Fosi Audio became famous for their affordable speaker amplifiers, but the company has expanded well beyond that point. One of their latest devices is the Fosi Audio ZH3, which is a combined DAC and headphone amplifier sporting high specifications in both regards. With the latest AKM DAC chip and more than 2.5 W of power on tap, the ZH3 is small but powerful.
Disclaimer: Fosi Audio sent me a unit directly. The ZH3 retails for $199. Additional information on the official product page.
TL;DR: recap
| Pros |
Cons |
| + Compact
+ Original design + Can work as pure DAC + Can work as pure headphone amp + Neutral sound + 2.5 W output! |
– Not really |
Rating: 9/10
Packaging & Accessories
Do not let the simplicity of the cardboard box that contains the Fosi Audio ZH3 fool you: inside there is a full set of accessories. On top of the DAC/amp itself, there are the power supply, a USB-C to USB-C cable (with a built-in adapter to USB-A), an aux cable with 3.5 mm jacks on both sides, a manual, a 3.5 mm to 6.3 mm jack adapter, as well as the remote.
Design & Build
When I removed the ZH3 from the package, I immediately noticed two things: the first is the big orange knob, the second is the unusual shape of the chassis. Rather than having the usual squared shape, the ZH3 has two protrusions on the bottom – or, conversely, a cut or rut – that go through the whole depth of the device, creating a sort of two legs that the device stands on. Under those legs are four rubber feet. This design is certainly unusual and quite unique.
The chassis is made from a single block of aluminium with the front and back attached via screws. The device looks and feels rock-solid. Despite this, its weight is limited to 350 g – though the rubber feet prevent the unit from moving.
Interestingly, Fosi Audio has chosen to make the front of the ZH3 nearly perfectly symmetrical: on the right hand side there is the volume knob, and on the left hand side there is a circular screen of the exact same size. In between the two are a 6.3 mm and a 4.4 jack.
It is very unusual to find circular screens, especially since they have lower area than a square screen with the same width and because they are more difficult to program. But Fosi Audio did an excellent job and managed to cram a lot of information and functionality in it. At a glance, you can see the volume in the centre, the sampling rate on the top left, the input on the top right, the output on the bottom left, and the filter on the bottom right.
The back hosts stereo XLR and RCA outputs, a stereo RCA input, optical, coaxial and USB ports, two 12 V trigger ports (one input and one output) and the power connector.
The volume wheel is a stepped digital actuator which can also be clicked. It spins freely (so there are no minimum and maximum positions), but the ZH3 remembers the volume you set individually for headphone and DAC outputs. It only adjusts the volume based on the actual steps (which you can feel as small bumps when turning the wheel) when you turn it slowly; if you turn it fast, it adjusts the volume faster than the actual turning, which can be useful if you want to adjust the volume quickly despite the loss of precision.
Features & Specs
The Fosi Audio ZH3 supports both single-ended and balanced output as a pure DAC. An interesting thing is that it can operate as a pure headphone amplifier, bypassing the DAC entirely, by using the stereo RCA input. There is only single-ended analogue input, but the balanced headphone output will work anyway.
Most features can be accessed with the included remote or by using the volume wheel. The menu includes various options: input, output, bass and treble adjustments, gain (low, medium, high), USB Audio Class, filter (there are six to choose from), tone control circuit bypass. Two rapid presses will switch between the headphone output and the RCA/XLR output with preamplification (so, the ability to change the volume), which is called “aux”. Using the menu, you can also opt for line out which disables volume control.
The ZH3 works with all the major platforms: Windows, macOS and Linux. The device supports both USB Audio Class 1.0 and 2.0, with the former not requiring drivers on Windows and being compatible with consoles like the Switch and PlayStation 4/5. The compatibility with Linux means that it works in a plug-and-play fashion with the Steam Deck (and, in the future, the Steam Machine).
Fosi Audio ZH3 |
| Input | USB (up to 32 bit / 768 kHz, up to DSD512) Optical/coaxial (up to 32 bit / 192 kHz) RCA |
| Suitable headphones impedance | 16 – 300 Ω |
| Output impedance | “Near 0 Ω” (headphones out) 100 Ω (line out) |
| Maximum output power | 2,570 mW (32 Ω, balanced) 640 mW (32 Ω, single-ended) |
| Frequency response | N/A |
| THD+N (@1 kHz) | < 0.00018% (balanced headphones out) < 0.00024% (single-ended headphones out) |
| SNR | 121 dB (single-ended headphones out) 119 dB (balanced headphones out) |
| Crosstalk | N/A |
The Fosi Audio ZH3 is built around the AKM AK4493SEQ DAC chip, with four Texas Instruments OPA1612 op-amp chips (which you can replace) taking care of amplification.
The ZH3 comes with a remote which not only allows you to control all the features of the device, but it makes it significantly easier to control them as they are neatly laid out on the remote. These include power on and off, screen brightness, mute, volume up and down, navigation keys in the menu (left, right, enter), input, output, filter, auto (to turn the device off automatically after a period of inactivity) and “home” (to bring you back to the main screen, which is useful to exit the menu).
Sound
I’ve tested the Fosi Audio ZH3 using various headphones, including the HiFiMAN HE-560 and Fosi Audio’s own i5 and IM4.
The ZH3 has enough power on tap to drive anything out there, with more than 2.5 W at 32 Ω. Even hard-to-drive headphones like the HE-560 are driven effortlessly: on low gain you need to push the volume to 45 to get to a loud level, whereas on high gain you only need to get to 18 (out of 99), so there is ample room to spare for any headphones.
In terms of sound, I can’t hear the ZH3 having any influence on it when compared to other solid-state DAC/amps like the SMSL C200 Pro. It just sounds dead neutral, whatever headphones or earphones you use. I’ve experimented with the filters, too, but I couldn’t hear a difference between them.
Even with low-impedance IEMs like the IM4, the background is totally silent: there is no hum, hiss or other noise whatsoever.
Final Thoughts
The Fosi Audio ZH3 is their first combined DAC and headphone amplifier, and it is a very strong debut in this market. It offers everything you’d need: powerful headphone output, balanced outputs for both headphones and DAC, good range of connectivity options, neutral sound and a lot of interesting additions like the built-in bass and treble adjustments, as well as the ability to use the device as a headphone amplifier and the 12 V triggers. Add to this a unique and striking design (which still fits everywhere) and you get a super interesting device which is competitively priced as well.
Looking at the wider market, the Fosi Audio ZH3 stands out as a great option if you are on the market for a versatile device which can both be a building block of a new desktop system or an addition to an existing one – as an example, as a headphone amplifier or as a DAC. In any case, the ZH3 is a valid choice that offers great value. Recommended!
