[Listening Test] Fosi Audio ZH3 - Balanced DAC headphone amplifier/preamp

Product: Fosi Audio ZH3 Balanced DAC headphone amplifier/preamp
Manufacturer: Fosi Audio - China
Price: See below
Reviewer: Mark Wheeler - TNT-Audio UK
Reviewed: Winter 2025 - Spring 2026
Published: May, 2026

Pricing is a typical example of YMMV smorgasbord - $199.99 USD (or $US259 to UK), 239.99 €, on their own website and there are various AliExcess and Fleabay offers, which may or may not be the genuine article. Currency and market volatility is the order of the day in these uncertain times. If you can find a local physical store, do pass some real cash over their counter to keep your local economy alive.

What is it?

A few years ago this would have been unique. A paperback book sized box containing a DAC with a fully balanced preamplifier plus headphone amplifier with only one analogue input. Admittedly the analogue input is also configurable too. Digital input options include USB, optical, and coax.

The DAC is no slouch, being the AKM AK4493SEQ which paired with the XMOS XU316 USB interface can support 768kHz bitrate PCM (Pulse Code Modulation – the music choice standard of encoding) at 32-bit depth which would have been only a pipe dream in the days of CD and DAT.

Sweeten the deal with a fully balanced analogue amplifier section (OPA1612 op amps) sufficiently juiced for 2.5Wpc (32Ω) and this is an ideal desktop metal box. Ideal desktop because the noise rejection and screening of such a thing will be highly tolerant of the electrically noisy environment of PC/MAC and numerous peripherals like game controllers. It'd look cute there too with its trademark Fosi big orange knob (fnarr fnarr) and tidy circular display screen. But that is not what we do here at TNT-Audio; here we subject equipment to audiophile and studio standards.

Fosi have such confidence in their products that they're willing to subject them all to TNT-Audio's unbiased scrutiny. This little baby (and it is a little baby) arrived well before the product launch. It offers so many permutations and combinations of inputs, outputs, configurations, DAC filter types, yadda yadda. The Fosi is sold as an all-in-one desktop solution but I am reviewing the ZH3 in 3 ways because they are the 4 obvious applications that I see:

As well as bass and treble EQ adjustments there are 6 filter types. All the functions are integrated into the tiny screen “for a clean, premium look that continues the Z-Series design language” but that actually irritates 7 colours of poo out of your Old Scribe. I detest menus by an exponential function: that is if having a menu is twice as irritating as having proper switches, a menu with submenus is 4 times as irritating, a third level of menu (submenus in submenus) is 8 times as irritating, ad infinitum. Actually the first menu irritation quotient probably equals Irritation⁴ from the get go.

I nearly deafened myself first time I connected this wee beastie. Several other online commentators have complained that the default volume is set to 99, aka maximum. That amounts to 4V of energy straight into your power amplifiers. No thanks! Making this mistake just once might cost your tweeters or your eardrums.

For an equally modest outlay Fosi can supply a pair of 200W power amplifiers. That is your bass section of a multi amped system and their 100W monoblocks will do for treble and midrange.

There are so many possibilities and options that this test is very time consuming. We are unpaid at tnt-audio.com so this has to fit around our day jobs and family commitments. The enclosed 'full remote control' is plasticky compared to the lovely aluminium unit itself but actually no worse than that of a €$£10k ARC pre-amp! The RCA connections are as good as they can be. RCA connections are always horribly inferior to the XLR connections, obviously, not just your Old Scribe's prejudice, but proper engineering would never make the live connection before the earth/ground. The Fosi ZH3 was launched just in time for Winter Solstice and it has been in irregular use since then.

Testing Beyond the Edge

Here at TNT-Audio we take it to the edge then we push a little more. So your Old Scribe tests the Fosi ZH3 against the internal DAC (Chevron modified) Shanling valve and the tube-rolled Audio Research Corporation Reference 3 line level pre-amplifier...

Plebs “Whaaaat!?!?” Yell incredulous Plebs, stage left, “The Old Scribe is testing a €250 combined DAC/pre-amp against €15,000 worth of modified gear?”

Why not? The point is to establish if it is good enough to enjoy music through because this is a subjectively driven music lover's audio review webzine. The Fosi ZH3 will be driving your Old Scribe's optimised Euterpe active system. The latter is like riding a custom motorcycle; there may be better performing motorcycles out there but when you optimise something for you, the sensory experience is on another level. I leave the little Fosi plugged in on standby, occasionally switching off and on again to cycle the innards. There are folk who are sceptical about this but they've obviously never measured a bunch of fresh capacitors and remeasured them after a few charge-discharge cycles.

“That's two controversial statements in one paragraph,” note observant Plebs, stage left, “Where is this all heading?”

Your Old Scribe gets testing and decides to throw caution to the winds and begin by connecting directly between the digital output of the modified Shanling CDT100C and the input of the Marchand fully balanced all valve active crossover. At first this involves some ordinary RCA terminated coax between the transport and the Fosi. This will be substituted later with various alternatives. Fosi to Marchand is 5m xlr terminated Black Rhodium Concerto. This too will be substituted later for 5m Van Damme Star Quad. Whether the RCA-RCA cables are supposedly low jitter types is unknown. It's just from the drawer full of wires we all have.

Fosi claim high output power on the headphone socket (640mW@32Ω x2) and I wonder if the XLR connections also deliver high current with a low source impedance, judging by the claim “Equipped with both 6.35mm single-ended and 4.4mm balanced (2570mW@32Ω x2) outputs”. There was no change in frequency response with the output cable substitutions. That output power is not far short of a 2A3 so you could try this directly connected to a big horn system for real audio insanity.

Let us just think about that again: a pre-amp/DAC the size of a modest novel delivering the output of a small Single Ended Triode power amp. That speaker sensitivity, or our connected active system, will be horrible if the noise is high but Fosi claim that their self-developed dual-power balanced amp circuit with multiple ultra-low-noise LDOs and capacitors keeps noise as low as 1.9μV. They also make a big deal of their chipset while offering the option of chip-rolling: possibly substituting for that chipset of AKM4493SEQ DAC, XMOS XU316 processor, and four OPA1612 amps. So you could customise the Fosi with various easily replaceable DIP8 dual-channel op amps. Compatible chips include the LME49720, NE5532, MUSES02, SS3602 and there are apparently detailed video tutorials available. An audiophile's dream of time consuming activities.

Initial Sound Quality

With so much customisation available your Old Scribe started in full bypass mode and automatic selection of bitrate and filters. With no attempt at optimisation this little device sounds scarily close to the Shanling/ARC combination. Really.

First CD played is Courtney Pine: Europa. The Fosi Audio ZH3 acquits itself well. I soon forget that I am reviewing and enjoy music that I first heard live somewhere or other on the Europa tour. There is something about the orchestration that reminds me of Duke Ellington, other times there are crazy time signatures [see what I did there and the plebs missed it!], then it's a Klezmer feel, then it's far out man.

Sly and Robbie's Strip to the Bone is up next. With 44kHz sampling, compared with the references, bass depth and articulation are only slightly below par through the Fosi than a five figure front end. With that 44kHz sampling rate the rest of the audio spectrum is exactly as expected from top quality Red Book CD playback. For a composition partially built from samples by Howie B, the soundstage and individual instrument positioning are well constructed. In a system where each of the midrange power amplifier Western Electric valves exceeds the price of this combined DAC/pre-amplifier, the Fosi ZH3 is far less of a bottleneck than many much more expensive pre-amps that have passed through the system.

In this high-end company, bass quality is only slightly compromised as is soundstage. The former is probably down to the power supply and the latter could be the less than optimal connection to the transport output. Alternative bits of wire were then tried between CD transport and Dac, which made only a little difference. Continued optimisation and playing with settings enabled various conclusions to be drawn. From the get go, the Fosi ZH3 is seriously punching well above its price weight. Bits of wire and different plug brands in the digital connection make no significant difference. The input buffer is doing its job.

The only sound quality compromises are at the frequency extremes and then only in terms of a high end system. With the standard Fosi power supply the bass slam and extension are significantly compromised compared with the best, but low frequency pitch remains intact. Compared with anything under £€$1000 most other DAC's and pre-amps will be similarly compromised at one, other or both ends of the frequency bandwidth. The addition of a big linear power supply in place of the supplied unit would probably solve this. &euro109 buys the substantial Fosi Audio PS-48V-10A power supply for your podcast mics. Fosi would do well to offer an aesthetically matched big brute of a power supply for the Fosi ZH3; the easiest sales are to existing customers and such a device would put the Fosi ZH3 in a much higher league competing with traditional HiFi brands in the €£$2k plus market. Despite this criticism the rhythm and timing survive intact. Both Courtney Pine's Europa and the late Sly Dunbar's percussion are tough tests of timing.

Filter Swapping

Your Old Scribe first encountered the thrills of playing with bitrates, slopes and filters with the $4k Zero One system (no relation to numerous Chi-Fi products similarly branded). The Fosi Audio ZH3 allows users various filter options. Whether your own belief system about such things is to shape the sound you hear to fit your need (like tone controls) or to better match the source data, the options are there. Swapping the RCA-RCA digital connection for a different unscreened wire has no audible effect. Arguments about digital cables will not be entered into and the Plebs Chorus are noticeably quiet. The Shanling CDT100C features a quad Burr-Brown PCM 1704 DACs, PMD-200 HDCD filter and CS8420 sample rate converter which might technologically be considered ancestors to the Fosi chip line-up. There might be a comforting familiarity.

Soundstage is the most affected playback parameter, as we might expect from tinkering with high frequency phase. The Fosi ZH3 user manual uses words like, 'powerful', 'detailed', 'dynamic', 'precise', 'smooth' to describe the filter effects. Apart from what sounded like some ringing on the 'Low Dispersion' setting, there were few obvious differences in the frequency domain. The 'Natural Smooth' and 'Well Defined' settings offered the deepest widest soundstage. Either of these also seemed to have the least time domain effects on leading edges too. There is so little difference on most recordings that I doubt anyone could differentiate these two settings from the default 'Neutral Balanced' setting, defined as a 'slow roll-off filter'. After playing around with various settings, your Old Scribe mostly left it on automatic, which means whatever was last or 'Neutral Balanced' if it has been disconnected from the power supply for a while. When used as a DAC only into the ARC Reference 3 the filter preference switches to Extended Highs; once again context is everything.

Speaking of power supply, the one glitch relates to this. When in standby mode, if the power supply is momentarily or temporarily interrupted for whatever reason, the Fosi ZH3 turns itself on. The Old Scribe lives in an old house, in a town on a peninsula and often has momentary supply interruptions when the lights will momentarily flicker and the Fosi ZH3 will wake up, indicated by the display lighting up.

As Headphone Amplifier

Your Old Scribe is no great fan of extended headphone listening under any circumstances. There is something about the whole back of head location thing, primarily a function of the human ear pinnae being bypassed, that undermines the pleasure of complex and exciting music. I used my own familiar Sennheiser HD280 Pro sealed back circumaural headphones from their current range. The headphone results from the Fosi ZH3 are absolutely consistent with those through crossover, power amps and loudspeakers. A big soundstage, treble that succeeds simultaneously in being clear, and phase coherent, without being fatiguing, natural midrange and well articulated bass are achieved to the extent that a desktop headphone set-up needs nothing more than a source, a pair of cans and the Fosi ZH3.

Your Old Scribe hooked up a Soundcraft #### balanced mixer and compared the mixer's own headphone socket with the Fosi ZH3 fed from the mixer XLR outputs. The Fosi is a great little headphone amp with a lot more wellie than the inbuilt mixer headphone output. There was no noticeable extra noise from those extra connections, nor did the Fosi inject any extra noise on the mains.. We can infer from this that the Fosi ZH3 might find a use in a podcast set-up too.

Sound Quality: Slight Return

The first two albums played from the Shanling's RCA digital output into the Fosi ZH3 were spectacular when we consider that there is more money sunk in the connectors (not the wires, just the 12 Neutrik XLR plugs and sockets plus 4 RCA plugs and sockets) in a multi box 3-way active system than this source component. I completely forgot that this DAC and pre-amp were in the system and erroneously grabbed the Audio Research Corporation remote control to mute the volume when someone arrived.

Brutally, the third CD into the transport was Pictures at an Exhibition, not the Mussorgsky orchestration, nor Emerson Lake & Palmer's arrangement, but the splendid Tim Kliphuis Trio take on this very modern 1874 composition. Your Old Scribe had been at this trio's performance of this piece the previous night in Wigtown County Buildings promoted by the Newton Stewart & District Music Club. It is amazing that this international trio are willing to schlep out to the sparsely populated bottom corner of Scotland. They did and what a great night it was. Despite the acoustics of the high ceiling cuboid space, without stage ceiling reflector and almost devoid of curtains, the performance was clear and balanced. Being a pukka jazz outfit every performance is different and this one had its out there moments in the best sense of the phrase. At various times in the evening they seem influenced by everyone from Django Reinhardt and Stéphan Grappeli, who obviously spring to mind, but the Hokusai inspired The Great Wave also conjures Steve Reich, John Cale, John Cage and Le Monte Young. They try to raise awareness of climate change somewhat less overtly than Orbital too. Do go and see them.

Enjoyable enough indeed, to buy three CD's of their albums and one of the only album they had on vinyl. Pictures at an Exhibition is the album they're currently touring. It's more a case of 'Inspired' by Mussorgsky's 'Pictures at an Exhibition', constructing fresh arrangements from its themes and motifs for 7 tracks as well as extending the exhibition to include Georgia O'Keefe (a favourite from Old Scribe art skool days), Van Gogh (correctly pronounced by Tim Kliphius, a native of Holland), Hokusai and Gustav Klimt. Recorded in 2024 the production is sufficiently well balanced that there were no nasty surprises next day playing it through the Fosi ZH3. The level is low enough to allow proper dynamic range rather that loudness war limiter crashing and the gatefold cardboard sleeve (infinitely superior to the cassette derived horrible jewel cases) with pull-out notes. So enjoyable was the performance and recording that it got an immediate second play through while your Old Scribe checked the previous findings of the filter settings. Bostin, as they say in the English Black Country.

Trying to follow the Tim Kliphuis Trio would be a challenge. The excellent sampler Jazz Grooves: Best of Mapleshade Volume 3 produced by Pierre Spray sprang to mind and your Old Scribe even knew where to find it! Famously excellent for succeeding in the almost impossible task (theoretically) for getting the highest frequency timing right on Red Book CD standard, the Extended Highs filter sounded smoother than Natural Very Smooth setting; go figure. Drum sounds had a consistent transient and decay and the big soundstage also implies good filter phase performance. The opening baritone sax on the Hamiet Bluiett Sextet's Sir Phyllis Blues has that 'in the room quality' we seek from domestic audio playback with the accompanying piano somewhat distantly behind the house wall. Pretentious? Moi?

Conclusion

I do not know how it is possible for the Fosi ZH3 to be this good at this price. Given that its architecture allows for fine tuning, for chip rolling and other tweaks, it is extraordinary. Both the balanced XLR line out and the headphone amplifier are good enough for most purposes short of the higher echelons of audio.

Adding a big linear power supply might well elevate the sound quality of either the DAC or pre-amplifier sections even further. The law of diminishing returns means that a much bigger budget is needed to better the little Fosi ZH3 DAC pre-amplifier for those who can cope with just one digital input and one analogue input. Your Old Scribe suspects that it is this simplicity that has made this little gem possible.

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Fosi Audio ZH3

Great things in small packages