Fosi Audio in recent years has managed to stand out among the countless Chinese companies producing low-cost mini Hi-Fi equipment, becoming one of the best-selling brands in the sector on Amazon. In recent years, the Chinese company has been moving toward higher market segments, developing excellent Class D amplifiers, DACs, headphone amplifiers, and planar magnetic headphones, all characterized by cutting-edge technical parameters and well received by both critics and the public. Prices, moreover, remain very competitive.
After testing in recent months the V3 mono power amplifiers, the ZD3 DAC and the i5 planar magnetic headphone, we now had the opportunity to test the brand-new DAC/headphone amplifier combo from Fosi Audio, the ZH3.
Devices like the ZH3, which combine a DAC and a headphone amplifier in a single unit, have enjoyed great success in recent years among headphone listening enthusiasts, the so-called “head-fi users.” This solution allows for cost reduction and optimization of the design of both the DAC and amplification sections so that they work perfectly together. Footprint is also significantly reduced.
The ZH3 uses the AKM AKM4493SEQ chip for digital-to-analog conversion, one of the most appreciated in this price range. For amplification it employs four OPA1612 operational amplifiers, operating in a balanced configuration. The ZH3 can be used as a DAC + headphone amplifier, as a pure DAC, as a preamplifier, and as a standalone balanced headphone amplifier.
Here are the full technical specifications:
Chipset: XMOS XU316 USB processor + AKM4493SEQ DAC + 4× OPA1612 op-amps
Operating modes: DAC, balanced headphone amplifier, preamplifier
Power supply: external 12 V
Supported headphone impedance: 16 Ω – 300 Ω
Digital inputs: USB, Optical, Coaxial
Analog inputs: Stereo RCA
Headphone outputs: 4.4 mm balanced, 6.35 mm single-ended
Line outputs: RCA & XLR
Supported formats:
USB: PCM up to 32-bit/768 kHz, DSD512
Optical and coaxial: PCM up to 24-bit/192 kHz
4.4 mm balanced headphone output:
Maximum power: 2570 mW × 2 @ 32 Ω (THD+N < 1%)
SNR: ≥ 119 dB
Dynamic Range: ≥ 119 dB
THD: ≤ 0.00018%
Noise Floor: ≤ 4.9 µV
6.35 mm headphone output:
Maximum power: 640 mW × 2 @ 32 Ω (THD+N < 1%)
SNR: ≥ 121 dB
Dynamic Range: ≥ 121 dB
THD: ≤ 0.00024%
Noise Floor: ≤ 1.9 µV
So, truly an excellent set of inputs and outputs and very respectable technical values. Fosi particularly highlights the remarkably low distortion and noise levels:
SINAD ≥ 115dB SNR ≥ 121dB THD+N ≤ 0.00018%
Most modern DACs based on AKM or ESS chips already feature extremely low distortion values; however, the fact that Fosi has managed to reduce them even further compared to competitors certainly testifies to the quality of the ZH3 design.
The Fosi Audio ZH3 is currently sold on Amazon at a price of around €200, placing it firmly in the entry-level range.
Now let’s move on to our test of the Fosi Audio ZH3.
The ZH3 comes in a well-packaged cardboard box. The package includes a rather generic-looking 12V switching power supply, a USB-C to USB-C cable (with an adapter for USB-A on the PC side), the classic 6.35 mm to 3.5 mm adapter for headphones, a remote control (without batteries), and a cable terminated with two mini-jack plugs with “trigger” functionality (allowing simultaneous power on/off of other Fosi Audio devices connected via this cable). The ZH3 is small and has a sturdy appearance. The front panel is designed to match the look of other Fosi Audio “Z” series devices. On the left there is a large round display, on the right the volume knob (which also controls many other settings), and in the center the headphone outputs.
The rear panel is quite crowded due to the numerous connection options. In particular, the presence of an RCA analog input is a welcome surprise at this price point and allows the headphone amplifier to be connected to an external DAC or analog sources such as turntables, cassette players, or tuners. We are less convinced by the use of a USB-C connector for the USB input instead of the more common USB-B. The unit powers on with a short press of the volume knob and turns off with a long press. A short press while the unit is already on accesses configuration settings, which are selected by rotating and clicking the knob. If that sounds inconvenient and unintuitive, we can confirm that it is. The remote control allows quicker access to some functions and is also the only way to adjust certain extra settings such as display brightness.
We tested the ZH3 with numerous planar magnetic headphones (HifiMan Edition XV, HE600, Ananda, Arya, and HE6v2, Fosi Audio i5) and with the Grado SR80E. With default settings, the ZH3 delivers the typical sound of modern DAC/headphone amplifier combos based on AKM or ESS chips designed to minimize distortion and noise: a clean, detailed, and extremely neutral sound, with a clarity that would have been unthinkable for a budget DAC just a few years ago.
The output power is truly remarkable on the balanced output (about 2.5W at 32 ohms), somewhat less on the single-ended output (640 mW at 32 ohms), but considering the price, one really cannot ask for more. There are three gain levels: low, medium, and high. The ZH3 easily handles all the headphones we tested except the HE6v2 SE, which requires an even more powerful amplifier to perform at its best. The synergy with Fosi i5 headphones is excellent, delivering great sound, as is the pairing with Grado headphones. The new HiFiMan Edition XV and HE600 are also driven confidently and produce a full, melodic sound. Less convincing is the pairing with more aggressive HiFiMan headphones in the upper midrange, such as the Ananda or Arya, which in our opinion perform better with warmer-sounding amplifiers like the HiFiMan EF400—though adjustments can be made using the ZH3 filters.
It is possible to use six different filters to tailor the DAC sound to your needs: “Neutral balanced,” “Natural smooth,” “Precise analytical,” “Well defined,” “Extended highs,” and “Powerful dynamic.” The differences are not huge but noticeable and can help refine the sound according to personal taste and the headphones used. For those who want more control, tone controls for bass and treble are available, and for the more adventurous users, there is also the possibility of replacing the op-amps with others featuring different sonic characteristics, as explained on the Fosi Audio website. The sound customization section is therefore far above average for devices in this price range, which are often completely lacking in real-time adjustment options.
It is worth noting that the default “Powerful dynamic” setting delivers an energetic, rock-oriented sound, while switching to “Well defined” allows the ZH3 to perform at its best—at least for certain genres—demonstrating the ability to produce a surprisingly wide soundstage. Instrument separation and positioning are more than good and pair well with the excellent level of detail retrieval for its price range.
Very convenient is the presence of optical and coaxial digital inputs, allowing connection to digital devices such as CD/DVD players or TVs. The RCA input is fantastic, enabling connection to an external DAC, a turntable, or other analog sources.
Overall, we really liked the ZH3. We have only one remark: it is a very small device, even though it is meant to sit on a desk rather than be portable. If it were twice as long, it would still fit easily on a desk and would have allowed enough space on the front panel for all the necessary buttons and switches to ensure convenient access to the main functions of such a complex and versatile device. Yes, we believe that some analog solutions still make a lot of sense!
In conclusion, the ZH3 is a DAC/headphone amplifier combo with truly excellent sound, powerful enough to drive almost any headphone on the market, and above all outstanding in terms of connection versatility and its ability to adapt sound reproduction to personal needs and tastes. We can only wholeheartedly recommend the ZH3 to anyone looking for a DAC with an integrated headphone amplifier in the €200 price range and beyond, especially considering that it performs well even with headphones costing more than twice as much.
Fosi Audio continues to bring highly competitive and intelligently designed devices to market. If you are planning a purchase in this price range, we recommend checking firsthand the excellent value for money of devices like the ZH3.
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