Fosi ZD3 - balanced DAC with HDMI ARC

[myusernameislove]

As no dedicated thread exists for this Dac, lets create it.

Homepage.
Head-Fi reviews with specs.

Main features that separate it from the herd:

• upgradable op-amps
• HDMI Arc input (TV connection)
• low price
• possible power supply upgrade

Direct competitors (dedicated stereo dacs with HDMI Arc input, as of April 2025):

• SMSL DO100 Pro (similarly priced, not upgradable)
• SMSL DO200 Pro (pricier, not upgradable)
• Ferrum Wandla (very pricey)

Related threads:

• Fosi Audio ZD3 - my perspective (review)
• discussion about subjective audio quality benefits of Arc connection over Optical connection with TVs that can decode latest surround audio formats from DTS and Dolby and downmix them to PCM stereo

Swappable op-amps - comparison videos:

• Official Op-Amps test 1
• Official Op-Amps test 2
• Official Op-Amps test 3
• Official Op-Amps test 4
• Late Night Unboxing - comparison video 1
• Late Night Unboxing - comparison video 2
• Late Night Unboxing - comparison video 3
• VirtualHifi - comparison video 1
• VirtualHifi - comparison video 2 (with ZA-3, not ZD3)
• VirtualHifi - comparison video 3 (with ZA-3, not ZD3)

That should let this thread start nicely.

 

[myusernameislove]

ZD3 came and first thing I noticed is that there is big difference between ZD3 and DO100 Pro in tonality: ZD3 is brighter and more pristine, with more prominent upper mids and highs and much more clarity, DO100 Pro is darker and more bass heavy, also warmer, with less focus on high regions which I prefer on my very bright headphones.

With standard dense sounding headphones I think you would much prefer ZD3 over Do 100 Pro, but stock opamps give the sound some joyful flavour that is better to be removed by more neutral sounding op-amps such as those from Sparkos or VirtualHifi (if I evaluated them correctly from youtube demos). V7V Dual opamps sound to me (from youtube demos) heavier in bass and give some heft to the soundstage, which may be the thing I want or need.

So I am waiting for two VirtualHifi Supersonic V2 op-amps and Burson V7V Dual op-amps to arrive, and also for chinese linear power supply and meanwhile I will give it some time to burn-in. If synergy fails, no matter what I try, I will know that I made mistoke and I should have gone with Laiv uDAC instead.

 

[myusernameislove]

With V7V dual opamps and stock power supply ZD3 has same tonality as DO100 Pro (plenty of bass), but a little narrower soundstage which is not as immersive sounding as DO100 Pro's soundstage. Fosi is little bit clearer, also more sterile sounding than DO100 Pro with these opamps. I am waiting for LPS and Virtualhifi opamps. I still like stock DO100 Pro more, especially due to its soundstage realism and its pleasant warmth and density combined with enough clarity and fidelity.

 

[myusernameislove]

With linear power supply - ZD3 gets significant bump in detail retrieval, clarity, outlines of notes, darker background and certain authority and gets way ahead of DO100 Pro in all of these technical aspects of music delivery. But the result still does not match DO 100 Pro's very pleasant type of soundstage that has stronger middle image (and taller) which is nicely supported by weaker (rolled off) sides. With V7V opamps ZD3 has quite flat, analytical type of image. I think this might be related to the opamps (V7V) and so I am eagerly waiting for Virtualhifi opamps and if those do not improve on that, I may order also V7C opamps to see if this characteristic that makes music sound too flat and boring can improve.

 

[myusernameislove]

With VirtualHifi Supersonic V2 opamps (immediate impressions) - sound is less cold and less clinical then with Burson V7V Dual opamps. It does sound more natural. Tonality is perfect and also very neutral. Soundstage imaging is not as flat-wide and empty in the middle as with V7V, soundstage is slightly more filled in the middle (which is big big plus), without loosing on the width of the sides. It does not sound so completely wide, empty, dynamic and cold. Similar airiness as with V7V and very good detail retreival remains. I liked it straight away better then V7V Duals.

But SMSL DO 100 Pro right now sounds more pleasing still. Why? Its sound is noticeably softer and a little warmer and noticeably denser especially in the middle (at the expense of the sides) and has bolder bass extension. DO 100 Pro also sounds slightly more tall in its middle, which is great trait for solos of trumpets, voices or guitar, because sound comes from bigger height. But this does not mean that ZD3 has bad soundstage - no, especially with Supersonic V2 opamps (even without proper burn-in) it has overall wider and biger and nicer image, which lacks some CENTER tallness and CENTER focus of DO 100 Pro and... it also lacks some depth as if the painting was done on flatter surface. But not entirely flat. DO 100 Pro does not sound that flat. ZD3 notes also sound less hefty and simpler (less plastically 3Dimensional) in comparison to DO 100 Pro notes.

But all these negatives I wrote about ZD3 are only relative to its competitor and to the fact that DO 100 Pro is oriented slightly differently in the market. DO 100 Pro is kinda HiFi consumer grade product, while fully upgraded ZD3 aims for audiophile grade on cheap. DO 100 Pro has its own negatives: softer sound means softer sound, which means less attack and less note separation. Focus on center image lessens its "audiophile gradity" even further ... for the sake of musical enjoyment.

So I might still prefer DO 100 Pro but ZD3 gained some interesting traits that make it usable for me. I can enjoy it even though it sounds more neutral and less immediately pleasing than DO 100 Pro does. Lets see how it improves in few weeks or months of op-amp burn-in. Later I may try to buy even Burson V7C Pro Dual opamps, as I probably should have buy them straight away instead of V7Vs. Stay tuned.

ps Sorry if I contradict myself on some points. I try this review to be as honest as possible during the upgrade process. It would be nice to have opportunity to buy Geshelli dac and apply same upgrades to it someday.