Fosi Audio ZD3 Balanced DAC Review

[ManniX]

My worry is that the volume control on this Fosi is digital, and may fail to send full gain into the power amp. Another worry is how hot the Fosi may get, but that's less of a concern.

Seems to output 4V, isn't enough info?
Quoting Amir: "Competitors use 4.2 volt output which uses the best dynamic range of the audio analyzer. If Fosi had done that, it would probably extract another half a dB of SINAD"
I wouldn't worry about getting too hot, it barely gets warm.

 

[JFByers]

Seems to output 4V, isn't enough info?
Quoting Amir: "Competitors use 4.2 volt output which uses the best dynamic range of the audio analyzer. If Fosi had done that, it would probably extract another half a dB of SINAD"
I wouldn't worry about getting too hot, it barely gets warm.

Thanks for your response!

Are you responding to both my queries (I can't tell)?

4V is enough output for me. To be explicit about my volume question: How likely is the volume to reset itself to 0dB if there is a power outage or some glitch?

(EDIT: I see the problem. My question has a typo! My fault. Instead of ..."may fail to send..." I should have written ..."may fail AND send." In other words I'm wondering if I'll get full gain inadvertently and blow up speakers etc.).

Regarding the physical temperature of the device, your answer is very clear -- I appreciate it!

 

[ManniX]

(EDIT: I see the problem. My question has a typo! My fault. Instead of ..."may fail to send..." I should have written ..."may fail AND send." In other words I'm wondering if I'll get full gain inadvertently and blow up speakers etc.).

I get it now; wouldn't know. I guess it's nothing to worry more than the usual.
There is also an anti-pop noise filtering; it works pretty decent, when it pops due to codec change or else it's very mild.

I also had an incident with static electricity, I didn't discharge before touching the volume knob.
I could see the electric arc, pretty strong.
The ZD3 switched itself off with no noise on the speakers; switched back on without any issue.
So it seems pretty sturdy.

 

[hoverdonkey]

Thanks for your response!

Are you responding to both my queries (I can't tell)?

4V is enough output for me. To be explicit about my volume question: How likely is the volume to reset itself to 0dB if there is a power outage or some glitch?

(EDIT: I see the problem. My question has a typo! My fault. Instead of ..."may fail to send..." I should have written ..."may fail AND send." In other words I'm wondering if I'll get full gain inadvertently and blow up speakers etc.).

Regarding the physical temperature of the device, your answer is very clear -- I appreciate it!

I use my ZD3 straight into a power amp with no issues.

I always power on a new DAC before connecting it to the amp to make sure it is in non-bypass mode and that volume is at zero. One DAC I had was initially set to max volume! That was either the ZD3 or the SMSL DL200 before it, can't remember now.

 

[JFByers]

OK thanks everyone for the help!

Regarding the op amps: I am unaware of any data supporting that there would be an audible difference. A difference that might exist is heat.

Has anyone determined if any op amps generate more heat than others in this application? Since my stuff is on 24/7 that might be of practical interest. I saw above (thanks!) that the as-delivered setup doesn't run hot, which is great. Anyone played around with op amps looking at heat?

 

[VintageFlanker]

I am unaware of any data supporting that there would be an audible difference

Because there's none. @amirm measurements show stellar performance with stock OPAmps already. My advice is that you should stick to these and call it a day.

 

[ManniX]

Has anyone determined if any op amps generate more heat than others in this application? Since my stuff is on 24/7 that might be of practical interest. I saw above (thanks!) that the as-delivered setup doesn't run hot, which is great.

The ZD3 gets barely warm, I wouldn't be concerned about heat.
If you are worried about reliability running 24/7, just do not go with any discrete op-amp.

I would keep the default 49720s, they are excellent.
I've tested the Sparkos SS3602 and it doesn't change a thing on the RCA output.
On the XLR channel, where the noise floor is much lower, the SS3602 is more noisy at higher frequencies.
Couldn't hear anything different about sound, all well below audible level and only detectable via measurements.
Considering 3 x SS3602 are much more expensive than a ZD3, doesn't look like a good deal.

 

[JFByers]

Aha! That's very informative. OK so the plan is now to do... nothing. Just use the device and live life.

 

[JFByers]

UPDATE:

I'm glad I posted here and was cautioned.

Some maniac shipped the unit such that when I turned it on, volume was MAX.

I set the volume to minimum and pulled the plug and waited a bit to see what happens when the unit is powered up again, trying to simulate a power outage. It went back to minimum and not max, which is encouraging.

My system is now PC optical output --> Fosi ZD3, then using the XLR outputs --> Crown XLS1502 XLR inputs.

The Crown gain knobs are at 9 o'clock and I am using it to drive 90dB efficient speakers. The system isn't lacking for power and now I also have a useful volume knob on the Fosi since that's my preamp too.

The channel imbalance that annoyed me with the otherwise excellent Nobsound passive is gone, and I have more turning to do on the volume knob to go from minimum to maximum volume. Plus I now have 4V max in theory into the Crown's XLR inputs vs. at most half that previously.

So far, so good. Everything stays on all the time, so we'll see what happens (hopefully nothing bad!...). My tweeters are EV T-35 and I'm not keen on wrecking them but hey, they've come this far and have played flat out before, and if things go bad I can look into using more modern drop-ins like the Klipsch folks do (my speakers aren't Klipsch, incidentally).

This is the kind of situation that arises when one uses a pro amp and 80s speakers with 30 cm woofers for their computer audio...

I'm impressed with the feel of the Fosi, it's solid.

Thanks all!

 

[hoverdonkey]

UPDATE:

I'm glad I posted here and was cautioned.

Some maniac shipped the unit such that when I turned it on, volume was MAX.

I set the volume to minimum and pulled the plug and waited a bit to see what happens when the unit is powered up again, trying to simulate a power outage. It went back to minimum and not max, which is encouraging.

My system is now PC optical output --> Fosi ZD3, then using the XLR outputs --> Crown XLS1502 XLR inputs.

The Crown gain knobs are at 9 o'clock and I am using it to drive 90dB efficient speakers. The system isn't lacking for power and now I also have a useful volume knob on the Fosi since that's my preamp too.

The channel imbalance that annoyed me with the otherwise excellent Nobsound passive is gone, and I have more turning to do on the volume knob to go from minimum to maximum volume. Plus I now have 4V max in theory into the Crown's XLR inputs vs. at most half that previously.

So far, so good. Everything stays on all the time, so we'll see what happens (hopefully nothing bad!...). My tweeters are EV T-35 and I'm not keen on wrecking them but hey, they've come this far and have played flat out before, and if things go bad I can look into using more modern drop-ins like the Klipsch folks do (my speakers aren't Klipsch, incidentally).

This is the kind of situation that arises when one uses a pro amp and 80s speakers with 30 cm woofers for their computer audio...

I'm impressed with the feel of the Fosi, it's solid.

Thanks all!

Glad you caught it!

Yes, both the ZD3 and DL200 are solid at remembering the the volume through power cycles.

UPDATE:

I'm glad I posted here and was cautioned.

Some maniac shipped the unit such that when I turned it on, volume was MAX.

I set the volume to minimum and pulled the plug and waited a bit to see what happens when the unit is powered up again, trying to simulate a power outage. It went back to minimum and not max, which is encouraging.

My system is now PC optical output --> Fosi ZD3, then using the XLR outputs --> Crown XLS1502 XLR inputs.

The Crown gain knobs are at 9 o'clock and I am using it to drive 90dB efficient speakers. The system isn't lacking for power and now I also have a useful volume knob on the Fosi since that's my preamp too.

The channel imbalance that annoyed me with the otherwise excellent Nobsound passive is gone, and I have more turning to do on the volume knob to go from minimum to maximum volume. Plus I now have 4V max in theory into the Crown's XLR inputs vs. at most half that previously.

So far, so good. Everything stays on all the time, so we'll see what happens (hopefully nothing bad!...). My tweeters are EV T-35 and I'm not keen on wrecking them but hey, they've come this far and have played flat out before, and if things go bad I can look into using more modern drop-ins like the Klipsch folks do (my speakers aren't Klipsch, incidentally).

This is the kind of situation that arises when one uses a pro amp and 80s speakers with 30 cm woofers for their computer audio...

I'm impressed with the feel of the Fosi, it's solid.

Thanks all!

Glad you caught it!

 

[NeLey169]

@Fosi Audio
When I am using Fosi ZA3 and ZA3, is it possible to switch the bypass mode of ZD3 or switch the XLR/RCA input modes without turning it off?

I heard there are cases of chip damage due to switching between mono and stereo mode while in use

 

[Owis]

If I run RCA out to one amp and XLR to another amp…there is no potential risk doing this correct? Is this the same for all preamps…there doesn’t appear to be an ‘output’ selector.

 

[ManniX]

is it possible to switch the bypass mode of ZD3 or switch the XLR/RCA input modes without turning it off?

The position suggests not but I don't remember having seen it explicitly excluded.

If I run RCA out to one amp and XLR to another amp…there is no potential risk doing this correct? Is this the same for all preamps…there doesn’t appear to be an ‘output’ selector.

No risks, both output works at the same time, no selection

 

[komhst]

Can someone tell me the dimensions of the ZD3 DAC ?

 

[GXAlan]

Can someone tell me the dimensions of the ZD3 DAC ?

Is there something specific you need, like the dimensions of the rubber feet or protrusion or the volume knob or BT antenna?

 

[komhst]

Thank you very much!

 

[Brian Hall]

Why does type C matter that much to you?

Because everything uses type C now and digging through closets to find the stupid type B cables is a pain.

 

[komhst]

Why USB type B insted of type C

Because USB type B has much higher mechanical strength. So it's a much better choice than type C since there is no lack of space.

 

[GXAlan]

Because USB type B has much higher mechanical strength. So it's a much better choice than type C since there is no lack of space.

They do make USB-C cables with captive screws, although there seems to be two standards.

All the old-school cables like VGA, DVI, 9- and 25-pin serial/parallel had screws and we didn’t have problems with that.

 

[jjk1]

Hello all
I just bought this DAC and have a question for the forum. I’ve read that both balanced and unbalanced outputs are active.
I’d like to try to connect 2 unbalanced amps (an integrated and a Wiim mini actually- just to EQ tv) . I assume the balanced output voltage is higher? Is this true? Would the typical cables that convert a balanced connection to RCA work or would I need to worry about overloading the the unbalanced line input on my preamp? The zd3 would be in bypass mode.
would I just need cables or would I need a converter of sorts?
Thanks
JJK