Very nice review!

Is the Onyx susceptible to EMI? I am looking for a pocket-friendly dac/amp that is resistant to EMI static.

@H T T
I haven't noticed any EMI interference but didn't use it stacked inside my pocket.
I have only used it hanging out from my phone.
I will test it for you with the Onyx body touching the back of my phone and report back.

@H T T
OK , I have been listening for an hour now with the Onyx connected to my phone and kept at the back of it with my hand.
Streaming Qobuz through 4g+ and the Onyx is dead silent.
Not the slightest interference.
Phone is Xiaomi Note 9 pro.

Thank you for testing it out. I will likely purchase the Onyx later in the summer. My wallet needs to recover from my recent Prime Day purchases.

You won't regret it , unless something better surfaces out!!

I hope you don’t mind another question. How does the Onyx compare to the FiiO Q3 as both are, in effect, THX certified? The Q3 looks to be a better value.

@H T T

Not a fair comparison due to different form factor.
HD660s - THX Onyx
HD660s - FiiO Q3 balanced

More power for the Q3 and better control , fuller , more dynamic
Better power supply = more silent although the Onyx is as good as it gets for non battery device.
Onyx = more luminous , not brighter , a touch more detailed and fully extended
But Q3 resolving with finer quality but slightly treble rolled off
Q3 = more organic and analogue sounding , sounds more cohesive , Onyx = more detached
Q3 = better volume control thanks for the potentiometer
Q3= wider and expanded soundstage
Q3=bass boost , two gains , two filters
Differences are quite minimal and both sound great.
It is the form factor that someone should consider before buying.
If you are OK with the size and battery charging , and can invest in balanced cables then the Q3 it is.

Thanks so much!

Hi,
Where did you find the info about "Tidal has rolled out an update that supports full MQA decoding on Android with the Onyx as a DAC"?
And could you already test the feature?

@Sma0815
Hi , the Tidal update was sent to me prior to release so I can test it with Onyx.
Now it is officially updated and I get full MQA decoding with the Onyx.
Three led lit as magenta.

Hi,

Thanks for the great article. Do you know how this compares to the Astell & Kern PEE51 usbc DAC?

Hello thank very much for liking it.
Unfortunately I don't have this DAC.

My v30 said bye bye and my ifi portables are to big for everyday use on the go.
So because of yout amazing review i know it will work with 660s and others but can it drive Sundara ? Not on high levels but good enough ?
I need a usb dac amp to use with my sony xperia phone

@Tripokaridos
Thank you.
For a USB powered dongle it does very good job with the Sundara.
Of course you know that it is a current hungry headphone but for on the go use it is great.

Great thanks i had some thoughts but u solved everything.
Just order it.
The single ended power and portability is.amazing .

Really happy with mine. Especially the flexible cord…..easy to double over and fit it in my pocket. Used with LG40 and iPhone mini 13 (and Dunu SA6, Moondrop Blessing, Senn 58X and Focal Celestee)

I am still using it as my reference USB dongle.
It is very good.

I take your advice Review and i have it in my hands now...
First impressions WOW this sounds good they can drive Sundara very good on low to medium volume levels, HD650 600 and 660 very easy loud levels.
I like the build quality and that is just one part all together without pop in and out cables.
Also i like that when i take off my headphone it goes on standby.
Nice thank U Ichos for another great recommendition.

Thank you, I am glad that you liked it.
This means a lot to me about what I am writing in the reviews.

Can i ask ? I feel like connection with pc is more powerful than my sony xperia mobile phone. Is there any android app or something that i have to change on android ? Does it have automatic gain ?