Fosi Audio ZD3 Balanced DAC Review

[ManniX]

Forgot that in the meantime the ZD3 went back to 160€, bought a new one.
Nothing else that I like in this price range and I miss it.
Let's hope I'll be more lucky with this unit, should arrive after tomorrow.

 

[C0mbat]

View attachment 424805

I've been enjoying zd3 for around a month since I got it for a pretty good black friday deal. I know there are other dacs in the market that are designed "better" but my priority was a dac that I could play with.

I have replaced the switching adapter to a linear power supply which I already had. I think upgrading the stock power to anything better is the first thing that you wanna do.

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I also swapped all LME49720 to discrete op amps.
LME49702s are great op amps with great sound and there is absolutely no good reason not to keep them, but then this is just a hobby so..

I also have other good quality chip and discrete op amps such as opa1612, ad8620bp, sparkos, etc. and this is how I settled for now.

I don't really feel any noticeable difference but I just like how it is for my personal preference.

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I added a ground path using and soldered bypass capacitors to both V+/- rails of each op amp.
A 14 awg copper wire, 6x 1uf/63v metallized polyester caps and 6x 10uf/25v Nichicon muse bipolar caps didn't cost much at all.

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Clearance with outer shell of the case is really cloase as seen in the photo, but doable.

I still can't really feel much difference after adding bypass caps but am happly with the marginal gain coming from peace of mind.

@blunile Do you feel that there is any perceivable difference between the ZD3 and the WiiM Ultra DAC? I've already got the WiiM Ultra so was wondering if it's worth adding this. I also have the Fosi Audio V3 Monos and I know that the XLR inputs in the Monos seem to offer lower noise so that would be an upgrade but apart from that is there anything else?

 

[GXAlan]

@blunile Do you feel that there is any perceivable difference between the ZD3 and the WiiM Ultra DAC? I've already got the WiiM Ultra so was wondering if it's worth adding this. I also have the Fosi Audio V3 Monos and I know that the XLR inputs in the Monos seem to offer lower noise so that would be an upgrade but apart from that is there anything else?

I had a small buzz on the right channel of the WiiM Ultra if I stood right next to my speaker which was absent when I used the ZD3.

The WiiM was more reliable with HDMI.

 

[Poultrygeist]

Yes indeed but to get the best you still would need to buy another two, 85€ each here, for the XLR outputs; the RCA input is connected to the XLR outputs so you maybe get something better but could be even better. At a cost of course!



I have to avoid any listening session then, I don't have the space for it

I store my OB's against the wall. When I'm ready to play them I move them to the middle of the room.

 

[blunile]

@blunile Do you feel that there is any perceivable difference between the ZD3 and the WiiM Ultra DAC? I've already got the WiiM Ultra so was wondering if it's worth adding this. I also have the Fosi Audio V3 Monos and I know that the XLR inputs in the Monos seem to offer lower noise so that would be an upgrade but apart from that is there anything else?

I added Zd3 because I wanted balanced outputs to connect to my headphone amplifier - Topping A70. After a month and a half, I barely remember how Zd3 sounded like with its stock op amps, LME49720, so I can't really tell you whether or not I felt any perceivable difference between the two. Sound signature can be perceivable between op amps with BJT and JFET inputs applied at the low-pass filter stage, however, both op amps have BJT inputs so I personally think it must be very difficult to tell the difference. In other words, I felt definately perceivable difference when I put op amps with different topologies on Zd3.

 

[Poultrygeist]

Currently at $152 on Amazon which is what I paid and I doubt the ZD3 has ever been cheaper. Mine came with three extra op amps but I never bothered with them. Instead I replaced the single stock op amp governing the RCA outputs with a Sparkos discreet. The case can't fully be opened without disconnecting the bottom switch. Some videos show disconnecting the board mounted plug while others show unscrewing the switch from the case. The former method looks the easier of the two except for the fact the plugs appear to be glued together. It would take super human strength to separate the plugs so I went with the first method which was not hard but somewhat fiddle-ly.

Using it as a preamp/DAC fronting my Bottleheads means my 3.5 watts go further than I would ever need. I love this DAC and streaming HD Amazon music from my Node has never sounded better.

 

[Thighsofsteel]

Today I installed a single Sparkos to the ZD3's RCA out put and that upgrade combined with the Astron linear regulated power supply makes for a significant improvement in SQ. In comparison it humbles my SMSL SU-9.

What model of Astron PSU did you use?

 

[Poultrygeist]

What model of Astron PSU did you use?

https://www.dxengineering.com/parts/asr-sl-15r?rrec=true

In this picture it's taking the place of noisy wall wort and greatly improving the SQ of a cheap tube preamp.

 

[Thighsofsteel]

https://www.dxengineering.com/parts/asr-sl-15r?rrec=true

In this picture it's taking the place of noisy wall wort and greatly improving the SQ of a cheap tube preamp.

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Thank you good sir.

 

[pandasonic]

Hi, Have you managed to get rid of the glitch/echo? I have updated mine to v1.06 yesterday, and all seemed to be fine and dandy, and then suddenly, while using HDMI Arc, there it went again... some weird echo...

Nope. No luck for me. Waiting to see if Fosi releases a new firmware update. Else they've given me the option of them sending me a replacement, hoping that solves it. Haven't taken them up on that as I'm giving them some time, hoping they can fix these issues at the factory in the DACs manufactured now.

 

[Viriatusrex]

Nope. No luck for me. Waiting to see if Fosi releases a new firmware update. Else they've given me the option of them sending me a replacement, hoping that solves it. Haven't taken them up on that as I'm giving them some time, hoping they can fix these issues at the factory in the DACs manufactured now.

Hi, thank you for your answer. I've sent an e-mail to Fosi support about that issue and they answered me today by sending me the v.1.0.7 firmware version to see if that solves the problem, I haven't installed it yet though...

 

[ManniX]

Hi, thank you for your answer. I've sent an e-mail to Fosi support about that issue and they answered me today by sending me the v.1.0.7 firmware version to see if that solves the problem, I haven't installed it yet though...

Uhm, isn't suspiciously similar to what they said about v1.0.6 here?

https://support.fosiaudio.com/hc/en-us/articles/41533797670041-Experiencing-digital-glitches-or-echo

Got the new ZD3, I'm testing it with the XLR cable and the Scarlett.
Excellent like the previous unit but a bit more difference between L & R channels.

I've tested the SS3602 against the LME49720, switching them between L & R.
The SS3602 works better in the R channel than in the L and compared to the LME49720 has worse THD in both cases and better SFDR on the L.
Except that they are almost identical. I will definitely keep the LME49720 on the XLR outputs.
Now will test the SS3602 against the LME49720 on the RCA output but I don't except much difference if at all.

 

[ManniX]

Apple Senior Level support insists that the Apple TV isn't sending anything out while on standby but who knows. I suspect that Fosi is basing it on signal detect as opposed to CEC wake up command.

I tried testing with the analyzer and I couldn't wake up the ZD3 in any way.
There must be a sequence with the TV to initiate ARC and I would need to sniff it.
The analyzer has an ARC Initialization in emulation mode but it doesn't seem to work.
Problem is that I realized that I don't have anything to connect to it... my only TV with ARC was replaced with a projector.
Will try again later.

2. The knob is a real pain to remove as it is on their very tightly, but I found that using a soft covered jar opener like the one picture below works perfectly to grip it and pull forward to get it off. When doing so, don't grip the know with the recessed side, use it sort of backwards so that the side show below is towards the face plate on the dac.

Really, thanks a lot for posting this.
I didn't knew this thing even existed.
Bought it and I've never pulled out a knob so easily in my life!

 

[ManniX]

I've tested the SS3602 against the LME49720 on the RCA output.
Got confused at first, then I realized that I must have swapped the channels in the previous measurements with the SS.
The 1k Sine is so identical between them that I got the same results down to the fractional digits.
I guess the noise introduced by the RCA output circuit is higher than that of both op-amps.

Performance-wise there's no reason at all to use the SS3602 (at least my sample) on the RCA output.
On the XLR outputs it's generally worse, better to stick to the LME.

Of course makes sense if you can hear and like the coloration of the SS3602.
But it's a bit as with a good tube amp, the difference is likely due to a worsening of the signal than else.

A small win for the SS3602 is the filtering of the 50/100 Hz hum which seems to be a tad better than the LME.
In most of the measurements it's not present with the SS while it is with the LME.
But it's really a small win cause even if it's there with the LME, it's so subtle to be irrelevant.
Maybe it could matter in specific cases and with something more high-end than the ZD3.

 

[GXAlan]

For what it’s worth, Fosi confirmed that the trigger voltage for the HPD is 3.3V to 5V.

That seems perfect, so I am at a loss to why the ZD3 is waking up sometimes.

 

[Viriatusrex]

Nope. No luck for me. Waiting to see if Fosi releases a new firmware update. Else they've given me the option of them sending me a replacement, hoping that solves it. Haven't taken them up on that as I'm giving them some time, hoping they can fix these issues at the factory in the DACs manufactured now.

I'm happy to repport that the ZD3 v1.0.7 firmware update seems to have solved my echo problems and also it no longer turns on my tv after I disconnected it. I'm say I'm pleasantly surprised with the Fosi support team for having answered and provided a solution. Tried to insert the update here but the .bin format isn't supported, i'm sure it's somewhere on Fosi website, but I couldn't find it.

 

[ManniX]

I'm happy to repport that the ZD3 v1.0.7 firmware update seems to have solved my echo problems and also it no longer turns on my tv after I disconnected it. I'm say I'm pleasantly surprised with the Fosi support team for having answered and provided a solution. Tried to insert the update here but the .bin format isn't supported, i'm sure it's somewhere on Fosi website, but I couldn't find it.

Thanks for the update, very promising!
Good vibes from Fosi support, let's hope they keep this pace.
You are right v1.0.7 is not available to download, maybe they were waiting your feedback for a go decision

 

[F1 Fan]

Still unable to do any updates on Mac though ..

 

[Viriatusrex]

Thanks for the update, very promising!
Good vibes from Fosi support, let's hope they keep this pace.
You are right v1.0.7 is not available to download, maybe they were waiting your feedback for a go decision

You're welcome! Yes, after I installed the update, I listened to a couple of concerts on Youtube through HDMI ARC for about 2 hours last evening without any apparent issues, while before every 30/40 minutes or so, I would get that really distracting effect/glitch.
About my feedback, well, who knows ? Anyway, I've already given them my feedback and thanked them for the good support.
Seems we right might have a new competitor in the DAC race !

 

[GXAlan]

Mine still powers on unintentionally with 1.07 (given by Fosi email support).

Again, this is Sony A9G, AppleTV, and Fosi as connected devices using both TV or Apple Remote as system wide HDMI power down.

Not a problem with Yamaha receiver or Sonos soundbars or Monolith HTP-1 or even the WiiM Ultra (except WiiM Ultra had hum on one channel for me)