Review Date: 16 January 2022

SPECIFICATIONS

• Dual ESS Sabre ES9219C DAC chips
• iBasso Custom Quad DAC+ Technology
• Time Domain Jitter Eliminator
• HyperStream III architecture
• MQA Decoding
• 32-Bit/384kHz PCM decoding
• Native DSD256 decoding
• THD+N: <0.00056%
• Output voltage: 2Vrms(300Ω load), 1.73Vrms(32Ω load)
• Output power: 140mW@16Ω, 93mW@32Ω
• Frequency Response: 20Hz-40kHz
• Dynamic range: 121dB
• SNR: 121dB
• Output Impedance: <0.5Ω
• Weight: 9grams
• Length: 105mm
• Interface: Type-C, 3.5mm Single Ended

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Test Equipment

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LISTENING EQUIPMENT USED IMPARTED HUGE INFLUENCE TO SOUND IMPRESSIONS & RATING

iBasso DC05 is a direct successor to the popular DC03. The major change, iBasso opted to shift from Cirrus Logic CS43131 (dual) to the ESS Sabre camp, with ES9219C (dual). This I believe has a lot to do with iBasso wanting to integrate MQA into their DC lineup – with ES9218C being natively capable of MQA unfolding. Otherwise the look and feel of DC05 build is practically identical to DC03. But what’s inside that matters, yes?

Build, Functions, Usability

True to DC series legacy, DC05 is a very compact Dongle, with minimalist approach that favors fixed USB C cable instead of the more popular detachable option. Now this is a mixed bag for some. While I welcome the simple design, many would also find this a bit worrying because if anything goes wrong with the USB jack, then it is pretty much a dead end, unlike some other Dongles where you can swap in fresh new USB C cable replacement.

Other than that, there’s a single led indicator that will tell the user at which resolution the unit is processing the audio feed. As would be normally found on other Dongles, Green being PCM and Purple being MQA.

Despite being devoid of any hardware volume adjusters, iBasso claimed that DC05 has an internal design that will allow for precise volume adjustments (64 Steps on UAC2 compliant devices). I can attest that this is fully operational on my devices. A much welcomed innovation by iBasso as it allows for fine tuning of loudness levels.

On November 22, 2021, iBasso released a new Firmware update for DC05 which can be downloaded here: LINK

Initially I have issues updating my DC05, it kept on failing no matter how many times I tried. And then with the help of ChiFi Audio Reviews group members as per discussed here (FB Link), all it took was to type in 001 instead of the value as per instructed by iBasso on their update document. I am pretty satisfied with it now. As far as I can tell, the FW was meant to implement “Disable ES9219C’s automatic clock gearing to improve the Inter-Modulation Distortion (IMD)” – as per iBasso statement. Otherwise I can’t tell the FW introduce any significant sonic change to an already great sounding unit. But, I do sense that there’s subtle improvement on lower frequencies presentation now at which it impacts Bass responses (more details on this later).

DC05 exhibits great usability for both USB Exclusive mode (UAPP) and Tidal Masters MQA (USB Exclusive Access). As for MQA, the unfolding of Masters done flawlessly without any hint of issues that I have observed with Dongles of past year (2021), where sometimes I can hear clipping and artifacts during playback. So this is a good thing indeed for DC05.

For endurance test, DC05 scored 6 hours of continuous play on my Sony Xperia X Compact (Android 8, 2700 mAH battery, UAPP bitperfect mode, driving TRN VX Pro). This is pretty much a decent mileage on par with the likes of Cayin RU6 and Lotoo PAW S2.

Sound Impressions

iBasso DC05 is one very well rounded DAC/Amp. The sound signature of DC05 I regard as naturally balanced with slight boost on the lower frequencies. It is not exactly neutral. Compared against the older DC03, that older unit sounds a bit more aggressive, brighter, edgy and euphonic. DC05 in comparison is a refined improvement on the same tuning approach by iBasso – now with less aggression, better controlled brightness, less edgy attack and closer to neutral timbral balance.

However I would still say that DC05 lacks the analogue organic touch that I prefer. Dynamic presentation and transients are clean and clear, but ultimately still digital sounding to my ears. This is especially apparent when paired with Etymotic ER4SR, Shure KSE1500, Fostex T40RP MK3 and Beyerdynamic DT880. I would even say that if paired with highly resolving partners, the tendency is to veer towards that cleanliness and thus sacrificing analogue touch in the process. I am quite picky on this subject, being analogue sounding is what I consider as enjoyable – analogue and organic presentation is all about being believable sounding that reflects realism. But then this is just me with my preference of sound signature. Otherwise for those preferring clean and crisp presentation, DC05 will deliver in spades. I must also note that on this subject of dynamics, timbre and tonality, the best output I get from DC05 is from TRN VX Pro, TIN HiFi T3+, VE ZEN 2.0 SLQ and VE Asura 3.0 FE. These pairing partners does exhibit better synergy with DC05, the output being closer to that organic natural presentation that I adore so much. What this translates to me, DC05 seems to prefer warmer sounding partners, pair it with something natively bright and exceedingly resolving IEMs like ER4SR or Shure KSE1500, there’s a tendency for the notorious ESS pinna glare to emerge.

On the subject of ESS “pinna glare”, this unfortunately is a widespread issue observed from many ESS DAC implementation that I have tested so far. And I have tested over 50 units of Dongles running on ESS. Prime examples of well tuned and balanced implementation for ESS can be had from Apogee Groove, Questyle M12, REIYIN DA-Plus, THX Onyx, ASUS ROG Clavis, Audirect BEAM 2S, HiBy FC5 and Shanling UA2. The most typical bright pinna glared ESS implementation being HiBy FC3, Zorloo Ztella, E1DA 9038D and Audirect BEAM 2SE (not limited to these). DC05 thankfully does not have this issue, at least not severe enough, and this place DC05 somewhere between Questyle M12 and HiBy FC3 – not a bad option at all eh?

As mentioned earlier, I stated that DC05 is a naturally balanced Dongle with a touch of lower frequency boost. What this mean, DC05 audibly has that Bass hump when tested with my FOSTEX T40RP MK3 and Shure KSE1500, both of which capable of resolving every ounce of details, textures and imaging especially for Bass responses. Compared against my reference Dongle of CEntrance DACport HD, I can clearly hear the pronounced boost of Bass on DC05 that is elevated beyond what I consider neutral. Now this is not a bad thing especially for those enjoying dense and textured Bass performances. But for Diffused Field Neutral geeks (me included), this is something that can prove detrimental to perceived neutrality. Otherwise, Bass responses of DC05 is decidedly fast, textured, impactful and clean. With more preference on crisp decays over smooth lingering edges.

For the rest of the sound spectrum, DC05 exhibited great Mids presentation. Instruments and vocals being clean and crisp with mature dynamics. However I must note that for some peaky vocals, Alison Krauss for example – she has that natively sharp Soprano voice and when she gets into crescendo, I can hear something that is borderline sibilant. The good thing is, it never actually went all out SSS sibilant, just almost there, haha. On the other hand, the Contralto vocals of Diana Krall sounds as rich as how it is meant to be, so does the Baritone of Nick Cave and Morrissey. Works great too for the Jazzy vocals of Sinne Eeg, her singing wholesome and engaging, perhaps just lacking a bit of organic warmth but I would not complain too much on it already. The overall attack and transients of Mids I will regard as polished and crisp, clean and convincing imaging. I would have prefer to have a bit more of smoothness, otherwise without going into nitpicking mode, DC05 does it admirably still.

As for the highs, DC05 must be commended for exhibiting great control to keep Treble well presented. It is as sparkly and vibrant as can be expected from a well tuned ESS Sabre DAC. My only complaint here being the lack of air due to preference towards crispy decays. Yes the decays and extension are there to be heard, it just does not have pronounced bias to airiness. For as long as DC05 is paired with “warmer” partners, Treble is totally free of any fatigue element, but can be a bit edgy for natively bright sounding partners.

Technically, overall DC05 is a decent performer. The caveat being Soundstage seems to offer average size width and breadth. I am not too surprised with this as it is quite common for most ESS based DACs. Tall and narrow, it’s the same story for many other ESS Dongles. Placement of instruments seems to be closed in – while not being muddy, I wished that there’s a bit more of space to it. What is great, imaging is sharp and clean, layer separation remained succinct. Spatial imaging as holographic depending on how competent the partner is. Details handling being great too, with my ER4SR, T40RP MK3, KSE1500, TRN VX Pro and DT880 being able to pick every Micro details available in the recordings.

Driving Power

As part of #donglemadness 2022 standard procedures, driving tests with two of my most difficult to drive Headphones. My desktop stack of iFi ZEN DAC V2 + ZEN Can (15.1 Vrms) used as a reference to ascertain how close DC05 able to drive those two juggernauts. With the ZEN stacks providing 100% experience, this is how DC05 compares:

IBASSO DC05 3.5MM SE

• Fostex T40RP MK3: 65% (Vol 96/100)
• Beyerdynamic DT880: 60% (Vol 98/100)

The percentage being indication of how close RU6 to that iFi ZEN Stack. Of which the criteria for comparison as follows:

• Listening loudness (proper level)
• Dynamic transients and density
• Headroom spacing and staging
• Imaging strength
• Details articulation

The percentage scored by DC05 is decent. While not being particularly impressive it is still very usable with those two headphones. Putting aside being critical and just focusing on music enjoyment, DC05 performed admirably still. In fact I would admit that when listening to my DT880, I wasn’t bothered much by the lighter dynamics presentation, the tonal balance of DC05 remained intact and that’s enough to allow me to enjoy my music casually.

The limit of DC05 driving power for proper fidelity is best limited to 320 Ohm. As proven with VE ZEN 2.0 SLQ which sounds satisfyingly great to my senses. It is rich and engaging. Great dynamics density with proper level of vibrancy. The same can be said of 155 Ohm VE Asura 3.0FE.

VERDICT

Overall, iBasso DC05 proved to be a great Dongle with just minor quirks. Cons that I consider as non deal breaker. The strength of DC05, being well balanced at presenting crisp, clean and mature sound. It is assuredly a better unit than the predecessors of DC03 (and even DC04). Less aggression and more articulation. The key factor for DC05 is all about pairing it with the right partners. Preferably something that is not already natively bright sounding.

⭐⭐⭐⭐ ($53)

Best Pairing: Prefers natively warm sounding partners

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