iBasso DC04Pro Review

In this article, we review the iBasso DC04Pro, the new dual-chip DAC/AMP dongle from the brand, available for just $119 USD.

Disclaimer: the iBasso DC04Pro was sent to us, free of charge, by the brand in exchange for our honest opinion.

About iBasso

Founded in Shenzhen, China, more than ten years ago, iBasso has been producing DAPs, DACs and IEMs for audiophiles. And over time, they’ve become one of the most acclaimed brands for those seeking budget-friendly, but high-performance gear.

And if the iBasso DX320 stole the show, with stellar sound performances and snappy UI, putting the brand back in the spotlight, they’ve also released great IEMs like the iBasso IT04, and an excellent set of usb-key-sized DAC with the DC01, DC02, the whole new DC03Pro – reviewed a few weeks ago – and more importantly, the DC06.

This one remains, to this day, one of my favorite portable DAC/AMP, thanks to its small size, bulky but catchy design, and excellent performance-to-price ratio. But, a year later, the market has become even fiercer, with competitors from established brands like FiiO, HiBy, Hidizs and newcomers like ddHiFi.

So, iBasso had to catch up, and came with two new models: the DC03Pro, a new DAC/AMP, slimmer, fancier, more affordable, packing a dual Cirrus-Logic CS43131 chip with not-too-shabby performance’s. A device that I found “impressive, despite its compact size, packing enough punch to drive most IEM and headphones” – full review available here, if you want to know more.

And following that last review, today we get its big brother, the iBasso DC04Pro. A DAC/Amp with twice more power, even less distortion than before, and a dual output (3.5mm + 4.4mm) to drive hungrier headphones – for twice the price. The perfect one? Time to find out.

Design & Build Quality

Casing

If slightly thicker than the DC03Pro, the iBasso DC04Pro remains a lot thinner than the bulky-but-sexy DC06, which looked like a mini CPU-Radiator. This new DAC/Amp from iBasso keeps the same sleek, streamlined, design and remains almost two times smaller than the USB-Dongle flagship. Sure, the DC03 Pro remains the epitome of portability, but honestly, the physical difference between the DC04 Pro and its entry-level brother remains negligible on a daily basis.

End to end, the new DAC is just 59m long, 23.4 mm wide, and 12.1 mm thick, for just 21 g on the scale – twice more than the DC03Pro. To those measurements, you can add the USB-C cable, or USB-C to 8-Pin if you’re using an iPhone like me. Thanks to that, the DAC can easily be carried in a jeans pocket, a jacket, or it can simply be attached to your phone if you’re comfortable with QI-wireless charging.

Entirely made of CNC-milled aluminum, the case is covered on each side with tempered glass, embracing all the codes of modern tech apparel, giving the iBasso a strong visual appeal. Sure, I miss the bulky design of the DC06, but I’m pretty sure that the DC04 PRO design will appeal to more people – at least those who dislike thick DAC/AMP – and you win physical volume buttons!

Again, from afar, you could easily mistake the DAC for an USB-Key, or a hardware crypto-wallet, like the new Ledger Nano, especially with the two control-volume buttons, sitting on the side.

Build Quality

Once again, this new unit is absolutely flawless in terms of build quality. It doesn’t scream “POWER” like the DC06 could, but it also feels a little more beefier than the DC03 Pro. The bigger case and 4.4mm Pentaconn output clearly contributes to that, enhanced by the hollow design of its volume guard, perfectly bevelled angles.

Available in two colors – black or blue – the iBasso DC04PRO is made of an anodized, CNC-milled aluminum body, topped by superb glass panels on each side. It’s a screw-less design with two headphone outputs – 3.5mm TRS + 4.4mm Pentaconn sockets – on one side, USB-C on the other end, and volume buttons on the left side (or right depending on what you consider the top is). Everything looks and feels nice to touch and hold, reminding me of the old NuPrime Hi-mDAC, another great pocket DAC, but enhanced.

For the sake of this review I took out my iFi Go Blu, another lovely DAC/Amp with volume control embedded, and clearly, the iBasso gave me a better impression in hand, at least in terms of perceived quality (still love the iFi though). It feels almost as premium as Maktar’s X2 Lightning Dongle, which remains my top choice for whoever wants a flawless device, with its matte-black tubular frame, but the iBasso DC04PRO  aims at a different public, craving for an entry-to-mid-level DAC, with mid-to-high-level performances…

Again, I got spoiled by the DC06, which became one of my go-to devices, paired with the Shanling MG600, and switching for the DC04PRO, like the DC03PRO last time, felt like a downgrade – essentially due to the weight difference. But over time, this lovely dongle kind of grew on me, and like the ddHiFi TC44C, getting 4.4mm Pentaconn for my in-ears, on the go, is a real wonder.

All in all, a very nice piece of work!

Bundle

Quick word on the bundle: it’s dire, but not more than other models. It comes with an USB-C to USB-C cable only, but you can also order the CB18 premium USB-C to USB-C alternative – the one seen in my pictures – and an USB-C to 8-Pin connector for your iPhone. The brand was kind enough to bundle both USB-C to USB-C cable and USB-C to Lightning cable with my review sample, but I don’t know if the commercial version comes with both cables too.

Alternatively, you could get a Lightning to USB-C adaptor like the ddHiFi TC28i, and plug it between the DC04PRO and your iPhone. It’s up to you!

Comfort and Specifications

Daily use

The iBasso DC04PRO is extremely simple to use.

You plug it into your phone, insert your headphone jack, and you’re good to go. There were no issues with my iPhone 13 Pro Max + TC28i + DC04PRO, or with my MacBook + CB18: each time, the iBasso was immediately recognized by the source, and music came out almost instantly.  On Windows, I had to wait a minute, until the OS got the right driver but after that, it worked flawlessly.

In parallel, there is the UAC iBasso software. Made for the DC0X series, this software enables UAC 2.0 controls, to unlock the full 100 steps hardware volumes, 5 digital filters, 3 gain levels, 2 Output mode and L/R balance – something that many listeners seem to ask for. But as an iOS user, I didn’t have the chance/will to try it and felt already grateful to get additional volume control on my iPhone, thanks to the DC04PRO.

A feature that’s still missing on all and every USB-DAC dongle, apart from this one, the HiBy FC04 and NuPrime’s Hi-mDAC. Last but not least, you can spot a tiny LED light on the top side, indicating the current sampling rates:

• red for standby, when no music is playing
• green for PCM files
• blue for DSD files

Let’s take a quick look at the specs now.

Specifications

Like the DC03PRO, the iBasso DC04PRO ditched ESS-Tech, for the good old CS43131 from Cirrus-Logic – and not one, but two in dual-mono mode. It’s a great chip, found in many mid-to-high-end devices, like the Astell&Kern SR25, or the Cowon Plenue R2, packing a lot of powers and many great features like:

• an integrated GND-centred with a Class H headphone driver able to output 30mW per channel at 32Ohms
• full PCM decoding up to 32bit / 384kHz and an advanced 32-bit oversampled multi-bit modulator with mismatch shaping technology
• Improved output level up to 2 VRMS into 600 Ω headphones

To that, iBasso added its own “sauce”, to enable the full potential of the DAC, and furthermore, output more power with a lower floor noise. So, upstream of the dual CS43131 chips, the brand added its own USB-receiver chip, combined with an FPGA controller and a KDS femtosecond oscillator, something we’ve already seen in previous models, like the DC05.

On top of that, the power supply gets a completely redesigned synchronous DC-DC converter, feeding a Texas Instruments Low-Noise Charge Pump Plus LDO – minimizing power consumption – and a >100dB PSRR LDO that communicate directly with the DAC. Long story short, on paper, the iBasso DC04PRO drags half less power than other DAC and outputs more current. Numbers? Only 650mW in balanced mode, and 550mW in single-ended mode. You can even activate the power saving mode, that lowers the grand total to just 410mW!

But the real feat this time isn’t from what we hear, but what we won’t: noise floor. The brand was notoriously known for its noisy players, from the old DX80 up to the DX220. But, since the iBasso DX300 – and further more on the DX320 – all of that changed, and every device has been an improvement since, with the DC04PRO reaching nanoVolt level of noise – 900nV or 0.9uV, topped with a 131dB of Signal to Noise Ratio.

Cherry on top, the DC04PRO uses a dual set of RT6863 opamp from Ricore, to create a 4-way, fully balanced amp with an output current of up to 100mA, working at a 10V voltage swing. Powered by my iPhone only, the iBasso DC04PRO is capable of outputting 280mW @ 32 ohms, in TRRS mode, while maintaining a supremely low THD of just 0.00013%(!).

Finally, for the nerds out there – like me – here are the full specs.

Technical specs

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