Fosi ZH3 Balanced Headphone Amp & DAC Review

[ejr]

Unless you have a system like mine (by Genelec) in which you connect both outputs to the subwoofer, which handles the bass and routes the other frequencies to your L and R channels. That way your speaker system handles everything and you can use whatever components you like.

 

[awesome_sheeps]

Hi all! May I please confirm that the ZH3 would meet my following needs?

I'm trying to find a device that allows for inputs via analogue (RCA cable) and digital (SPDIF cable) to then output via RCA cable or a 4.4 mm jack.

Basically, to be able to listen to music from my turntable (AT-LP70XBT, which has a built-in pre-amp) or my PC, via my speakers (audio engine A5+), or via my IEMs.

It seems like the ZH3 will work for this purpose, but it seems that I might need to get a pre-amp(?) to directly adjust the volume of the music from my turntable, rather than doing it via the ZH3 or speakers?

 

[bungle]

It seems like the ZH3 will work for this purpose, but it seems that I might need to get a pre-amp(?) to directly adjust the volume of the music from my turntable, rather than doing it via the ZH3 or speakers?

I am not 100% sure. But I think you should be able to adjust volume of RCA output when using RCA input with ZH3 in AUX (pre-amp) output mode. The manual says:

So it seems like there are less "steps" when adjusting analog volume vs. digital. The analog volume probably happens in analog domain, whereas the digital volume happens in DAC chip.

 

[esk]

Hi all! May I please confirm that the ZH3 would meet my following needs?

I'm trying to find a device that allows for inputs via analogue (RCA cable) and digital (SPDIF cable) to then output via RCA cable or a 4.4 mm jack.

Basically, to be able to listen to music from my turntable (AT-LP70XBT, which has a built-in pre-amp) or my PC, via my speakers (audio engine A5+), or via my IEMs.

It seems like the ZH3 will work for this purpose, but it seems that I might need to get a pre-amp(?) to directly adjust the volume of the music from my turntable, rather than doing it via the ZH3 or speakers?

Fiio K7 can do this. I have a similar kind of setup with it. But with it, LO is always fixed volume. So you need another preamp with volume control. I have it connected to Wiim Ultra.

And as stated above, ZH3 can output to AUX with volume control, LO without volume control or PO balanced 4.4 mm jack.

 

[NeLey169]

Ah, you meant High, Medium and Low setting, according to manual:

View attachment 481362

View attachment 481352
You can download the whole manual from here:

ZH3 | Welcome to our Support

support.fosiaudio.com

PO = Phone Out or Pre-out ??

 

[Grimoire]

PO = Phone Out or Pre-out ??

Headphone out.

 

[ejr]

Headphone out.

I bet it makes more sense in Chinese.

 

[Homard]

My unit runs very hot. Have others experienced that?

 

[Grimoire]

My unit runs very hot. Have others experienced that?

More like quite warm with mine, and that's just using headphones. It is a little worrying.

 

[onethreetwowaitthatswrong]

More like quite warm with mine, and that's just using headphones. It is a little worrying.

There has been an answer to this issue earlier in the thread (see below, 1st point). Although I couldn't say if the expected "slight heat" mentioned there is of the same scale that the warmth you talk about

Yes, thank you very much for your feedback. We would like to address some of the points you raised:

1/2. The ZH3's headphone amplifier circuit is a Class A/B dual-power fully discrete push-pull differential complementary balanced circuit. Therefore, it may generate slight heat even when no music is playing. Please rest assured that we have conducted rigorous testing, and this will not affect the normal operation or lifespan of the device.

3. Yes, considering that some customers may prefer linear power supplies, we have used a DC 12V power interface to allow users the flexibility to switch to different power supply methods if desired.

4. We sincerely apologize for any inconvenience caused. However, we are not entirely clear about the issue you mentioned. Could you please provide more detailed information about the specific problem?

5/6. The device features five levels of screen mode adjustment. The "2min" setting refers to the auto screen-off mode. The other four levels allow you to freely adjust the screen brightness.

7. When operating in a non-BYPASS mode, the signal is affected by EQ adjustments, so a change in SNR is normal as the music signal is altered. However, dynamic range should not be significantly affected. Our analog input-to-output path is fully analog, with no ADC conversion involved.

 

[NeLey169]

Headphone out.

If I use ZH3 as DAC or Preamp will that EQ affect the speakers?

 

[Parky]

Hi all! May I please confirm that the ZH3 would meet my following needs?

I'm trying to find a device that allows for inputs via analogue (RCA cable) and digital (SPDIF cable) to then output via RCA cable or a 4.4 mm jack.

Basically, to be able to listen to music from my turntable (AT-LP70XBT, which has a built-in pre-amp) or my PC, via my speakers (audio engine A5+), or via my IEMs.

It seems like the ZH3 will work for this purpose, but it seems that I might need to get a pre-amp(?) to directly adjust the volume of the music from my turntable, rather than doing it via the ZH3 or speakers?

I found the rca audio out to be really low and I am using a p4 to amplify the zh3. I have a post about this on the forum. Your powered speakers may need to be set to higher volume. I would buy the zh3 on amazon and see if it needs a preamplifier first as they have a good return policy.

 

[ThsM]

If I use ZH3 as DAC or Preamp will that EQ affect the speakers?

no

 

[bungle]

I got my ZH3 today. I ordered it through Amazon, and it cost me 142,50 € (including delivery and taxes). I was a bit worried about some of the issues people were reporting. But for my use case this is perfect.

I am using this with my Macbook Pro, and Ollo X1 headphones (in a non-balanced headphone port). The headphones are ~32 ohm (101 dBSPL @ 1kHz RMS3dB @ 0 dBu), so very easy to drive. When I am using medium gain on ZH3, the volume I need to use with ZH3 is between 40-60 according to its display (with low gain 60-80) when the input signal from computer is at its maximum. I can go to 99 (medium gain), but while clean, it is too much to my ears for any longer than a few seconds (so I think I will settle with low gain with these headphones, though medium is fine too if you really need to go loud). It is nice that I can adjust volume either from ZH3 or from keyboard computer (the latter adjusts the USC II volume that I use for correcting the headphones and EQ, it comes with the Ollo headphones).

The remote works nicely, and I can even change songs from my computer by using it. So far I haven't felt this device getting hot. It is only slightly warm. Sound quality is all I can ask for. I also got the black extra "launch" knob. It is a nice sized device. Not too small but not too big either. Great for desktop, and also looks good. So one happy customer here. Currently I do not have use for XLR/analog out or other inputs than the USB. I haven't had any issues with the multifunction knob. It is intuitive and feeling is nice. Not super luxurious but for this segment it is nice, especially compared to small pots in many audio interfaces.

So if you have similar use case to mine, I don't see any reason to not check the ZH3, in case you need a headphones amp. I could drive these headphones quite fine even from the Macbook headphone port, but this gives nicer ergonomics, especially when I just need to connect a single cable to macbook to use it as a desktop (monitor acts as a hub where I have connected the ZH3).

 

[fws]

I think ZH3 actually looks a bit less impressive than some people make it.

Fosi ZH3 = 113dB SiNAD at 4Vrms (HP out), and 2.5W at 33Ohm (doesn't clip), Line Input (questionable input level/0.775Vrms)
Fiio K7 = 115dB SiNAD at 4Vrms (HP Out), 2.8W at 32Ohm (clips), Line Input (2Vrms)

However the K7 has also much more power into high impendance loads.
Fosi ZH3 = 273mW at 300Ohm
FiiO K7 = 500mW at 300Ohm

Rough values taken from Wolf's measurements at L7AudioLab
https://www.l7audiolab.com/f/fiio-k7/
Dashboard went up to 13.3Vrms with 107dB SiNAD

The only real advantages ZH3 have I can see are XLR Line Out, and perhaps the tone control. So unless those are required for someone, or the price is considerably lower than $200 of K7 ($160 for ZH3 as some reported certainly would make it viable), then I would just go for the true and tested FiiO K7.

For me the big issue would be the 0.775Vrms input, that is the line level standard found in some older days, if you look at Amirm's re-review of Behringer UM204HD, you will even find a hint it is 0.775Vrms design overdriven to output more as the performance drops sharply after ~0.780Vrms. If that is the input sensitivity of ZH3 then that is not just a bother, but a question - is that preamplified before being fed to the output stage or will the Headphone Out output power be reduced?

Imo that is a very important - what is the difference between internal USB DAC's and Line Input's power output and performance in ZH3?

 

[Whatsthephuss]

I think ZH3 actually looks a bit less impressive than some people make it.

I own the K7 and used it as my daily driver for almost two years. Now that I got the ZH3 I am giving the K7 away to a friend because I find the ZH3 to be an upgrade in every way.

FOSI is 113.4db SINAD AT 4V, while FIIO is 115db SINAD at 4.17V. I doubt anyone can hear the difference there… where I do hear a difference is the tone controls and the unclippable output. The K7 has rising distortion in the “extra output” that exceeds the ZH3, while the ZH3 stays low distortion no matter how hard I push it.

The tone controls themselves have made this my favorite headphone amp. I got the DX5II to compare the two and I will be keeping both as they both offer advantages. Being able to dial in the treble and bass quickly and easily from the FOSI has made listening to all of my headphones a pleasure, including HE6SE and AKG K340.

I’m currently listening to the RCA input from the DX5II feeding the ZH3 2.5Vrms and there is no clipping the input at all, and my ZERO 2 IEM sound great and loud on volume level 6. There is some noise as you approach volume level 32 for RCA in (the max output level is 32), but if you feed the ZH3 a strong input signal of 2V there is no problem amplifying even the most difficult to drive headphones far below level 32 output.

I got the FOSI ZH3 from their website for $160 including shipping, so I don’t see how the K7 competes anymore for $220. Thanks for the great review Amirm, ‘‘twas a great upgrade to my setup for less $$

 

[Whatsthephuss]

Another advantage of the ZH3 over the K7 I forgot to mention is the screen. Major kudos to FOSI for the auto-dark mode. And being able to switch back and forth between Headphone out (PO) and Aux with saved volume levels is a major plus over the K7 with its fixed volume wheel. My unit does not get hot but the outside temp here is only ~15C

 

[Whatsthephuss]

The only disappointment I have had with the ZH3 is finding out that the tone controls are bypassed for Line Output(LO) or AUX. I wonder if this is something that can be implemented in a firmware update?

 

[Whatsthephuss]

For me the big issue would be the 0.775Vrms input, that is the line level standard found in some older days

I couldn’t find where you got .775Vrms from? The specifications in the manual refer to RCA with 2V input. Perhaps this photo will help answer your questions,

it appears the RCA Input does not quite achieve the same output level as digital input.

 

[lucian]

I have massiv problems with the RCA analog inputs. Going from the DX3pro with 5m cable to the RCA inputs to the other side of the room I get massive his. Speakers are ADAMS connected with XLR.

If I connect the cable with the PAII at the same location of the fosi and same power plug (but going into passive speakers) - here is no hiss at all.