[Listening test] Fosi Audio ZD3 - small and versatile DAC with remote and volume control

Product: Fosi Audio ZD3 - DAC
Manufacturer: Fosi Audio - China
Approx. price: ±€200 (direct sale from official website)
Author: Lucio Cadeddu - TNT-Audio Italy
Published: December, 2024

Foreword

After the great effort made designing integrated amplifiers, preamps and mono power amplifiers, Fosi Audio tries its hand at a very ambitious DAC, which should be the ideal partner of the integrated ZA3 already reviewed here on TNT-Audio. It follows the aesthetics perfectly and the cabinet is exactly the same. The ZD3 is the first “pure” DAC by Fosi, the others in their catalogue are hybrid components which serve as headphone amplifier or integrated amplifier as well, such as the DA2120D, which has also been reviewed (admittedly, not 100% positively) here on TNT-Audio.

The Fosi ZD3 is an ambitious project, developed according to the indications of numerous enthusiasts (for example those on the AudioScienceReview forum) and YouTubers. This is an unusual approach, a sort of crowdfunding of ideas, i.e. a widespread audiophile brainstorming which should, in theory, lead to a product that satisfies the needs of many “experts”. Once upon a time, designers decided how and why to design a certain device which typically followed a sort of brand sound philosophy. With this new approach, in practice, there is no Fosi philosophy, but that of many other thinking heads, put together, it is not clear how and, above all, with what skills or competences. I have already had the opportunity to criticize the fruit of this brainstorming, because it has generated both useless and bad-sounding devices, such as the P3 preamp and the integrated ZA3 (the first is bad-sounding and essentially useless, the second is mostly useless, given that the V3 amp sounds better). Excellent products, however, are the integrated V3 and the V3 Mono power amplifiers. I was therefore curious to find out what this new international brainstorming had generated this time.

A closer look

The ZD3 is a small but very complete DAC: five digital inputs (coaxial, optical, USB, Bluetooth and HDMI ARC) and two line outputs, RCA and balanced XLR. Also available is a trigger in/out connection for the bus connection between different devices. Via coaxial, optical or HDMI the signal that can be managed is 24bit/192kHz, which becomes 32bit/768kHz in PCM, and 512 DSD on the USB input. It does not support HDMI EARC. A switch is available to bypass the volume control. The ESS 9039Q2M DAC is supported by an XMOS XU316, QCC3031 and LME49720. These last operational amps can be replaced to experiment on what type of sound to obtain. Further technical insights can be found in the very detailed Fosi Audio official page.

The (cool) display indicates volume and selected inputs, and has adjustable brightness. The volume range curiously stops at 80, but this is irrelevant, as it is just a number. In fact, at 80 the DAC is already producing the maximum output level (the usual 2.5V on RCA and 5V on XLR). Someone who doesn't understand much might complain that the 100 threshold can't be achieved, as if that means something. If I were an audio designer I would make a volume control that stops at 13, because it's unlucky and it's also a prime number. However, the ZD3 has 80 useful steps, more than enough for any fine level adjustment. From the remote control you can temporarily silence the output, adjust the level and manage the inputs. A 12V and 1.5A power supply completes the package.

Audiophile Brainstorming

It is not easy to find such a complete DAC made with quality components at this price. Chinese companies are unbeatable on this front and are quickly learning both to use excellent components and to create perfectly tidy and clean motherboards and layout. The ZD3 is a prime example of this. From a sound point of view, which is what interests us most, I can say that it does a lot for the money, coming very close to the performance, for example, of the Manunta EVO3.1 reviewed last week. It should be remembered that the latter costs 5 times more. The following notes refer to the operational amplifiers fitted as standard, I have not experimented with other devices, also supplied by Fosi Audio in the packaging.

I would say that tonally it is quite neutral, defined and transparent in the upper midrange, well extended in the lower range, where it gains a few points on the EVO 3.1. It reproduces the first octave with ease and does so while maintaining good control, without however reaching the articulation and speed of the Manunta DAC. A deeper bass range generates the psychoacoustic effect of a slower performance but, psychoacoustics aside, the bass range of the ZD3 gets into trouble slightly reproducing highly energetic rhythmic textures and intricate patterns, with many instruments playing together. At times, you get the feeling the bass follows the rest of the audio range after a very slight time delay. This is an unnoticeable phenomenon unless you make a direct comparison with higher level DACs, of course. So, if listening to the ZD3 alone it seems to you that everything is perfect and in control, know that this is not the case. Without a direct comparison it is easy to miss this phenomenon.

Having clarified this, the key point is that the bass range is remarkable, in terms of extension and power, and if it had a little more rhythm and PRaT it would be excellent, well above what the asking price would suggest. The rest of the audio range performs quite well, without any particular flaws or faults but, as often happens in cheap products, it is the harmonic richness that pays the price. This slight absence of higher harmonics can be heard both on the voices and on the instruments, sometimes devoid of the peculiar character of each of them. So, for example, a cello will sound less rough than it should (and as it does on higher DACs, including the EVO3.1) and the voices will lack some pathos, without those natural connotations that make them more realistic, such as the noise generated by breathing, the parting of the lips and certain dental consonants. Nothing particularly unpleasant, in the sense that there are no particular aberrations or distortions, but a certain feeling of artificial remains, to a certain extent with all musical genres. It does much better, as one might expect, with electrified or electronic music, with which it manages to sound engaging and lively.

Dynamic performance is also good, even if some impulsive noises appear slightly tamed and less punchy than they should be. All this, however, never borders on boredom and annoyance. The three-dimensional image is also not bad for the price, but the sound stage is not as wide and deep as in the Manunta EVO3.1, which better arranges the performers and instruments in the 3-dimensional space. The ZD3 tends to crowd its virtual sound-stage a bit towards the centre between the speakers. This stage, however, appears very stable, prospectively proportionate, albeit on a smaller scale, and all in all quite credible.

Overall, taking into account that the comparisons were carried out with much more expensive competitors, this Fosi ZD3 is almost a miracle. It's possible that the sound varies a bit with other op-amps, but doing tube rolling or op-amp rolling, as is common practice today, is not one of my favourite hobbies. In my opinion, a company must take responsibility for the sound of its devices, not build a gym where crazy audiophiles have fun inserting different Lego bricks (opamps or valves).

Should the volume control not be necessary, because perhaps you connect the DAC to an integrated amp or a preamp, it is better to bypass the potentiometer with the appropriate switch. The sound gains slightly in immediacy and transparency. These are not, however, differences that can be clearly perceived within an entry-level system where the ZD3 will realistically be inserted.

Remarks & Complaints

Manufacturing & finish.
For this amount of money it would be immoral to ask for anything more. The device is nice, well finished, easy to use and works well. The knob for adjusting the output level is a welcomed plus. I don't feel like making any complaints from a manufacturing point of view.
Sound.
There are flaws, but overall it is good, with an excellent bass range and a clear and defined mid-high range. One might ask for for greater harmonic richness in the mid-high range, and superior reproduction fluidity, which would have limited some slight traces of artificiality that peep out especially with acoustic music. The sound-stage should also be wider and deeper.

Conclusions

For €200 it's difficult to ask for more, since this ZD3 doesn't seem out of place when compared to DACs that cost 5 times as much. Need I say more? It doesn't sound better, that's sure, but the differences are small and only perceptible within high-end systems. I invite all those who continue to mock ChiFi devices to be careful, because the quality/price ratio of some Made in China products is becoming embarrassing for the rest of the world. It would be nice to take one of these smart guys, blindfold him, and have him listen to this DAC in a high level system...I think it would be fun. I certainly did not spare any criticism on Fosi Audio during the tests of the ZA3 integrated amplifier and the P3 preamp, but this time I can only conclude with praise for this ZD3, a serious and well-built device, an excellent starting point for entry-level systems with audiophile ambitions.

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