Fosi Audio ZD3 Balanced DAC Review

[Art of sound]

Finally replacing my k7 dac attached to my TV. for consumers hdmi arc is a necessity but audiophiles its a convenience. besides, i don't need to get up and change the volume. Too bad this thing has no high pass filter

 

[BlueGuerrilla]

It's pretty nice to use OPA1622 to use XLR.

 

[Bloomer]

Quick question (2 actually):

I bought a ZD3 from Fosi last Thursday and have not been able to get the HDMI port to function. Display idicates HDMI, None for Sampling Rate and PCM.

I've connected cd, dvd, bluray players, nvidia shield, TV directly to the port and no sound, no indication HDMI is recognized in the display..

The normal configuration is through an HDMI switch to the TV (LG G3) , which functions perfectly for all inputs, audio works fine.

SPDIF from the switch works fine, for any input, so the switch works correctly.

Q1: Fosi Support appears to be some phone addict blasting me with inane, repetitive questions, so, just to be sure I'm not insane, the HDMI port should work with ARC from TV, right? And all the othert stuff I connected directly?

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..

I bought this because of the HDMI input and good review by Amir. My JD Labs Atom 2 was having stuttering problems syncing with the switch. A firmware upgrade mostly fixed that, but it didn't sound right, unstable image, suck outs, and poor sound stage. The ZD3 is clearly better sounding, good sound staging, smooth presentation, solid imaging, so I'd like to keep it.
edit: I'd like to get another one that works correctly.

 

[Bloomer]

I love the dac for how it sounds but will replace because of high standby and no control over display.

The display can be turned off with the remote, upper left button. No dimming I know of.

 

[Art of sound]

Quick question (2 actually):

I bought a ZD3 from Fosi last Thursday and have not been able to get the HDMI port to function. Display idicates HDMI, None for Sampling Rate and PCM.

I've connected cd, dvd, bluray players, nvidia shield, TV directly to the port and no sound, no indication HDMI is recognized in the display..

The normal configuration is through an HDMI switch to the TV (LG G3) , which functions perfectly for all inputs, audio works fine.

SPDIF from the switch works fine, for any input, so the switch works correctly.

Q1: Fosi Support appears to be some phone addict blasting me with inane, repetitive questions, so, just to be sure I'm not insane, the HDMI port should work with ARC from TV, right? And all the othert stuff I connected directly?

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..

I bought this because of the HDMI input and good review by Amir. My JD Labs Atom 2 was having stuttering problems syncing with the switch. A firmware upgrade mostly fixed that, but it didn't sound right, unstable image, suck outs, and poor sound stage. The ZD3 is clearly better sounding, good sound staging, smooth presentation, solid imaging, so I'd like to keep it.
edit: I'd like to get another one that works correctly.

connect to the earc port directly on the TV without the switch and see if the tv remote controls the volume on zd3.

 

[Bloomer]

I love the dac for how it sounds but will replace because of high standby and no control over display.

connect to the earc port directly on the TV without the switch and see if the tv remote controls the volume on zd3.

Doesn't control volume your suggested way. I've been using the ZD3 as just a DAC, in bypass mode, but with volume switch on, nothing happens. Volume works with ZD3 remote. Yesterday I tried CD player coax output to ZD3 coax input, works fine. So, seems HDMI input is dead.

This thing is pretty simple, not much you can do with it. Good switch, Orei 4927 eARC.

I bought a ZD3 from Parts Express yesterday, lower price and I've never had an issue with returns buying from them for over a decade.

A bit OT but I would highy disrecommend buying direct from Fosi. Four new emails later, I'm still trying to get a return authorization. That makes 9 total contacts.

 

[Bloomer]

Doesn't control volume your suggested way. I've been using the ZD3 as just a DAC, in bypass mode, but with volume switch on, nothing happens. Volume works with ZD3 remote. Yesterday I tried CD player coax output to ZD3 coax input, works fine. So, seems HDMI input is dead.

This thing is pretty simple, not much you can do with it. Good switch, Orei 4927 eARC.

I bought a ZD3 from Parts Express yesterday, lower price and I've never had an issue with returns buying from them for over a decade.

A bit OT but I would highy disrecommend buying direct from Fosi. Four new emails later, I'm still trying to get a return authorization. That makes 9 total contacts.

Don't want to hijack this thread but I really want Fosi's dreadful customer service to be highlighted:
email 10: send us a video proving what you say is true and we'll consider a refund. We'll consider honoring our own return policy. What a joke.
Really?! Like a vid can't be edited to show whatever one wants.
Don't buy direct from Fosi.

 

[Timegroove]

Don't want to hijack this thread but I really want Fosi's dreadful customer service to be highlighted:
email 10: send us a video proving what you say is true and we'll consider a refund. We'll consider honoring our own return policy. What a joke.
Really?! Like a vid can't be edited to show whatever one wants.
Don't buy direct from Fosi.

Check that you are really using ARC/eARC-port on the TV. You can not connect Shield directly to the ZD3, it has to be ARC.
And you probably have to enable SIMPLINK (HDMI-CEC).

 

[Bloomer]

Both are true.
I got one from parts express saturday and it works fine.
I sent Fosi their ZD3, my card company can fix this if they balk.
LOL, customer "support" resent their first two messages as new over the weekend. Smells like AI slop, none of it made sense, Oh well.

 

[tranceFusion]

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.

 

[Twenty5177]

I had the following experience with the ZD3 and my LG C4 (55'') so far. CEC and power sync worked until I switched the LG off, then the ZD3 turned itself back on and thus the C4. This happened twice.
Howevever since then, without changing anything, it just works as expected: Apple TV remote On -> C4 turns on -> ZD3 turns on and volume control works via ATV remote to the ZD3. Apple TV remote Off -> C4 turns off -> ZD3 turns off.
I hope it stays this way.

I asked the support what to do if it occurs again and received this answer (haven't tried any steps yet):

Could you please provide your order number? If the product has an SN code label on the bottom, please kindly provide us with the serial number.

Could you please confirm if the firmware version you are currently using is the latest one: v1.0.8? Open the driver Fosi Audio USB Audio Device Control Panel, go to Info → Revision, and check whether it is the latest version.

In the meantime, please try the following steps again to see if they resolve the issue:

1. Reinstall the firmware: https://drive.google.com/file/d/1aRwxuqInKDOvNN2RdoM95LVKrvNVaxpM/view?usp=drive_link

You can watch the video through the link: https://drive.google.com/file/d/1DQC7wX2rybB_CsDta1uBy2f14J6vfDyi/view?usp=drive_link

2. Set the TV audio output to HDMI instead of Auto. Change the TV audio setting to Pass Through instead of Stereo or Auto.

3. Switch to OPT, COA, or BT mode.

4. Change ZD3 to another input mode, turn off the TV with its remote, then power off the ZD3 using either its remote or the front panel button (this will shut down all connected devices).

5. Disable the HDMI-CEC function.

 

[tranceFusion]

I had the following experience with the ZD3 and my LG C4 (55'') so far. CEC and power sync worked until I switched the LG off, then the ZD3 turned itself back on and thus the C4. This happened twice.
Howevever since then, without changing anything, it just works as expected: Apple TV remote On -> C4 turns on -> ZD3 turns on and volume control works via ATV remote to the ZD3. Apple TV remote Off -> C4 turns off -> ZD3 turns off.
I hope it stays this way.

I asked the support what to do if it occurs again and received this answer (haven't tried any steps yet):

Interesting.. how long have you had the zd3?

 

[Twenty5177]

Interesting.. how long have you had the zd3?

A few days now. The power loop hasn't occured since my post and I'm happy so far, except that you can't dim the display permanently.

 

[ROOSKIE]

ZD3 is $122.39 on eBay right now using their extra 20% off coupon code, I'd go buy now if I was looking.

Pardon Our Interruption...

 

[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.

Fosi says the issue is sorted in the new hardware they produce. Cannot be fixed with a firmware update in the older hardware manufactured - first half 2025 and older.

They have offered to send me a replacement. Waiting for it to arrive. Faced some issues with the Chinese customs and got turned back. They are not trying to reship it.

 

[Twenty5177]

Fosi says the issue is sorted in the new hardware they produce. Cannot be fixed with a firmware update in the older hardware manufactured - first half 2025 and older.

They have offered to send me a replacement. Waiting for it to arrive. Faced some issues with the Chinese customs and got turned back. They are not trying to reship it.

Do you know how to differentiate the serial number and manufacuring date?

 

[pandasonic]

Do you know how to differentiate the serial number and manufacuring date?

No, I don't. Just took their (customer support) word for it.

Edit: in my previous post I accidentally types "they are not trying to reship it, when I meant they are *now* trying to reship it.

 

[pandasonic]

Do you know how to differentiate the serial number and manufacuring date?

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."

 

[medioman69]

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.

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.

 

[RandomEar]

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.

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.