasn’t a whimsical decision. Earlier in the day, I invested in a DJI Osmo Pocket in the complete confidence my audibly superior LG G7 would be compatible. It was not and cue the panic.
Luckily, across the road, there is a used phone market and with the researched list of phones in my hand, a used P20 seemed the best choice. True enough, the Osmo Pocket works a dream but gone is the jack and in came horrible sounding audio from the stock USB dongle supplied with the P20.
Now I have DAPs so it is not a crushing outcome but I do miss the G7’s flexibility for audio on the go. A better dongle was needed so when iBasso reached out with their latest offering, a balanced output dongle with an AK DAC chipset inside for $50, then it was a no brainer to review.
I have 2 other USB-DAC sticks, but this is the first all-inclusive dongle I have used to date. By that, I mean its ‘plug and play’ without requiring adaptors or additional OTG cables to work on your phone.
The DC01 comes with its own USB-C socket, built-in cable and a main DAC/amp housing as a single entity. Some would call it a “pigtail” solution. The only additional adaptor, a short USB-C to USB-A converter is for use with your PC or Mac. Once connected, the DC01 uses a standard UAC 2.0 sound card chipset for plug-and-play on Mac and Win10 computers
It does not contain its own battery and instead, it draws its power from your phone or computer so battery life is ultimately dependent on your usage combined with your own phone’s battery consumption.
The DC01 uses a single AKM AK4493EQ DAC chipset implementation. That is actually a decent DAC, one that is used by Shanling in their flagship M5s, albeit in a dual-channel configuration. This is their more efficient dual-channel variant so the power drain should be very light in comparison to
I am sort of glad iBasso did not go with an older ES9018K2M type solution or even a single AK4490 so save on implementation costs. Older Sabre chipset ‘treble glare’ tends to produce a harsher sound in my experience, not one you can get into right away. The AK4490 is easier to engineer and filter for but I am told its more power-hungry than the newer AK4493 and out of band noise may be greater.
Decoding capability on the DC01 is excellent. It will handle PCM up to 32BIT/384kHz as well as DSD up to 256 natively. That is on the same level as my more expensive bulkier USB-DAC sticks such as the TAKT Pro and mDSD.
The amp inside the DC01 is a true balanced output design terminating in a 2.5mm TRRS output. If you need a 3.5mm TRS unbalanced option you can grab the DC-02 for around the same price. Since most of my good cables are 2.5mm TRRS this one made more sense.
The power specs are actually not bad for a dongle this size and price at 113mW into a 32Ω load. That’s a good bit higher than my current dongle, the $280 Cozoy TAKT Pro. It taps out at 1.5Vrms or 70mW into the same 32Ω load (3.5mm TRS only). It should be able to power most monitors and light to medium efficiency 30-50Ω headphones. Some of the 100+ dB SPL planar headphones on the market should be ok also with the DC-01.
The DC01 amp stage is also 3 times as powerful on the same load as my oldest USB-DAC stick, the Encore mDSD. I don’t have one of the more expensive Dragonfly variants from AudioQuest sadly, but the Red and Cobalt do output at a higher 2.1Vrms or 138mW but it is never clear to me if they are weighted numbers and if so if it is 32Ω.
The DC01 is 120mm from head to toe including the cable and USB-C termination. Add maybe 10-15mm if you are using the USB-C to USB-A converter for computer use. There is nothing else included in the small retail box but then I suspect you do not need anything else if you are primarily using USB-C. I would have loved to have seen a USB-C to micro-USB converter in there for older phones and DAPs.
Since cable, USB and DAC/Amp module are not detachable, the DC01 seems longer than most other USB-DAC sticks. However, once you slap on an OTG cable to those USB-DAC sticks the DC01 looks a little thicker but ultimately shorter.
The construction seems perfectly fine at this price point also. Both the USB-C termination and main DAC/Amp use the same silver paint finished aluminum allow so it is not a cheap plastic build.
The cable is also a pretty good quality 8-wire copper and SPC hybrid but if you note the cable runs between the USB and DAC then it for a digital signal rather than analog. There is no conversion until the signal hits the base module where the DAC and amp are housed. The wiring is separated or isolated to allow the individual transmission of power, data and of course grounding.
The base of the module houses the 2.5mm TRS output with a small LED diode the lights up blue when there is a formal handshake and it is powered-up.
Despite the DC01 being a plug and play audio device for both phones and Win 10/MAC computers, there is still an issue regarding volume control, specifically for Android smart devices.
The DC01 is UAC2.0 compatible on all Windows and Android devices 5.0 and upwards. However, the majority of Android devices revert to SRC or software-based algorithms for volume control. In short, the volume is controlled on the device side. Software-based volume reduction does not in any way affect noise reduction as should be the case with UAC2.0.
What iBasso have developed is a small app called iBasso UAC which allows the DC01 to bypass any default SRC implementation and instead deliver a 64-Bit digital Bit-Perfect volume control system.
In short, you will get 64 digital steps in your volume control meaning better micro-volume control as well as a lower noise floor when reducing the volume. This places the DC01 on the same functional level as the AudioQuest Red (and Cobalt) which also allow 64 steps.
It has a few handy features also allowing both software or touched based volume control as well as the usual physical volume rockers on your phone. The app will also save your last known memory adjustment when you power up the DC01 again and use the app.
Let’s get this one out of the way right from the start. The DC01 absolutely pulverizes my stock USB-C dongle that came with the Huawei P20. The key is always context here so putting a better performer beside stock gives you an excellent benchmark of just how many layers of ‘suck’ Huawei’s dongle is dipped in.
The DC01 makes the stock dongle sound compressed, thin with way too much odd harmonic presence and sharp partial overtones. The stock isn’t so much bright and energetic but rather harmonically unpleasing with a lack of dynamic range and a lot of texture lost in instrumental notes.
Vocals also fall back and lack a lot of presence compared to the more forward and sweeter and more forward sounding vocal timbre of the DC01. That theme pretty much continues throughout the FR. The DC01 exhibits a fuller low-end, a bit more warmth and sweetness to instrumental notes as well as a treble that is expressive without being overly harsh.
The DC01 dynamic range is also a huge step up on the stock dongle output. For instance, the stock treble of the P20, when it gets going, can sound really hard and jarring but also at times a bit blurry and lacking in separation.
For example, instead of individual quick-firing articulate treble synth notes on seconds 30-60 of my tested track, Vector Hold “Absolute Zero” it sounded more like a single note going up and down in tone and positioning on the stock dongle. It also sounded “strangled” and very lean using the Campfire Solaris.
The DC01 added a bit more body from the bottom up, a bit more warmth and still delivers better separation/articulation on that high-pend treble synth layering.
The staging is also noticeably better than going stock out of the P20 with the supplied dongle. You get more depth and sub-bass power, a fuller and more forward mid-bass presence and a more spacious midrange. There is also more top-end air or headroom.
It is all about the instrumental separation with the DC01 compared to the stock staging for me. The stock P20 dongle sound is really flat and compressed sounding in comparison with not much extension on either end. You will miss detail and imaging cues far quicker than with the DC01.
This is the Achilles heel of the DC01 but it should only affect fairly sensitive monitors. For instance, the high SPL Solaris and Andromeda will show up background hiss but the lower 97dB SPL rated CA Comet is far quieter with a fairly black background. The FiiO FH5 is relatively lower in noise than the Solaris and Andromeda also but not a completely black background and it is about 112dB SPL so right on the line for me.
Once you go up the impedance and drop the SPL level then the hiss starts to drop. The FIBAE range from Custom Art is also very quiet, in particular, the FIBAE 7 we recently tested has a pitch-black background with the DC01. If you are on a tight budget then the 64Ω VE Monks+ with balanced 2.5mm TRRS terminations will have zero issues with noise using the DC01.
If you are using iBasso’s own monitors, the IT03 and IT04 then the DC01 pairing is relatively quiet but not pitch-black. You get some minor non-pervasive hiss on them both but at roughly the same level as the FH5 or slightly lower.
At 113mW into a 32Ω load, the DC01 really should not have too many issues driving most IEMs and portable headphones. I wouldn’t pair these with harder to drive planar headphones and do bear in mind not many headphones come with a 2.5mm TRRS terminations out of the box.
I did try one headphone, the Ultrasone Edition 11 for a couple of reasons. The first is because we can slip on a good quality 2.5mm TRRS 2-pin IEM cable due to its 2-pin connector system. And second, because it is a 32Ω rated headphone, albeit a 94dB SPL.
That SPL was not an issue for the Edition 11. Combining the core P20 volume control with the iBasso UAC app 63-step volume adjuster we rarely had to go above 60% (with the UAC at full volume) on the P20. Without the UAC we were pushing about 80-90% on the P20 volume control to get to an adequate listening level. Put it another way, this headphone goes as far as 90 (volume) using balanced low gain on the 500mW Lotoo PAW Gold Touch.
Cozoy TAKT Pro
We never did a full review of the TAKT Pro but we have been using it extensively in some testing and it was my stick of choice at CanJam in March for testing from my P20.
This is small detachable dongle with an ES9018Q2C chipset and around 70mW (1.5Vrms) of power into a 32Ω load. It is also an unbalanced amp stage design so the 1.5Vrms rating is on the same level as the DC02 from iBasso but lower in output power compared to the DC01.
The TAKT Pro comes with a few cables also to allow it to work from an iOS device, Android (micro-USB only) and USB-A for USB-DAC from a computer. If you need USB-C you will have to buy a small adapter but it will work fine. Like the DC01 it draws power from your connected source such as your computer or phone.
The TAKT Pro does not use any UAC2.0 type app but rather adheres to your phones SRC software implementation. It will work off ASIO drivers for Windows and is universal driver plug and play compatible for both MAC and the latest Windows 10 OS.
The TAKT Pro also has some useful physical button features unlike the DC01 with an onboard volume rocker and a playback control button.
The volume control on the TAKT Pro is total SRC and as such too aggressive and crude for fine controls. It is either loud or not loud enough with no in-between with the P20. Perhaps other phones have a better level of control with the TAKT Pro but certainly, it could do with a UAC2.0 app.
Its noise floor is much lower than the DC01 but for $280 I would be expecting that at the very least. I am impressed however by the pitch black background of the TAKT Pro with the Solaris and Andromeda. The IT04 also has zero noise or just about any monitor that matter will not show up hiss on the TAKT Pro whereas the DC01 results are mixed.
The TAKT Pro is more of a traditional Sabre ES sound with a clean, neutral timbre with a slight treble emphasis. Yes, it has a slight Sabre glare in the lower-treble with a bit more odd-harmonic bias and a slightly drier sound than the DC01 tone. You will hear a slightly hard percussion attack and a bit of vocal sibilance but nothing heavy duty or off-putting from the TAKT Pro.
I have to say that despite the DC01 having the agreeable timbre, the TAKT Pro has the better dynamic range and instrumental separation of the two dongles. You do not really notice that until you throw on harder-hitting tracks such as Grime’s “Butterfly” where the bass definition and texture comes through very well on the TAKT Pro.
Sonic Unity Encore mDSD
We reviewed the mDSD in early 2016 and back then at $99 this seemed a bargain dongle with 32-bit/384kHz PCM and native DSD256 capability as well as a maximum output of 2Vrms or 125mW into a 32Ω load.
Certainly, it is the equal of the DC01 in terms of decoding capability and the slightly more powerful of the two in terms of Vrms though the spec page has a much lowering mW rating of 40mW. It is possible the 40mW is on a higher load or weighting than 32Ω. The mDSD uses a slightly lower-end ES9010Q2M DAC compared to the Cozoy but just as capable as both the TAKT Pro and DC01 for decoding.
Like the DC01 it will work as an OTG dongle and a USB-DAC though the connection system is a bit different. The mDSD is terminated with a USB-A male socket so it works without a cable directly into a computer, however, for OTG and iOS, you do need to buy an OTG female USB-A cable and a CCK for iOS connections.
Just something worth mentioning on the device size. This is much bigger and heavier than the DC01. It is also very wide and can block other USB ports if they are very close together. The mDSD has only has a 3.5mm TRS output and nothing balanced, however, its 3.5mm TRS jack doubles as a very handy 3.5mm optical output for connecting to SPDIF capable DAC/Amps.
It is possible the mDSD has a UAC2.0 63-step control interface via its independent physical volume controls that do not affect the phone side volume setting.
The mDSD does display a high noise floor and some background hiss but using the CA Solaris and Andromeda it does seem the mDSD noise floor is not as high or as pervasive as the DC01. Both demonstrate roughly the same level of noise and very low levels of hiss from iBasso’s less sensitive IT04 hybrid monitor.
The mDSD doesn’t quite have the same level of air as the DC01 but it has slightly weightier instrumental tone. For me, the mDSD has a more analog sounding midrange also which works well with a lot of rock vocal both male and female.
The DC01 has a slight lower-mids dip and a more forward vocal positioning which is very clear when you A/B them using the Huawei P20 as the source phone. The mDSD has the slightly fuller low-end and a bit more lower-mids presence which probably adds to that analog-sounding midrange. The DC01 timbre is a little lighter and sweeter in tone whereas the mDSD is drier with slightly less headroom but a bit more treble body.
I honestly have no complaints with this $50 dongle. It does pretty much everything you need it to do including 32BIT/384kHz and DSD256 decoding, balanced TRRS 2.5mm output and a more than decent DAC chipset inside. Certainly, it blows away my stock dongle and P20 sound for not too many additional greens.
I do have to balance it with its fairly high noise floor with super sensitive IEMs. This may not be the dongle for you if you want to pair a Solaris with it. However, iBasso’s IT04 and IT03 have significantly lower hiss detection and the addition of a UAC2.0 63 step volume control app do give it a degree of complexity and refinement that is hard to beat at $50.
I will be keen to see if the DC01 (and DC02) is part of a growing line of more sophisticated offerings. My older dongles are still competitive but it is not until you hit the $280 TAKT Pro do you geta really pitch-black background and higher dynamic range output. That’s a big gap from $50 that iBasso could well fill in with higher-spec options.
For now, buy a few of these for Xmas gifts or something. Everyone has a phone these days and plenty are Android. Introduce them to a good quality sound from their jack-free smartphone if you can. It won’t break the bank.
- DAC chipset: AK4493
- THD+N: <0.001%(32ohm load, 1.2Vrms)
- Output voltage: 1.9V(32ohm load)
- Output power: [email protected]
- Frequency response: 20Hz-40kHz±5dB
- PCM: up to 32bit/384kHz
- DSD: Native DSD up to 256x
- Weight: 11g