Fosi Audio ZD3 Balanced DAC Review

[medioman69]

Your account shows that you are new here, so welcome to ASR. Your comments about the display, remote and usability are welcome. However, talking about "musicality" and "sound stage" of a modern DAC will likely result in some blowback in a science-leaning forum like ASR.

To put it bluntly, your listening tests are invalid and cannot yield any reliable result. You're trying to judge a device with 120 dB SINAD - that is inaudible distortion and noise - using a tube amp which the manufacturer specs at -60 dB THD without any word about noise. That's three orders of magnitude worse than the DAC. There is no way you could tell any difference there - even if it existed.

Second, well engineered DACs are audibly transparent and have been for some time. They don't have a sound. You can randomly switch one transparent DAC for another and they will sound 100% identical. Any DAC that audibly alters the sound in any way is broken and should be repaired or replaced. After all, it failed at its one and only job: Converting digital signals to analog as precisely as possible.

If you want, you can read lots of useful information about how to properly test audio devices, how to interpret test results correctly and lots of other useful stuff on ASR. I would encourage you to do so.

You’re right. As I have wrote I report how it sound in my equipment, compared to my other DAC. Nothing more, nothing less.

 

[EJ3]

My personal review of ZD3

After trying out the Fosi Audio Box X5 phono preamp, I now have the Fosi Audio ZD3 DAC available to test thoroughly.

I added it to my listening system: Raspberry Pi with Roon as the FLAC music source, connected to the ZD3 via USB for maximum quality, and from there to the Octave V40 SE amplifier. For the listening tests, I mainly used records by Marillion, Pink Floyd, Tina Turner, Massive Attack, Eric Burdon, but also other genres and artists, evaluating it in particular in comparison with the HiFiBerry DAC+, also connected to a Raspi+Roon.

View attachment 515206

Setup and installation

As mentioned, I connected it via USB to the Raspberry Pi configured with Moode and Roon Bridge for lossless streaming, setting the ZD3 preamp bypass for a clean fixed output to the Octave V40. Integration was immediate: intuitive remote control, clear OLED display for input/volume (although a little small to read from a distance) and trigger in/out to synchronise power-up with the rest of the system.

According to the technical data sheet and measurements available online, the ZD3 is equipped with an ESS ES9039Q2M chip, with a declared THD+N of <0.00008% and SNR ≥126 dB, data that on paper should ensure excellent clarity, natural dynamics and a stable soundstage.

Some specific listening examples

Marillion: on “Kayleigh”, Fish's vocals and, on “Easter”, Steve Hogarth's vocals, although very different, appear precise and articulate; Pete Trewavas' bass is deep and rhythmic, and the guitars and keyboards are always clearly audible, with remarkable overall musicality.

Pink Floyd: ‘Shine On You Crazy Diamond’ reveals a wide spatiality, with Gilmour's synths and guitars flowing and an enveloping soundstage, which goes very well with the character of the V40 tube amplifier.

Tina Turner: her voice appears powerful and structured, without any particular sibilance, highlighting details and nuances that I had missed in other listening sessions with less refined DACs.

Massive Attack: the low electronic frequencies of Mezzanine are well present and do not “smother” the instruments and vocals, which often rise above the rest of the mix, remaining clean and captivating.

Conclusions

In my system with Raspi + Roon and Octave V40, the ZD3, compared to the HiFiBerry DAC+, clearly improves the soundstage and detail, without tiring the listener even after several hours.

Unfortunately, I have not yet had the opportunity to use it in more expensive audio systems, which I will do as soon as possible; at the moment, however, it seems to me to be the ideal DAC for those looking for reasonably priced electronics that allow them to easily experiment with op-amp upgrades if they wish.

I was satisfied with the overall result: the ZD3 is a compact and versatile DAC that surprises with its value for money, with a generally neutral and detailed sound that integrates well into good quality audio setups.

I would particularly recommend it to those who use pure digital sources (preferably lossless), because for the price, it is, in my opinion, an excellent deal.

@medioman69: welcome
and you did a very good writeup (just not exactly in line with the focus of science that this site is focused on)
But, on this site:
Scientifically speaking: your listening tests are valid to only you.
No one else's hearing and particularly hearing perceptions (which are based on many inputs from all our senses and our preconceived notions from our whole lives):
Are the same as yours.
Hence this site: to scientifically MEASURE whether or not some piece of gear is transparent or isn't transparent (meaning an exactness better than the threshold of what human hearing is capable of discerning) at doing it's job:
Delivering the output audio signal exactly as it was input (same dynamic range, frequency range, etc, etc. [as you hang around here you will take in more & more information])
It can either do that or not. If not: something is wrong with the unit (even if it is intentional, such as a 'House Sound')
If so: then the goodness (or not so goodness) of the things that you so eloquently told us about (display, remote, usability [& perhaps other things]) come into play.
Thank you for joining us and for your consideration.
And Please: When you have questions, just ask: that is how we all learned and continue learning. Someone will answer.

 

[Rainer Dynszis]

Can someone explain to me how the specs published by Fosi for the ZD3 can be better than the specs published by ESS Technology for the ES9039Q2M DAC chip that Fosi uses?

To wit, the ES9039Q2M Product Datasheet (PDF here) asserts "-120dB Total Harmonic Distortion + Noise (THD+N)", which obviously translates to 0.0001% in percentage notation, valid for the naked chip.

So how can Fosi arrive at 0.00008% aka -122 dB THD+N for the whole system, without distorting the facts?

 

[RemLezar]

Hi, the replacement ZD3 arrived today.

I can happily report the new hardware does not have the same HDMI-CEC issues with my LG TV. Previously, the ZD3 unit would automatically turn on a bit after being turned off and it would then turn the LG TV on. Turn the TV off and the whole cycle repeats. This is no longer the case and it all seems to work as it should.

For those who care, the new hardware has a longer ~4" tall bluetooth antenna. Previously, the hardware had a shorter ~2" long bluetooth antenna, that comes in the box. Couldn't find any serial numbers, manufacturing date, etc. on the box nor on the device itself.


P.S: Message from Fosi support - " Thanks for the update—great to hear your replacement ZD3 is working well with your LG TV and HDMI-CEC.
Yes, the HDMI CEC issue between the ZD3 and LG TVs has been resolved. The current shipments of the ZD3 should not have the HDMI CEC issue with LG TVs."

Interestingly, Fosi support has explicitly told me the opposite; that sending a replacement would not fix my CEC related issues. My TV is an LG C1 and I have tried two different ZD3 that both turn themselves on umpropmted, along with my TV.

They have assured me that a firmware update is being worked on but I'm not confident when or if it will be available.

At this point I wish I had forgone the "conveniences" of HDMI CEC and went with a different device altogether. Fosi support has been attentive but, as of now, there is no solution for me.

 

[RandomEar]

Can someone explain to me how the specs published by Fosi for the ZD3 can be better than the specs published by ESS Technology for the ES9039Q2M DAC chip that Fosi uses?

To wit, the ES9039Q2M Product Datasheet (PDF here) asserts "-120dB Total Harmonic Distortion + Noise (THD+N)", which obviously translates to 0.0001% in percentage notation, valid for the naked chip.

So how can Fosi arrive at 0.00008% aka -122 dB THD+N for the whole system, without distorting the facts?

Fosi might report A-weighed THD+N, while ESS does no weighing. Or they might measure at different output voltages. Also, the value from the ESS datasheet will likely not be for just the chip, but for the chip in some reference circuit which ESS implemented. So technically, it might be possible to improve the performance of the chip a tiny bit if you accept a higher parts count and/or more complex circuit around it.

Seeing that Fosi claims SINAD>120 dB while Amir's results show around 117 dB (unweighted), some form of weighing seems likely. You would need to ask'em to be sure.

 

[NeLey169]

I'm using a Fosi ZD3 DAC connected to an LG TV via HDMI Arc, and I'm experiencing a problem where the TV turns off and then restarts automatically when I turn off the DAC. How can I completely fix this?
@Fosi Audio

 

[luke2kk]

Is this DAC still recommaned in 2026 and used with Genelec 8030C/G Three?

Thanks in advance.

 

[90sNintendoKid]

Is this DAC still recommaned in 2026 and used with Genelec 8030C/G Three?

Thanks in advance.

I don’t see why not unless it doesn’t have features you require.

I still use one with optical and usb inputs.

If I remember correctly, there were reports of quirks with the hdmi arc and cec implementation and I recommend you read this thread for more details.

 

[Rainer Dynszis]

Is this DAC still recommaned in 2026 and used with Genelec 8030C/G Three?

This DAC is still recommended in 2026 and used with Genelec 8030A in this household. But then the 8030A has a volume pot, and the 8030C has not.

The problem I'd see with 8030C is that this thing invariably generates 100 dB SPL at -6 dBu input, while the ZD3's output voltage of 5 Vrms is equivalent to +16.2 dBu. In other words, its output is ~22 dB too high for these speakers, and 37 dB too high if you want to avoid long-term hearing damage.

The ZD3's volume adjustment goes from 0-80, and it gets already uncomfortably loud at 25 or so when it's hooked up to a Genelec 8030. You'll probably want to overcome this disparity one way or another. Maybe a -20 dB attenuator between the ZD3's outputs and the monitors' XLR inputs.

Another thing to consider is why you'd want the ZD3 instead of the ZH3. I wouldn't buy the ZD3 unless I need the Bluetooth or ARC input option that the ZH3 doesn't have.

 

[luke2kk]

This DAC is still recommended in 2026 and used with Genelec 8030A in this household. But then the 8030A has a volume pot, and the 8030C has not.

The problem I'd see with 8030C is that this thing invariably generates 100 dB SPL at -6 dBu input, while the ZD3's output voltage of 5 Vrms is equivalent to +16.2 dBu. In other words, its output is ~22 dB too high for these speakers, and 37 dB too high if you want to avoid long-term hearing damage.

The ZD3's volume adjustment goes from 0-80, and it gets already uncomfortably loud at 25 or so when it's hooked up to a Genelec 8030. You'll probably want to overcome this disparity one way or another. Maybe a -20 dB attenuator between the ZD3's outputs and the monitors' XLR inputs.

Another thing to consider is why you'd want the ZD3 instead of the ZH3. I wouldn't buy the ZD3 unless I need the Bluetooth or ARC input option that the ZH3 doesn't have.

Genelec G Three (B) have a dip switch for +10dB (instead of a sensivity knob). If I use this dip switch, will I be fine with the Fosi?

 

[Rainer Dynszis]

Genelec G Three (B) have a dip switch for +10dB (instead of a sensivity knob). If I use this dip switch, will I be fine with the Fosi?

I'm not sure. According to the current G Three Operating Manual, that switch makes the Speaker 10 dB louder, which is probably not what you'd want. Then again, the picture does not show a Genelec G Three that you can buy today. The picture clearly shows a specimen with LPS, recognizable from the fixed input voltage at 230 V. Today's Genelec G Three models have an SMPS, recognizable from the 100-240 V AC specification printed on the back.

Can you say which items you already have, and which items you plan to purchase at this point?

Edit: I just found out that I erred about the sensitivity of the 8030C. According to its Operating Manual you can reduce its sensitivity by 12 dB. Can you say why you'd prefer the G Three over the 8030C?

 

[luke2kk]

I'm not sure. According to the current G Three Operating Manual, that switch makes the Speaker 10 dB louder, which is probably not what you'd want. Then again, the picture does not show a Genelec G Three that you can buy today. The picture clearly shows a specimen with LPS, recognizable from the fixed input voltage at 230 V. Today's Genelec G Three models have an SMPS, recognizable from the 100-240 V AC specification printed on the back.

Can you say which items you already have, and which items you plan to purchase at this point?

Sorry, just used a picture from google search. That was clearly my mistake. I currently have the 8030C at home, but I already ordered the G Three (B) which are on the way to me. (I basically choose them over the 8030C because of more flexbility in connections, and that fact that they might have less hiss, which I read here in this forum.

When I remember correctly, someone mentioned that G Three (B) whithout using the +10 dip switch are the same like 8030C (sensitivity knob on +4, default is -6).
Just to be sure, to leave any mistakes aside, youre familiar with this sensitivty knob on the 8030C? I guess they have that INSTEAD of the volume pot.

 

[Rainer Dynszis]

I basically choose them over the 8030C because of more flexbility in connections, and that fact that they might have less hiss, which I read here in this forum.

Why, I understand that the G Three has RCA inputs in addition to XLR. I'm not sure how this translates to more flexibility. On page 5 of your 8030C manual you find a sketch how to attach an RCA source, and ready-made adapter cables are abundant and cheap. And I never heard any of our 80n0s hiss.

When I remember correctly, someone mentioned that G Three (B) whithout using the +10 dip switch are the same like 8030C (sensitivity knob on +4, default is -6).

I cannot comment on that, because I have never seen nor operated the G Three myself, and the manual doesn't say anything about their sensitivity. I have no idea how loud they are in comparison to the 80n0 line of monitors.

However, I do know the sensitivity adjustment work the other way round: -6 dBu makes the 80n0 monitor 12 dB louder than +6 dBu, because these markings designate the input voltage that translates to 100 dB SPL. The +10 dip switch on the G something makes the speaker 10 dB louder in comparison to the standard dip position, according to the manual. Therefore, if the standard sensitivity of the G Three should be the same as that of the 8030C, the +10 dip switch would change that -6 dBu standard setting to -16 dBu, not to +4.

Just to be sure, to leave any mistakes aside, youre familiar with this sensitivty knob on the 8030C? I guess they have that INSTEAD of the volume pot.

Yes, trimpots like the one on the 8030C have been used for decades on the 8040 and 8050. They just aren't a substitute for the volume pot on the 8030A because the latter's attenuation range is 80 dB instead of 12.

Speaking of 8040 and 8050, you might want to consider that these still have linear power supplies. It's only the 8030s and lower where Genelec has changed to SMPSs. I have already wondered whether I should pick up a pair of 8040s now that they are still available.

 

[Kali-]

I'm using a Fosi ZD3 DAC connected to an LG TV via HDMI Arc, and I'm experiencing a problem where the TV turns off and then restarts automatically when I turn off the DAC. How can I completely fix this?
@Fosi Audio

This is not an issue with LG, i have the same with Sony Bravia OLED, to my eyes it looks just a poorly HDMI implementation (maybe hw?)

 

[Yersinia Bestmate]

Is this DAC still recommaned in 2026 and used with Genelec 8030C/G Three?

Thanks in advance.

Why not. I'm currently using ZD3 with a pair of 20-year-old Genelec 8020A monitors. They are a good match and both perform flawlessly without any issues.

 

[pandasonic]

Anyone know if the HDMI CEC issue with ZD3 + LG TVs has been resolved? I see a lot of older complaints about the DAC turning itself back on shortly after the TV turns it off.

Yes. It's resolved in the new hardware version.

 

[pandasonic]

Q2: Should HDMI show a sampling rate on the display? The specs for the ZD3 HDMI don't mention what rates or bit depths it supports..

When connected via HDMI (HDMI cable from LG TV HDMI ARC port to Fosi ZD3) the ZD3 works just fine, but it shows "none" for sample rate (shows the sample rate for optical input), shows PCM as the format which is what my TV is set to (as it doesn't handle Dolby, DTS, etc.).

Initially my original device had the HDMI-CEC issues with my LG TV, but after I raised the issue with Fosi customer care they were nice enough to send me a replacement unit (they had fixed the issue by then) which has worked perfectly well.

They did ask me send videos of the issue so they could recreate it at their end to try and find a solution. Eventually they agreed it couldn't be fixed with a software update so sent me a new unit. Definitely had to be patient. They always responded within a day.

 

[pandasonic]

Interestingly, Fosi support has explicitly told me the opposite; that sending a replacement would not fix my CEC related issues. My TV is an LG C1 and I have tried two different ZD3 that both turn themselves on umpropmted, along with my TV.

They have assured me that a firmware update is being worked on but I'm not confident when or if it will be available.

At this point I wish I had forgone the "conveniences" of HDMI CEC and went with a different device altogether. Fosi support has been attentive but, as of now, there is no solution for me.

I used it via the optical input until the replacement came. Had no issues whatsoever, except the additional step of having to turn the unit on and off using the Fosi remote.

 

[pandasonic]

Dear @amirm,

Is there a test by which you can measure how the DAC or preamp performs (digital in, analogue out) over its volume control range?

I was hoping to learn how the device performs (digital in, RCA or balanced analogue out) when it's (the ZD3 in this case) volume is set to 40, 50, 60, 70...,100%, while the digital input (16-bit, 44.1 kHz) to the DAC/preamp is at max volume (16-bit max bit depth, 0 dbfs).

I ask as I noticed this statement in the specifications of the Wiim Pro Plus streamer you shared.
Audio Quality; Description - Analogue Audio Output: ... You wont lose precision when using volume control with analogue output for 16-bit audio.

Thank you.