iBasso DC Tonfa and KLEE 2 KISEKI

High-End Sound on a Budget!

PROs: Tonfa – big soundstage expansion, neutral, resolving, fuller body, dynamic tuning, black background, high output power, easy-to-navigate OLED screen and app support for all the settings, solid build, cool leather case with magnetic (MagSafe) rear panel, quality USB-C/Lightning OTG cables; KLEE 2 – balanced tuning with a natural, revealing tonality, solid, high-quality build, modular cable (3.5mm and 4.4mm connectors), lots of eartips, all for under $80.

CONs: Tonfa – no built-in battery or Bluetooth connection if that is what you are looking for; KLEE 2 – for this price, can’t think of anything.

These products were provided to me free of charge for review purposes in exchange for my honest opinion.

The manufacturer’s website: iBasso. It can be purchased from authorized retailers, such as Bloom Audio.

Intro.

iBasso has been on a roll year after year, spoiling us with so many new releases. 2026 was no different, but I started to notice a slightly different pattern: a less saturated, wider variety, in function and pricing, of new audio toys catered to the portable, transportable, and desktop crowd. I know that I have been focusing more lately on their higher-end products, having the pleasure of reviewing their 20th-anniversary flagship releases, the DX340Max Ti DAP and Epitome IEMs, but then I took a step back and, out of curiosity, decided to shift my attention to the other end of the iBasso release spectrum after they announced the R2R DC Tonfa USB/DAC dongle ($359) and entry-level single DD, KLEE 2 IEMs ($80).

As I mentioned before, dongles have become alternatives to entry-level DAPs, and some audio gear manufacturers have elevated their performance to mid-fi and even summit-fi levels at a fraction of the DAP prices. Also, while I don’t have many references for comparing chi-fi price-level IEMs, the original KLEE release was a pleasant surprise, and yes, I was curious to hear where they are going with the follow-up. Tbh, I wasn’t even aware of the KLEE 2 release until Paul suggested I check it out, just for feedback, without any review expectations. But it impressed me enough to include it in this write-up as well.

I did receive both a few months ago, but due to overwhelming commitments at work and home, and some issues with one of my ears that took me a bit of time to recover from, I only finished them recently. Don’t worry, this won’t be one of my long reviews, but I will cover both products in parallel, with enough detail to give you a clear picture of each. So, let’s get right to it and read what I found after spending time with two of the latest iBasso budget-friendly releases: the DC Tonfa dongle and KLEE 2 IEMs!

Unboxing and Accessories.

Tonfa has a typical compact box packaging I have seen with many of iBasso’s other dongles and some of their IEMs. On the sleeve cover, aside from the printed product name “DC-Tonfa, 8CH R2R DAC & AMP”, I also found a surprising reference to iBasso Audio x E-Earphone, a major Japanese headphone retailer, which I later learned was because this release was a collab between these companies. Inside, you will find the device itself, a cool leather case with a MagSafe-compatible magnetic attachment on the back, two quality OTG cables inside a small velour baggie, USB-C to USB-C and USB-C to Lightning (to cater to older iPhone users), and a USB-C to USB-A adapter for desktop use with the included OTG USB-C cable.

I absolutely loved the provided leather case, with its clever, minimalistic, magnetic attachment on the back. Instead of making it bulky with a full circular magnet, they included only the top and bottom segments of the “circle,” covered with leather so they won’t scratch your phone, and I found them strong enough to withstand normal wear and tear. Of course, if you shake it strong enough, it will fall off, but for casual use, it provided enough attachment force to stay secure on my UAG case with Galaxy S25.

KLEE 2, also known as KLEE KISEKI, is released under the iBasso Jr brand, which is often associated with their budget, entry-level releases. I hate using “chi-fi” to describe iBasso products, but it clearly targets the chi-fi audience; however, it felt rather premium. The packaging features a sleeve with colorful artwork on the front and detailed specs, including an FR graph, on the back. Under the sleeve, in a compact cardboard box, you will find partitioned sections containing IEMs, a modular cable (with 3.5mm and 4.4mm connector tips), 3 sets of quality eartips (a total of 9 pairs in S/M/L sizes), a white, synthetic material, rectangular storage case with a magnetic cover, and a detailed quick-start guide.

The cable features a colorful, flexible, blue-and-white (with a touch of black) nylon-braided paracord-type outer jacket, and cable hardware similar to the original KLEE. Here, the headphone plug has a 4-pin socket, and you have a choice of 3.5mm SE or 4.4mm BAL tips, which attach securely by aligning them with a guide pin and tightening the connection with the plug’s threaded housing. The matching silver-grey metallic finish Y-split, chin slider, and 2pin connector housing with Red (R) and Blue (L) markings are the same as in the original KLEE, and I’m happy to see iBasso continue using 2pin connectors, unlike their earlier days mmcx connectors. Also, while the cable material wasn’t provided, I wouldn’t be surprised if it is still an oxygen-free copper, silver-plated wire, as in the original KLEE release.

Overall, the packaging is compact, and all the included accessories are practical, without any unnecessary fillers.

Design and under the hood.

I will cover both in parallel here as well.

DC Tonfa

Starting with a star of this review, Tonfa, it’s a compact, portable, aluminum alloy, lightweight dongle, measuring about 60 mm x 35mm x 15mm, with a footprint very similar to DC Elite and Nunchaku – a familiar rectangular shape with a flatter left side, rounded right side, 3.5mm/4.4mm ports at the bottom, and a USB-C port and volume wheel at the top, to the right of the port. Once powered up, you will find a 4-line OLED display with all the essential info, such as volume level, gain, and filter setting, sample rate and bit depth, available in a clear view. The volume wheel also doubles as a push-button: press/hold it to enter the Settings menu, use the scroll wheel to step through settings, and press it again to cycle through available options under each setting.

The Settings are as follows: Filter (D1-D4, and D5-NOS), Gain (H/L), Coax (on/off to enable 3.5mm digital optical SPDIF output), Balance (between L-R sides), Rotation (flipping the display view 180deg), Volume (off-screen volume knob operation), UAC version (1.0 or 2.0 for compatibility), Backlight (screen time: always on, or per selected timeout), Version number. While it’s not an issue going through all these settings on the device itself, you also have the convenience of accessing everything through the free iBasso UAC companion app, which some might find easier to navigate on their larger smartphone screen. But it is also important to note that as you move Tonfa between smartphones, tablets, or laptops, you don’t need to worry about the app (especially if you are using it in a desktop setup from a laptop) and can access and change all the settings directly on the dongle.

Under the hood of this compact dongle, you will find an advanced design with a true 24-bit, 8-channel, fully differential R2R DAC, featuring 312 ultra-low-temperature-drift Viking metal-film resistors, managed by an iBasso proprietary FPGA algorithm that controls decoding precision and timing to reduce jitter. I know this is a mouthful of a design description. Still, it also shows how much attention goes into the design, even if it is “just” a small dongle that turns your smartphone into a high-end DAP supporting hi-fi PCM playback up to 768kHz and Native DSD playback up to DSD512.

But it’s not just an advanced R2R DAC dongle; it’s also a device with very powerful output thanks to its AMP design section. The amplification stage is handled by two high-performance TI dual OP-AMPS and four BUF634A buffers, capable of outputting up to 800mW per channel from a 4.4mm BAL output, in high gain, at a 32ohm load. It was powerful enough to drive even some of my demanding headphones and IEMs, and performed well with very sensitive IEMs, where the background waterfall hiss was rather mild.

KLEE 2 KISEKI

These IEMs feature stainless steel shells, available in either mirror-polished or blue finishes. The shell is very compact, with a manageable heft due to its SS construction, and it has a very comfortable fit. The nozzle is removable and made of brass, unlike the original steel KLEE nozzle. Considering the removable/replaceable nature of the nozzle, I was a bit surprised that they didn’t include a few additional pairs with different screen filters to fine-tune the sound further. But you have to keep in mind these are sub-$80 IEMs, and you probably need to draw the line somewhere. Furthermore, the removable nature of the nozzle makes it convenient to clean the earwax buildup, if any accumulates over time.

Shells feature a dual-vent system, with one pinhole vent next to the 2pin connector socket and the other, larger port covered by a screen (red on the right earpiece and blue on the left), next to the nozzle on the inner side of the shell. Perhaps I don’t have as much experience with current chi-fi releases, but I’m aware that many manufacturers try to cut corners to meet their target price. Here, the build and finish of KLEE 2 didn’t feel budget at all.

Inside the shell, these IEMs feature a single 10mm dual-magnetic-circuit Dynamic Driver with a Lithium-Magnesium alloy dome diaphragm. While there is less information available about the KLEE 2 driver design, I assume it is similar to the original KLEE, with a circuit that still features a 1.6T magnetic flux density and a Helmholtz Resonance dual-cavity design. Of course, everything comes down to the tuning, but it is worth noting that these are not cheap off-the-shelf drivers.