Fosi Audio ZD3

Thank you all for your reviews.

As a long time audiophile (in the proper sense) and used to more expensive DACs (I've also done lots of mods on DACs and especially R2R DACs) I would like to add some remarks. IMO the Fosi ZD3 and the Fiio K11 R2R are currently the most interesting low budget DACs from the two camps: R2R vs sigma delta. In my experience there are some fundamental differences. And a discrete R2R is more expensive to make due to the need for low tolerances in the resistor ladder. A SD dac just takes the latest and greatest dac chip and builds around there with proper power supply and output stage. It's not just the dac chip that defines the sound.

Now I have not heard either the Fioo nor the Fosi. But I do have similar DACs. And what MatAudiophiles wrote comes very close to what I learned over time. R2R sounds more natural with more emphasis on tone and timbre and detail seems a bit lacking. Soundstage van be more narrow but with good depth and a sense of space, you can almost hear where the walls of the venue are (as long as it's not a multi track studio recording or electronic music). Details are all there but more like in real life, a bit subdued it seems.
With sigma delta, like the Ess 9038/9 you get a wider soundstage and details 'with sprinkles on top'. Depth depends a lot on the quality of the output stage.

Now what do I mean with subdued or sprinkles on top? This has to do with timing issues that derive from the architecture. A non oversampling (NOS) R2R dac has more correct timing in the sense that it only has some post ringing. This is fully natural to our ears and brain. If you hit a bell, it rings, as does a string or the wood body of a guitar.
Now the thing with oversampling sigma delta DACs is, that it also has pre-ringing, which is very unnatural. Like the bell already starts ringing in anticipation of getting hit. Or the water surface of a pond starting to ripple before the stone hits. That's disturbing, like in the movies 'Minority Report' or 'Tenet'. Time flowing backward.

The dac chip in the ZD3 is the ESS q2m version of the newest 9039. That means: more effort has gone in to minimizing that pre-ringing. Less 'magic fairy dust' treble detail. DACs are still getting better. The q2m version means it's cheaper and less power consuming, meant for mobile devices. It only has 2 channels where the full pro chip has 8 channels. Other than that it's completely the same. There are DACs and streamers with this chip costing thousands of dollars.

The good thing about this Fosi ZD3 is that you can upgrade it to a much higher level by upgrading the very important output stage. And even to a silent linear 12V power supply if you want.
The connections are very sensible, besides SP-Dif coax and optical, the standard USB-b for which there are plenty of upgrade cables. The HDMI input is not for the audiophile i²s connection unfortunately (bypassing the SP-Dif or XMOS usb input chips) but in this case the more appropriate HDMI-ARC for connecting your TV. ARC means audio return channel, usually for soundbars, so you can change the volume of the dac from your tv remote.


Now to the opamps. This decides close to half the sound quality of the entire dac! Yes, it's that important. PS, input signal processing, DAC chip, output stage... They all matter. Here you can choose what kind of output stage you want. The supplied opamp IC's are just a start. The real business is discrete opamps like Burson, Sparkos, Akliam, Audience, OracleII 02 or several other Chinese suppliers. Costing from $15 to $90 a piece. The OracleII 02 only cost $7 even, and has a nice smooth warm sound. It's really an upgrade over standard NE5532 opamps. My favorites are the $16 Audience SX52B (the brand is almost never mentioned) and the $45 simply named 8802 discrete dual opamp (that is an OEM of that brand that is the current hot topic). Just look on AliExpress.
There are 3 opamps inside. 1 for the RCA output and two for XLR. So if you want you can make do with just 1 opamp on the RCA. Or just 2 if you want to go all out with XLR. You don't need 3. Just watch the orientation; pin 1 on pin 1, dimple on dimple.

One last thing: this dac has the same size as the Fosi ZA3 amps and is meant as a companion. I have a pair of Fosi ZA3's with the 8802 opamps and they are really stellar performers, on par with my >$4k class AB and 300b tube amps. I doubt the ZD3 can play in that league even with Sparkos opamps. But with upgraded discrete opamps I expect you will need to spend 5x as much to get a substantial upgrade, IF you have the rest of your system on that level.

I tried posting a comment but that's too limited for what I had to share. Often Chinese products in this price range are underestimated which means there's not enough info on its potential for audiophiles that can handle a screwdriver.


My rating is absolute, not relative to price. And based on upgraded opamps. Hoping to have a sample soon.

Intro

This is an another innovative product from Fosi Audio called ZD3 a Preamp Dac that offers versatile connectivity and impressive sound performance what your gear you pair with it. The addition of HDMI Arc I find it unique where you can connect your television at ease for immersive listening.





Disclaimer

I would like to thank Fosi Audio for arranging ZD3 for evaluations. My opinions are unbiased, and I haven't been influenced or instructed to praise these gear. Every detail in this review is actual experience made by listening for hours everyday.


Specifications

ChipSet : XMOS XU316 + ESS 9X039Q2M + QCC3031 + LME49720
Maximum Sampling Rate :
USB : PCM 32bit/768kHz; DSD512
OPT/COAX : PCM 24bit/192kHz
Bluetooth : PCM 24bit/48kHz
Output Level :
XLR : 5Vrms RCA: 2.5Vrms
Input Mode : USB, HDMI (ARC), Coaxial, Optical, Bluetooth
Output Mode : XLR, RCA
SINAD : 126dB
THD : ≥120dB
THD+N : <0.00008%
Dynamic Range : ≥123dB
Noise Floor : ≤2μV
Bluetooth Version : 5.0
Bluetooth Connection Distance : ≥13m
Bluetooth Transmission Audio Format : aptX HD, aptX, AAC, SBC
Power Supply : DC 12V 1.5A
USB Compatible Devices : Windows 7, 8, 8.1, 10, 11





Packaging

Fosi Audio ZD3 Preamp DAC
Power cable
USB tybe B cable
3.5mm to 3.5mm Cable
Remote control
Manual guide


Build and features

The body is made from metal, it looks sturdy imo, whenever I using this preamp dac the Oled screen is very helpful determining what mode are you using and the number in the middle is volume level of your output.

Take note :
The ZD3 has a switch at the bottom of the body. It can go bypass mode to become a pure dac and the volume is locked at this time.

The volume knob functions as a control to the preamp dac (if your not using the remote), pushing the volume knob once switching the modes of the ZD3 (USB, HDMI (ARC), Coaxial, Optical, Bluetooth)
And long pressing the knob will turn off or on the ZD3.

At the back panel you will see all the available inputs in the ZD3. I have one this thing will improve is putting a USB type C input because most of portable device now is using this type of USB. The addition of HDMI Arc is impressive making this preamp dac can be use in your television making your movie watching immersive.





Sound Aspects

The Fosi ZD3 sounds neutral, full and a little warmth, I paired this with my Boaleco PX2 a very transparent tube amp and the added warmth to the amp makes presentation musical and engaging at the same time. A lot of micro details you will find it here in my experience.


Source used :

IQOO Neo9s pro
Boaleco PX2 Tube Amp
CVJ Aria Qimeng
KiwiEars Singolo

The Fosi ZD3 spend 20-30 hours of burn in before taking details of this review


Note :

The ZD3 does not have USB type C to connect to my phone and ddhifi has the solution. Im using DDhifi TC01B type C to Type B Adapter to access the ZD3 in bit perfect mode.


Pairing with CVJ Aria Qimeng

This Aria is a super vivid sounding iem due its bright sound signature. The bass is punchier and now produces long satisfying rumbles. The mids is vivid and clearer and well bodied. The vocals has more frontal approach I find it offensive in higher volume. The treble is tamed down a bit without compromising the extension makes the Aria pleasant to ears. Speaking of technicalities, this is my favorite improvement in the Aria. it has airy and spherical soundstage without sounding boxy and exceptional imaging and layering can be attained using the ZD3. The added warmth of ZD3 on the Aria makes the presentation a balance of technicality and musicality.


Pairing with KiwiEars Singolo

The warm-neutral sound signature of Singolo pairs well with ZD3 even though both are warm tilt gears. Surprisingly the singolo improved instead of become outright warm. The bass is cleaner, airy and well separated to the other instruments. The mids is fuller, clearer and lusher. We will hear well textured vocals with the help of ZD3. The treble is airier and well extended as well as it add bite on the attack which became far from boring sounding. Another iem have significant improvedment on the technicalities. The soundstage is wider, taller and have accurate placement of instruments. The improvement of separations of instrument is noticeable with this pairing. It picking up more micro details and nuances with this pairing.





Conclusion

In general, I find the ZD3 is very versatile in other iems, pairing it with everything you have no problem synergizing it. Warm or bright gears is accomodated by ZD3, it makes the sound fuller and livelier which adds to the musicality of the presentation. The addition of Oled screen informs the user what connection is being used which makes the ZD3 very impressive.


Non affiliated link below :
https://fosiaudio.com/pages/fosi-au...FEOUgGU-aG8bgxXi-ufe7j3vn-4i69OZVDExsGhm7Ya3m

MatAudiophiles
When music flows in your veins, choose a good guide!

Fosi Audio ZD3​

Fosi Audio ZD3
INSTAGRAM: LINK
YouTube: LINK

Prelude:
Audio manufacturers rarely openly cooperate with consumers. Fortunately, Fosi Audio in its pursuit of perfection went a step further by openly asking what audiophiles from around the world need. And so, after many months of designing and working on its latest creation, Fosi Audio showed the world its latest digital-to-analog converter with a fully balanced circuit. It is worth noting here that the Fosi Audio ZD3 can boast not only a huge number of functions, but also an extremely attractive price of only 219 USD (on the manufacturer’s official website) as of the date of writing this review. I would like to emphasize that the Fosi Audio ZD3 brings many innovations and a lot of design improvements in relation to the price we will have to pay for it.

Technical data:

Unboxing and ergonomics:
As you can guess from the attached specification, this is a strong contender, despite its low price and relatively small size, the Fosi Audio ZD3 offers a lot of interesting solutions, but before I move on to describing the functions themselves, I would like to invite you to my YouTube channel where I published an unboxing of the Fosi Audio ZD3. The device itself is received in a large cardboard box with a print. After opening the box, we can see black protective styrofoam, the device itself in protective foil, a card with instructions and accessories. The accessories in my case included a remote control, an antenna, a switching power supply, unfortunately without the possibility of replacing the tips with standards other than European. Additionally, a USB C-B cable, a trigger cable (AUX) and three JRC 4580D operational amplifiers. There are no replaceable operational amplifiers as standard and they must be purchased separately. As you may have already guessed, a huge advantage of the Fosi Audio ZD3 is the possibility of replacing the operational amplifiers with other popular models yourself, but this is a complicated procedure and requires familiarization with the manufacturer’s instructions. The device itself is a medium-sized block with slightly rounded ends. On the front, we have a potentiometer that also acts as a function button and an OLED display that informs us about the operating mode and volume of the device. On the bottom, we find a preamplifier or fixed output level switch. While I am glad that such a switch exists, its location is simply inconvenient and I would prefer to place it on the front or side of the device. However, I understand that for design reasons, this location was decided and not another. On the back of the device, there are XLR outputs, RCA outputs, as well as a trigger output and input, HDMI input, Coaxial, optical and a 12V/1.5A power supply socket. We also have a Bluetooth antenna, but when using this mode, we are limited to APTX HD. This is an additional function, and every Bluetooth is lossy, so I do not consider it a disadvantage. We will also find a USB input, but not in the USB C standard, fortunately, we will find the appropriate cable in the set. To replace our operational amplifiers in the Fosi Audio ZD3 we need to disassemble our device and purchase three pieces of the appropriate amplifier.



Sound:

I will use the non-preamplifier mode for my description, and in the next paragraph I will describe what changes occur in the preamplifier mode. During the tests, the Fosi Audio ZD3 was connected via RCA sockets to the amplifiers: EarMen Ch-AMP, ST-AMP and due to the lack of a 4.4mm output, which I personally regret, I used the XLR connection and connected the Fosi Audio ZD3 to the HifiMan EF600 to test all the possibilities of the Fosi Audio ZD3. I will present my impressions in a pair with the HifiMan arya organic headphones and dekoni pads, and the HifiMan HE1000se, as well as the reference OlloAudio X5s headphones. The music comes from high-resolution streaming.

Low tones:
First of all, I noticed the huge dynamics, and the bass was shown quickly. Various textures and depth were perfectly transferred by the Fosi Audio ZD3. It is worth emphasizing here that this is a relatively neutral DAC and faithful to the original presentation, but its sound has been warmed up so as not to overwhelm the listener with excessive severity in the presentation. The offered low-frequency tuning is the kind of bass that makes “your foot fly to the rhythm of the music”. It is amazing how plastic the sound of the Fosi Audio ZD3 is. Low tones depend largely on the recording itself, because the Fosi Audio ZD3 is a fairly honest DAC and accurately shows all the nuances of the recording, but it does it delicately enough not to overwhelm the listener. Low tones are elastic and clearly emphasize their presence, but do not interfere with the other bands, which makes the sound really engaging and pleasant. I also did not have the impression that the sound was excessively thin or contoured, instead I received maximum listening pleasure.

Midtones:
In general, the sound of the midrange offered by the Fosi Audio ZD3 is extremely musical, but at the same time shows a lot of details and technical layers. This is not the typical boring neutral sound. This bit of warmth and analog magic in the presentation allows you to focus on the music and literally enchants. The resolution of the midrange is very high, and the ability to recover details and show details is also at a very good level. When it comes to the soundstage, it is great, especially in terms of width and modeling of sound on the 3D plane. Instruments are placed in their places, planes are shown in accordance with how they were recorded. At times, the presentation was really charming, and vocals could literally enchant with beautiful and emotional texture. However, this did not happen at the expense of clarity or readability, so the final presentation always came out not only clean, but above all tried very hard to engage the listener in integration with the music. Personally, I am glad that Fosi Audio in the ZD3 model went towards the pleasure of listening, and not at all costs towards colorless neutrality. However, despite such tuning, the Fosi Audio ZD3 still adds relatively little to the character and sound of our amplifier, which is an additional strong asset.

High tones:
This area in the case of the Fosi Audio ZD3 is very extensive, we have a huge amount of air and purity in the sound. All instruments have the right extension. Despite the use of the Sabre transducer, the upper frequencies are not sharp or unpleasant. They have excellent texture and do not lack resolution. In both instrumental and popular music, we can notice a lively and engaging sound without feeling tired with excess information. Here I would like to point out that the Fosi Audio ZD3 is very good at reproducing details, but in my opinion it does not sound too clinical. On the contrary, the sound offered by the Fosi Audio ZD3 made it difficult for me to break away from the music. The sound, despite its detailed and musical tuning, is not overwhelming or overstimulating our minds for a moment. Everything is simply in its place, offering the right dose of emotion and tuning that is clean and properly balanced.

Sound in pre-amplifier mode:
The basic change that can be noticed almost immediately is greater control over the volume, because the basic power level in the non-preamp mode in the case of the Fosi Audio ZD3 is quite high. However, this is an obvious change, resulting from the volume control that we gain in the pre-amplifier mode. Additionally, the sound undergoes a significant change, it becomes less neutral, and instead we can observe more warmth in our music. I would not call this sound a typical analog “teddy bear”, it is rather still a very strong technical proposition with very clean tuning. However, the sound becomes softer, more plastic and engaging for the listener.
Replacing the operational amplifiers with JRC 4580D:
First of all, I would like to note that the warning on the Fosi Audio ZD3 housing about the possibility of damaging our device with an unskilled attempt to replace the amplifiers is completely justified and I really recommend caution. However, if you already have minimal experience with electronics, you can safely unscrew these few screws and look inside. In standard Fosi Audio ZD3 sets, there are no replaceable amplifiers in the set, but you can easily buy and replace them thanks to the factory-installed stands inside the device. As I mentioned, my set included additional JRC 4580D amplifiers, for our replacement we need exactly three pieces of such operational amplifiers. After replacing the amplifiers, my sound became less analog and less warm, instead even more information and details appeared. The sound became more balanced and clearer. However, despite the greater clinicalness in the sound, the tuning did not become harsh or unpleasant, and the whole still retained a pleasant, but slightly more resolved character.

Comparisons:

Fosi Audio ZD3 (219USD) VS Earmen Tradutto (599USD)
It is worth noting that there is a large price gap between these two digital-to-analog converters, but they are based on similar components, so I decided it was worth comparing them. In my opinion, the Fosi Audio ZD3 offers a slightly more neutral sound and a slightly smaller amount of detail. Thanks to the possibility of tuning with replaceable operational amplifiers, the Fosi Audio ZD3 is also very flexible and it is easy to tune its sound to our individual expectations. However, it should be remembered that the difference in price that we will have to pay for the Earmen Tradutto is fully justified, because listen, that the Earmen Tradutto is simply a slightly higher class converter with greater resolution and more detailed sound. Let us understand each other well, both converters are excellent and play in a very engaging and natural way. If you want to spend less, feel free to buy the Fosi Audio ZD3, it is a very good converter and offers excellent sound. If you still want to go a step further, then EarMen’s Tradutto is a great development of the sound offered by Fosi Audio ZD3.

For whom Fosi Audio ZD3:

• For people who like to mod their equipment
• For people with a smaller budget
• For people looking for a greater variety of inputs and XLR outputs.
  For whom EarMen Tradutto:
• For whom EarMen Tradutto
• For people looking for a small device size.
• For people who want to go a step further in sound.
• For people who prefer a 4.4mm connection instead of XLR.

Fosi Audio ZD3 (219USD) VS FiiO K11R2R line out mode only (169USD)

This comparison is quite difficult, because FiiO K11R2R is a wonderful and very analog DAC on the R2R architecture. Its sound is warm and full of emotions. At the same time, the presentation is not overly large. The instruments are shown in a more intimate way, which additionally increases the emotional character of the tuning itself. At the same time, the Fosi Audio ZD3 is more technical, separates instruments more strongly and offers a much more resolved sound. Despite the fact that the Fosi Audio ZD3 is full of natural warmth, it does not sound as analog as the R2R architecture of the FiiO K11R2R. Therefore, which device will be better depends only and exclusively on our individual preferences. Both devices are great in their categories and I would have to be very unfair if I criticized them for what they offer.
For whom the Fosi Audio ZD3:

• For lovers of a larger sound stage
• For people looking for a technical presentation
• For lovers of device modifications
  For whom the FiiO K11R2R:
• For people looking for analog sound
• For people looking for an all-in-one device.
• For people looking for a small device

Fosi Audio ZD3 (219USD) VS xDuoo MU601 (149USD)
When it comes to this comparison, it is not easy, the xDuoo MU601 is a small basic DAC dedicated to stationary devices. Thanks to its great implementation, it offers excellent and exciting tuning with a very clean and dense sound with a truly analogue tuning structure. Fosi Audio ZD3 offers more in terms of connectivity and is balanced, additionally sounds more resolved and has a stronger technical layer. Personally, I love my xDuoo MU601 for its reliability and smooth analogue presentation. At the same time, I love the technical layer offered by Fosi Audio ZD3. That is why I consider both devices to be extremely valuable. However, if you want a balanced DAC, head towards Fosi Audio ZD3 and add a few dollars more.
For whom Fosi Audio ZD3:

• For people looking for a balanced connection
• For people looking for more dynamics and resolution
• For people who appreciate the presence of Bluetooth.
• For whom xDuoo MU601:
• For people looking for even more analogue tuning
• For people looking for a smaller device
• For lovers of classical music

Summary:
To be honest, the Fosi Audio ZD3 is a really impressive device, it has almost everything you could wish for to be happy. It also offers the possibility of adjusting the sound to your own preferences using replaceable operational amplifiers. Unfortunately, replacing them is complicated and I would gladly see a mounting flap in the next version. We have a lot of inputs at our disposal, although I missed the 4.4mm output, but this is just my whim. The build quality of the Fosi Audio ZD3 is really great, and each element fits together perfectly. Fosi Audio was not joking when writing that the ZD3 is an exceptional DAC/PRE model. The sound offered by this digital-to-analog converter is full, clear and maximally engaging. All this means that we can easily fall in love with the Fosi Audio ZD3. Of course, if someone is looking for a higher-class sound, they can reach for other more expensive solutions on the market. However, to be honest, it will not be easy to find something with a similar quality to price ratio for 300/400 USD. In terms of Bluetooth, I missed LDAC support, but it is an optional extra, not the main use for the Fosi Audio ZD3. That is why I consider the Fosi Audio ZD3 a great device offering excellent value for money. It is clear from all this that Fosi Audio listens to people very carefully and this is an additional argument to support such manufacturers.

Why choose the Fosi Audio DZ3:

• Excellent sound
• Perfect workmanship
• A large number of inputs and outputs
• High versatility
• Good accessories included
• Interchangeable operational amplifiers

• What I would improve in the Fosi Audio DZ3:
• I would add LDAC and a 4.4 bal output
• I would like a slightly smaller housing

Disclaimer​

Hello everyone! I want to start by saying that Fosi Audio sent me the ZD3 for this review. That said, I must make it clear that everything I have shared here is based only on my experience with the product. Fosi Audio hasn’t influenced what I write or when I publish this, so I have the freedom to express my true thoughts, and my opinion haven't change because of this.

I want to thank Fosi Audio for this chance, and thank you to you, the reader, for trusting me and taking the time to check out my review!

Introduction​

So let's introduce the ZD3.
When I first heard about the Fosi Audio ZD3, I was very intrigued and curious. Because I know that Fosi Audio has a great reputation when it comes to high quality audio products at budget friendly prices, I immediately wanted to see how the ZD3 would hold up, especially with all the hype surrounding it and considering all the features it offers, and for such an affordable price.

The ZD3 is a balanced DAC and preamp with a focus on connectivity and versatility, and it's got some impressive specs on paper for the asking price, like the ESS 9039Q2M DAC chip, Bluetooth AptX HD support, and fully balanced output.

I’ve been reviewing audio gear for a while now, and I have always found that certain products just stand out from the moment you unbox them. The ZD3 felt like one of those; the design is sleek, it is compact, and the features look promising. But of course, specs and first impressions don’t always tell the full story. So let's see if the ZD3 can live up to its hype.

Unboxing​

When the ZD3 arrived, it was packaged in a pretty large box, and unfortunately it got damaged a bit during the shipment, but other than that, the package itself is sticking to Fosi Audio's signature design style. Inside, everything was snugly placed in protective foam, which made sure that everything would arrive in perfect condition. As I opened it up, I found everything well organized, and the included items were:

• Fosi Audio ZD3 DAC
• Power cable
• USB cable
• 3.5mm to 3.5mm trigger cable
• Remote control (note: no batteries included)
• User manual

And in my case I got some additional goodies:

• Three additional JRC 4580D op amps
• A nice 7th anniversary fridge magnet

Overall, the unboxing experience was enjoyable, despite the missing batteries for the remote!

Technical Specifications​

Specs​

• Chipset: XMOS XU316, ESS 9039Q2M, QCC3031, LME49720
• Max Sampling Rate:
• USB: PCM 32bit/768kHz, DSD512
• Optical/Coaxial: PCM 24bit/192kHz
• Bluetooth: PCM 24bit/48kHz
• Output Level:
• XLR: 5Vrms
• RCA: 2.5Vrms
• Inputs: USB, HDMI (ARC), Coaxial, Optical, Bluetooth
• Outputs: XLR, RCA
• SNR: 126dB
• SINAD: ≥120dB
• THD+N: <0.00008%
• Dynamic Range: ≥123dB
• Noise Floor: ≤2μV
• Bluetooth Version: 5.0
• Bluetooth Range: ≥13m
• Bluetooth Audio Formats: aptX HD, aptX, AAC, SBC
• Power Supply: DC 12V 1.5A
• USB Compatibility: Windows 7-11 (some drivers needed), Mac OS X, Linux

Chipset and Internal Components​

The Fosi Audio ZD3 is powered by a combination of chips for different purposes. It uses the ESS 9039Q2M for its DAC duties, along with an XMOS XU316 chip for handling the USB, and a Qualcomm QCC3031 chip for Bluetooth, which gives great wireless audio, although it lacks the LDAC codec and maxes out at 24bit/48kHz. And there are also preinstalled TI LME49720 op amps inside.

If you are into op amp rolling, you can swap these for others, like the JRC 4580D, which I have received, and I'll cover the sound differences in the sound section. There is also a preamp bypass switch on the bottom of the unit, which allows you to bypass the preamp section if you want a different preamp.

Features​

The ZD3 is absolutely loaded with features, including Bluetooth 5.0 for wireless streaming and multiple other inputs: USB, HDMI (ARC), Coaxial, and Optical.

It supports aptX HD, aptX, AAC, and SBC codecs, making it versatile for different sources, although it is a bit disappointing to see that it doesn't support LDAC. And one of the things I really like is the included remote control (unfortunately no batteries included...). It is really handy and offers pretty much full control: power on/off (although I must note that I have noticed that the DAC keeps on getting warm even when it is turned off for some reason...), screen brightness, mute, volume control, track navigation (next/previous), play/pause, and input switching (COAX, Optical, USB, HDMI, and Bluetooth).

The ZD3 also has trigger in and out ports, which are useful for setting it up with other equipment.

Build Quality and Screen​

The ZD3 has a solid full metal build and it feels premium despite its compact size and weight, although I immediately noticed that with a light taps with my finger on the casing, it makes a ringing sound, but even though I was using it on the same desk as my speakers, it didn't have any effect on the sound, and the silicone legs are doing a great job at preventing vibrations.

The front screen is clear, showing key info like volume, input, and file format. You can keep the screen on or turn it off entirely via the remote, which is a nice touch when you want a distraction free setup, but it could have been nice if it had some brightness levels.

Sound Performance​

The Sound​

The default sound of the Fosi Audio ZD3 (with the TI LME49720 Op Amp) is maybe slightly toward warmth, but it’s still pretty neutral overall. It definitely gives a clean, natural sound with just a hint of warmth that, in my opinion, adds a bit of musicality that makes the sound less dry, I would say. The overall balance makes it versatile for a wide range of music without feeling overly colored, but of course the biggest change in the sound will come from the AMP itself and not from the DAC or the preamp, so it's there where the real choice should be.

Maybe if there was an app with the option for EQ or even a filter, it could have been nice and bumped up the overall value even more, but for now we will have to stick with third party EQ apps.

Technical Aspects​

Technically, the ZD3 is top notch for the asking price. There is absolutely no buzz or hiss, and the signal is extremely transparent and clean. The DAC keeps the background completely silent, which allows all the details in the music to come through clearly. Everything feels very clean and accurate, with excellent separation and precision. Fosi really impressed me here. The fact that it has so many features, which also adds to the product's cost, and the fact that it performs incredibly well, without too many compromises, and for this price, it's truly amazing!

Op Amp Rolling (JRC 4580D)​

When I switched to the JRC 4580D op amps, the changes were quite little. The sound became in my opinion a bit more balanced and perhaps slightly less warm, with the bass feeling a touch tighter. The difference is very small and barely noticeable unless you are really listening for it. It makes it just a tiny bit less warm, but the overall signature remains close to the original.

Conclusions​

To wrap things up, I have to say that I really enjoyed my time with the Fosi Audio ZD3. Its sound is very neutral and clean yet maybe slightly warm, making music feel natural and fairly engaging. The technical performance is impressive, with no buzz or hiss to the sound and with perfectly black background without any unwanted noises.

I also really appreciate the option to roll op amps, even if the changes are not that big and may even be unnoticeable for some people. And the fact that it has so many different inputs, which allows me to instantly switch between devices such as my TV, PC or even my phone via Bluetooth.

Even though the ZD3 has a few minor drawbacks, I think they are pretty easy to overlook since nothing is perfect in our world and they are really not that big. Overall, I really believe the ZD3 is a great choice for anyone in the market for a versatile DAC with plenty of features at a good price.