iBasso DC-Tonfa launches as an R2R portable DAC/amp

The iBasso DC-Tonfa was officially announced on July 6 through the e-Earphone blog. The new portable DAC/amp is a collaborative product between iBasso and e-Earphone and will be sold exclusively in Japan. The Japanese headphone specialty retailer contributed to the DC-Tonfa’s sound tuning while also influencing its design and included accessories. Below are all the details about iBasso’s latest release for the Japanese market.

Update (August 5): The iBasso DC-Tonfa is now available in the international market through the official iBasso store on AliExpress.

How the collaboration between iBasso and e-Earphone led to the creation of the Tonfa

The collaboration between e-Earphone and iBasso originated during the Winter 2025 Potafes (Portable Audio Festival). The project was initiated by Yudy, a member of e-Earphone’s public relations team.

During Potafes, Yudy asked a representative from MUSIN, iBasso’s official distributor in Japan, whether it would be possible to develop a collaborative product with iBasso Audio. The MUSIN representative replied that iBasso was already developing “a product equipped with an R2R DAC called Tonfa.” Since the project was already underway, the idea of turning the Tonfa into a collaborative model was proposed.

The collaboration request did not come out of nowhere. In an interview published on the e-Earphone website, Yudy explained:

“This entire collaboration started simply because I genuinely love iBasso Audio. At the same time, I was able to incorporate both the aspects I admire most about the brand and a few improvements that, in my opinion, could make it even better.”

The design and accessories of the Tonfa

According to Yudy, the Tonfa’s construction was based on the iBasso Nunchaku. As a result, it features the same 0.96-inch OLED display, along with tempered glass panels on both the front and rear. Internally, it also shares several hardware similarities with the Nunchaku, including the use of four BUF634A buffer amplifiers.

To personalize the product, Yudy requested that iBasso use a black volume knob. This decision was intentional, as he also requested the addition of a black color variant alongside the originally planned red and blue versions.

Naturally, the black Tonfa needed a matching black protective case. Every color variant of the Tonfa includes a black MagSafe-compatible protective case with integrated magnets. At the center of the magnetic ring is the e-Earphone × iBasso Audio collaboration logo.

The collaboration logo also appears on the tempered glass rear panel of the DC-Tonfa.

Recommended optional accessory

To further improve the DC-Tonfa’s sonic performance, both e-Earphone and iBasso recommend using the iBasso CB19C cable. According to the companies, the practical improvements include tighter bass response and a blacker background resulting from reduced electrical noise. This is made possible by separating the power delivery path from the data transmission path.

The iBasso CB19C is a USB cable that splits into two separate connectors: one connects to a power bank while the other connects to a smartphone. This design provides a more stable power supply while minimizing interference with data transmission.

It is worth noting that the CB19C is not included with the iBasso DC-Tonfa. It is sold separately through iBasso’s official store on AliExpress.

The development of the Tonfa’s tuning

Although many audio enthusiasts actively seek products equipped with R2R DACs, Yudy admitted that he had never been particularly fond of them. According to him, he does not enjoy the “classic” sound typically associated with R2R architectures, which he describes as being “extremely warm and smooth.” For that reason, he initially believed it would be very difficult to achieve a tuning that matched his personal preferences.

Yudy explained that he received three Tonfa prototypes, each featuring a different sound tuning. According to his account, as soon as he listened to one of them, he immediately thought:

“This is it!”

That particular tuning ultimately became the final sound signature of the production model.

Fully balanced R2R DAC architecture

For the DC-Tonfa, iBasso developed an in-house 8-channel fully balanced R2R DAC. The DAC is built using a total of 312 Viking thin-film resistors, selected for their high precision and low temperature coefficient.

iBasso describes the Tonfa’s R2R DAC as follows:

“Thanks to its fully balanced 8-channel differential R2R architecture, zero-cross distortion and low-level linearity have been significantly improved. As a result, the DC-Tonfa preserves the characteristic texture of R2R DACs while delivering excellent detail retrieval and exceptionally refined sound reproduction.”

To minimize resistor temperature drift while reducing distortion and noise, iBasso implemented a calibration system consisting of 60 precision resistors combined with FPGA-based correction algorithms.

Regarding this supporting system, iBasso states:

“A hardware compensation network composed of 60 high-precision resistors, combined with an FPGA-based calibration algorithm, carefully controls resistor tolerances and temperature-induced variations. The result is significantly improved linearity and channel matching while preserving the characteristic sonic qualities of an R2R DAC, now with greater transparency, purity, and realism.”

High output power capable of driving most headphones and IEMs

The DC-Tonfa delivers even higher output power than the iBasso Nunchaku.

With 800 mW into 32 ohms from its balanced output, the portable DAC/amp is capable of driving virtually all in-ear monitors (IEMs) as well as the vast majority of over-ear headphones with ease.

What does the iBasso DC-Tonfa sound like?

Yudy described the Tonfa’s sound signature as follows:

“It delivers full-bodied vocals, an intimate presentation, and a spacious soundstage, resulting in an elegant and highly enjoyable listening experience. If someone asked whether it sounds exactly like a traditional R2R DAC, my answer would be ‘not entirely.’

It preserves iBasso’s signature slightly cool tonality, with an emphasis on vocal body and a very distinctive sense of space, while also incorporating the smoothness and spatial presentation that only an R2R DAC can provide.”

Hama-chan, another member of e-Earphone’s public relations team, described the Tonfa’s sound as follows:

“The bass has very little muddiness. It retains its impact while remaining clean and well-controlled. As for the upper midrange, perhaps because of its balance with the bass, I wouldn’t say it’s completely free of peaks, but its extension sounds natural. Since I’m a big fan of bass, I was genuinely impressed by the quality of its texture. I also think it pairs better with tracks that have strong rhythmic energy than with softer, more subdued music.”

Meanwhile, Seme-chan, a member of e-Earphone’s review team, characterized the Tonfa’s sound in the following way:

“The impact and weight of the bass are impressive. The texture of acoustic guitars, as well as the natural body of vocals, is reproduced with remarkable fidelity, convincingly conveying the feeling of a live performance. The treble has been softened just the right amount. Even at higher listening volumes, the sound rarely becomes fatiguing or harsh. The soundstage maintains a good sense of width without ever feeling congested. Overall, this is a DAC/amp that prioritizes musical enjoyment, impact, and three-dimensionality over analytical listening.”

Support for the iBasso UAC app

The iBasso UAC application is available for Android and as a web-based application that can be accessed through a browser on a computer. The DC-Tonfa is fully compatible with iBasso UAC, allowing users to access and configure features including:

• Digital filters
• Volume control
• Channel balance
• Equalizer
• Presets
• Gain

To access the web version of iBasso UAC, simply click this link.

iBasso DC-Tonfa compatibility

The DC-Tonfa is compatible with the Nintendo Switch and PlayStation 5 (PS5) thanks to its support for USB Audio Class 1 (UAC1).

Additionally, because it also supports USB Audio Class 2.0 (UAC2), it can be connected to the following devices:

• Android smartphones and tablets
• iPhones and iPads (iOS and iPadOS devices)
• Windows PCs
• macOS computers, including MacBooks and iMacs
• Linux computers

It is important to note that the iBasso UAC application is not available for iOS devices, including iPhones.

iBasso DC-Tonfa specifications

General specifications

• Amplification stage: Two Texas Instruments (TI) dual operational amplifiers + four BUF634A buffers
• Chassis material: Aluminum alloy
• Console compatibility: Nintendo Switch and PlayStation 5 (PS5)
• Controls: Multifunction rotary knob for volume adjustment and menu navigation
• DAC: In-house developed 8-channel R2R DAC
• Digital inputs: USB-C and coaxial S/PDIF
• Dimensions: 61 × 34.6 × 15 mm
• Display: 0.96-inch OLED
• Headphone outputs: 3.5 mm single-ended (SE) and 4.4 mm balanced
• Operating system compatibility: Android, iOS, Windows, macOS, and Linux
• Power supply: 5 V via USB-C
• USB Audio support: UAC2.0 and UAC1.0
• Weight: 45 g

USB audio specifications

• Native PCM playback up to 768 kHz
• Native DSD playback up to DSD512

3.5 mm single-ended output specifications

• Signal-to-noise ratio (SNR): 118 dB (AES17, A-weighted, 20 kHz)
• Dynamic range: 115 dB (AES17, A-weighted, 20 kHz)
• THD+N: 0.0056%
• Output power: 219 mW into 32 Ω
• Output level: 2.6 Vrms (High Gain), 1.3 Vrms (Low Gain)
• Channel separation: 121 dB
• Frequency response: 10 Hz–22 kHz (-0.3 dB), 10 Hz–40 kHz (-0.8 dB)
• Output impedance: 0.2 Ω

4.4 mm balanced output specifications

• Signal-to-noise ratio (SNR): 122 dB (AES17, A-weighted, 20 kHz)
• Dynamic range: 123 dB (AES17, A-weighted, 20 kHz)
• THD+N: 0.004%
• Output power: 800 mW into 32 Ω
• Output level: 5.2 Vrms (High Gain), 2.6 Vrms (Low Gain)
• Channel separation: 124 dB
• Frequency response: 10 Hz–22 kHz (-0.3 dB), 10 Hz–40 kHz (-0.8 dB)
• Output impedance: 0.5 Ω

What’s included in the box

The iBasso DC-Tonfa package includes the following accessories:

• Exclusive MagSafe-compatible protective case
• USB-C to USB-C cable
• USB-C to USB-C L-shaped cable
• USB-C to USB-A adapter
• Quick Start Guide
• Warranty card

Release date, pricing, and availability

The iBasso DC-Tonfa is now available in Black, Red, and Blue for ¥54,450 (approximately US$335) through the e-Earphone online store. In early August, the DC-Tonfa was also launched in the international market for US$372.35 through the official iBasso store on AliExpress.