AUNE X7S Class A Balanced Headphone Amplifier

Hello all,
I am starting this topic in order to share thoughts about this beautiful, capable and affordable class A balanced headphone amp.
I bought this amp a few months ago when I watched the Z reviews video and was on sale for 190 euros at a local store.
When I bought it I have in mind to drive a planar magnetic headphone and I was searching for a well build and relatively cheap amp. After trying some low impedance planar cans and some around 50-80 ohm through 1/4 output, I was not quite happy and I was about to return it. Until I listened it with the 300ohm Sennheisers… Then it was that thing shined really. After making a little research why this was happening I found out about the term ‘‘output impedance’’ and how important this is to a headphone amplifier. Considering that this amp has an output impedance around 11 ohms it was kind of expected to match well with the higher impedance cans (As per NwAvGuy Blog ; THE 1/8th RULE: To minimize all three of the above problems, it’s only necessary to keep the output impedance less than 1/8th the headphone impedance. Or, put another way, just divide the headphone impedance by 8 to get the maximum output impedance without potential audible degradation).
The balanced output vs 1/4 is day and night in terms not only power but also soundstage openness and body. Noticed also at 1/4 a roundness to the highs which was very annoying to listen (not extended highs).
The amplifier has also variable RCA pre outs at the back to run studio monitors which are not selectable and outputs along with the headphone output. Running my Yamaha HS8 from this, I noticed the class A ‘‘fullness’’ but I would not recommend it because the sound character of the rolled off 1/4 in front is following the pre outs as well.
So as from my experience in general a conclusion:

  • Highly recommended for 300ohm headphones
  • Be careful your DAC (or source) output to be not lower than 2volts in order to have the full power potential
  • The amp gives the 100% at XLR balanced output
  • The headphone output of my RME DAC is clean and perfect but AUNE class A adds something more that is so enjoyable to listen to :slight_smile:

I would like to hear the thoughts of any proud owners too!

AUNE X7S review Z Reviews


I am really looking forward to buy this amp as an upgrade from the SMSL sAp II Pro. I want to pair it with my Hifiman HE-400 with a balanced cable.

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I got Aune X7S together with X1S as a bundle from massdrop (or drop now) some time ago to run affordable balanced for HD58x. It is my first real headphone amp (my first attempt at audio :slight_smile: ) so I cannot compare them to anything yet, though I have been greatly enjoying my HD58x balanced.
My only concern is X7S does get warm being class A.

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Sounds like a very good setup :slight_smile: Class A has its magic and is worthing a little heat like the tubes do :smiley:

I have this amp for almost a year. Around a month into its use something happened to the power supply for reasons unknown and the amp started to hum. Hum would start as soon as I turn the amp on, with or without any input. So, I decided to change/upgrade the power supply to AUNE XP1 External Linear Power Supply. After that everything went great until last week, when I turned on the amp and heard that same cursed hum. It comes and goes and I down know what causes it.
Has anyone encountered this issue?

Hello, this is bad indeed… What type of headphones are you using? This hum comes both in balanced and 1/4 jack? RCA cables maybe? Also at the bottom at which position are the gain switches?

1/4’’ - DT 1990 Pro, Argon Mk3; XLR - HD6xx. Mid gain. When I plug in Argon I practically can’t hear it, but on other headphones hum is very distinct.
I haven’t tried doing anything with RCA cables. I’ll do more testing on the weekends.

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This is just a longshot, but try to have 2 different power outlets and therefor not use the common ground in just one outlet.

Hum to me is a ground problem in some sort.
Just be sure to see that the outlets not are on the same fuse in the stopper cabinet.

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UPDATE: After some testing during the weekend I came to a conclusion that the hum might have been a result of some power grid malfunction or something of the sort. It is gone for now. Just in case I changed RCA cables.

Coming back to the topic of the amp itself – it is magnificent)
Every time I listen to the Portal from Avengers: Endgame OST I feel the presence of sound gods!

I have one question though – I use SMSL Sanskrit 6 as my DAC. Should I upgrade? (if yes what would you recommend?)

Hopefully the hum will be dead forever… I had the dragonfly black and I upgraded to RME ADI-2 dac. There was a difference but not a 900 euro difference. I could live very happily with the dragonfly black. The thing is that if you are ok with your setup, I doubt if you will get back your money in sound, upgrading the dac portion. I bought the RME because I wanted the headphone output to drive some planars at the future and the ability to control my active monitors driving both them and the AUNE amp without changing wires etc. If you are curious though, you can go to a local store and experiment yourself and make your own conclusion :slight_smile: For example you can try the other Aune module X1S or dragonfly Red which are at the league above yours…

Thanks for the recommendations! It so happens that I already own Dragonfly Red. I use it at work. I was looking at SMSL SU-8 as an upgrade. From what I have read/watched it is a good DAC for the money and it is balanced. I still have my eye on THX AAA 789 and with SU-8 I would be able to use them both.

This would be for sure an upgrade :slight_smile: If you leave in US you are so lucky to shop from mass drop… Living in EU you are paying so much more from the actual cost, makes things complicated a bit…

Another happy owner here :wink:

Two years ago I decided to finally make the step into the desktop audio world and upgrade from my portable gear (Beyerdynamic DT1350 with Clip+/FiiO E11) - influenced by Zeos I bought Aune X1s DAC/Amp and after few months added the AKG K712 Pro. A year back I got the Aune X7s so running the 712’s from this stack.

I don’t have any comparison with other devices, but I’m happy with what I have and what I hear :slight_smile:
Currently I’m waiting for my local shop to get the 6th gen Aune X5s in stock (desktop digital player) so I will bypass the laptop usage for music listening and have plug&play desktop solution for pure music enjoyment.

Btw. does anyone using the alternative/better power supply Aune XP1? Does it improve the sound?

Don’t be concerned about the physical warmth it is an amazing amp it’s class A so it will get warm, and the x1s is an uhhhmazing DAC! Keep them forever!

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The Aune X1s and X7s is permanently plugged into my TV for my gaming needs via optical.

Anyone have a clue what improvements the 2021 edition of the X7S has?

They changed the psu, now is powered with a dc power supply

Aha, that makes things a lot simpler in finding alternate power supplies.
The Aune Europe site does not show any useful info.

I kinda want to get this amp but I don’t see any specs for output impedance and if it’s still 10 Ohms I’ll get something else.

It is 10 ohm. ASR measured 11.1