Topping A90 Review

Topping A90 headphone amplifier

Performance and Sound Quality




I was keen to look at the A90 through the lens of the would-be customer who might be considering purchasing the A90 as a ‘do-all’ headphone amplifier, capable of powering all different kinds of headphones. And, there’s no point being able to power something with authority if you ain’t feeling the music – I’m holding the A90 up to very high standards indeed. I’ve been super-impressed by two solid-state headphone amplifiers already this year: the $289 SMSL SP200 THX AAA, and the $199 Schiit Asgard 3. In fact, they both made it to our Recommended Amplifier list. With this in mind, the A90 would need to impress sonically, as well as prove its quality and versatility to earn a ‘nod’ over these two amps which are $210 and $300 cheaper respectively. 

It can be a little intangible when trying to impart the nominal differences between the sonic qualities of excellently implemented solid-state amplifiers, but the Topping A90 impresses immediately straight out of the box. In terms of its sonic characteristic, the A90 an utterly transparent, dynamic, and uncoloured presentation. Using my Sennheiser HD600’s which are both honest to a fault in terms of neutrality, as well as highly revealing of an amplifier’s characteristics (both good and bad), the A90 steps right-up and grips your music by the ears. Staging is wide-open, and there isn’t a hint of compression. The bass in Tool’s ‘Invincible’ is felt rather than simply heard – it’s taut, tight, and bloody enjoyable on the HD600’s, which can tend to turn flaccid without proper powering. Danny’s snare and tom hits land with dynamic authority, and Adam’s chugging guitar crunch is vivid and utterly electrifying. 

It’s terrific to have the ability to use the A90’s fully balanced configuration, utilising the superior noise-rejection of XLR cables (especially over long cable runs), and to take full advantage of the A90’s power via the balanced headphone outs. However, the A90 also happened to perform perfectly-well with both single-ended inputs via the RCA-in, and via the single-ended headphone-out when tested. The A90 is a terrific-match with its much smaller and more affordable digital cousin, the $129 USD E30 DAC which received a thumbs-up from yours truly earlier this year. If you’re on a firm budget and you have harder-to-drive headphones, or need a dedicated pre-amp in your set-up but still require a capable digital decoder, then the A90/E30 is a superbly-capable $628 stack.

Topping A90 headphone amplifier, Topping E30 DAC and Sennheiser HD600

Topping A90 headphone amplifier, Topping E30 DAC and Sennheiser HD600

The A90 presents no hint of peak or dip at any frequency – it’s an absolutely achromatic playback experience, yet it isn’t at all devoid of musical enjoyment. Some cheaper solid-state amplifiers can tend to add a sense of ‘glare’ or sterileness to the treble department, but nope – nothing to report here. I had similar feelings when assessing the SMSL SP200 – after a while, you realise you’re simply able to describe the nuances of your headphones themselves. The Topping A90 provides a flawless peek into all the details of a piece of music, good or bad. If it’s there, it will reveal it. If the transducers of your headphones are capable of reproducing it, it’ll do it for them. 


Versus my usual desktop amplifier, the Questsyle CMA600i, the A90 was nigh-impossible to tell apart in a back-to-back comparison. Very close listening revealed a shade more treble energy above10kHz in the Topping, which was akin to a mild layer of haze being blown away from the Questyle’s top-end. The CMA600i does have a DAC built-in and is much more substantially built and packaged. But, it was both much more expensive when it was built, and no longer available for sale so it’s not an entirely apples-for-apples comparison. But, the fact that the A90 can play in its ballpark says something about its capabilities. 

The Schiit Asgard 3 had a slightly coloured presentation compared to the Topping, with a slight forwardness in the presence region combined with a slightly more congested treble region, without the same sense of ‘air’ as the A90. Now, while the Schiit is considerably more affordable than the A90, it is also only a single-ended unit with the one 6.3mm output. That might be the only connection you need, and if simplicity is your goal, then it may well be for you. However, the A90 is a more versatile all-rounder in terms of its balanced inputs/outputs, and it does present a more vivid, neutral picture than the slightly coloured Asgard 3, which has a more laid-back presentation by comparison. I must note that the Asgard does run quite hot during operation whereas the A90 barely warms up at all, so that might be of consideration when planning a desktop stack/configuration. 

Sonically the A90 is line-ball with the SMSL SP200 THX 888, to my ears at least, when volume-matched and played back-to-back. While the SP200 features XLR inputs and a 4-pin headphone output, it’s not a truly balanced topology – these facilities are for convenience only. The SMSL also eschews pre-amplifier functionality to deliver a more bare-bones product. If you’re on a tight budget and $210 difference could be better spent on headphones, than the SP200 will happily give you perfect solid-state headphone performance. But, if you’re likely to upgrade headphones, or like the idea of using it as a preamp, or as part of a fully balanced system than the A90 is certainly worth the upgrade. I think it’s definitely worth it for the upgrade in finish and quality alone – the SP200 feels toy-like when sitting next door to the A90.

Headphone testing

Sensitive IEMs: Craft Ears Craft FOUR.  

With multiple gain settings and an incredibly-low advertised noise floor, how does the A90 handle sensitive IEMs? Switching the A90’s gain to ‘Low’ and turning the volume down to zero, I plugged in the 10-ohm Polish CIEMs via a 2.5mm to XLR adapter, and didn’t hear so much as a hint of noise. In fact, I had to turn the volume dial up to about 3pm on high-gain before I started to hear the faintest whisper of a noise-floor (with my hand well and truly away from the ‘play’ button…). Back on low gain, I popped-on a CD of Radiohead’s Hail to the Thief from my Nakamichi MB-8 CD-player, and did notice that volume was slightly audible with the volume set to zero. Slowly turning it up, there was a slight patch of volume imbalance before reaching ‘loud enough’ at around 8:30 on the volume pot. Swapping-out the Craft FOUR for the new Final A8000 (keep an eye out for a review around here in the near future!), the less-sensitive flagship universal IEMs from the Japanese manufacturer turned-out to be far more usable on low-gain on the A90, with plenty of usable volume control and less problematic imbalance at the lowest setting.

In short, the A90 is definitely a viable option for IEM users. But, if they are your primary source of sound then you may need to consider either an impedance-raising adapter or perhaps another amplifier altogether if you have more sensitive IEMs.

Head over to page 4 to read more about the A90’s performance.

4.2/5 - (88 votes)


Hailing from Sydney's eastern beaches, Matty runs his own beer business, 'Bowlo Draught', as well as working in creative advertising. When he's not enjoying his hifi and vinyl collection at home, he can probably be found rolling-up on the green at his beloved Bondi Bowling Club.


  • Reply July 6, 2020


    last test comment

    • Reply June 15, 2021


      I currently have a drop 789 and with my high end dac and hd800s have reached the best sound I have ever heard.

      That said I’ve read that the 789 will compress the music and the A70 would be a far better choice. I’m setting up sereral systems around the house with a less expensive DAC. So getting another amp is in the planning.

      Would I be improving my main system by replacing the AAA 789 with the A90?

      I have asked the drop boards this and mostly got back less than useful information from people who have clearly not compared the two.

      If the sound would not be much different using HD 800s headphones, I could save one or two hundred dollars on the computer setup. Not a lot but it would be a proven divise. If it will notably improve the sound, or slightly above notably improved, it would be worth the upgrade.

      Thanks in advance.

      • Reply June 16, 2021


        You probably won’t hear a substantial difference. The A90 has the benefit of a fully balanced topology, plus balanced preamp facilities and 4.4mm output though.

  • Reply July 6, 2020

    Carl A

    Really good review, many thanks.
    Some great comparisons with different headphones.
    Can I ask what those aftermarket pads are that you are using with your Sine dx?
    Be well.

  • Reply July 7, 2020


    How do you feel about the Topping D90/A90 versus Burson Conductor 3x??? I know that 3x has the double price of D90/A90 combo, but can the Topping combo nearly reach the level of Burson? Thank you very much.

    • Reply July 8, 2020

      Matty Graham

      Tough call without comparing them back-to-back. I loved the single-ended Conductor 3, ultimately it would come down to your budget and sense of aesthetics/form-factor preference. The 3X is hard to beat as an all-in-one unit.

      • Reply July 8, 2020


        Thank you very much. I have a chance to take the used 3x as the same price of new D90/A90 combo, for that reason I really want to compare both of them. The 3x receives lots of good reviews from many audiophiles. However, D90/A90 reach the highest measurement from Audio Science Review community. That’s make me wonder should I swap for the D90/A90 combo. For my main gear, I use JBL 305P powered speaker (3x acts at a DAC/Preamp), and HD660S.

  • Reply July 7, 2020


    ultra high performance for $499? Come on, be serious 🙂

    • Reply July 8, 2020

      Matty Graham

      I would genuinely caution anyone arriving new to the hobby that price = performance (unless that’s a sarcastic emoji?). It’s a good time to be a consumer in this hobby right now with budget gear performing as strongly as this does.

  • Reply July 8, 2020


    Matty, I am curious as you have reviewed both the FA-10 and A90 what your feelings between the 2 are?

    • Reply July 9, 2020

      Matty Graham

      Hi Ben, I personally haven’t listened to the FA-10 so I can’t give you a direct comparison. Linus reviewed it favourably, so it’s definitely also a very good amplifier. It’s a bit larger and a bit more expensive, so if a stepped attenuator and even more power (16 watts @ 32-ohms) are are important for you then it might be worth considering.

    • Reply July 19, 2020


      I have both A90 and FA-10 while using D90 as my DAC. I love A90 over the FA-10. The A90 is transparent, powerful (can drive my Susvara easily) and extremely enjoyable to listen to. FA-10 is a colored sound, not as transparent, Mid-bass is boosted and midrange is made to sound meatier but not acurate. You can tell if you listen to the songs that you have listen for long period of time and also listen to the recorded voices of your friends and family. The treble has more detail on A90 with crisper leading and trail edges where FA-10 has smoother treble. I prefer A90 over the FA-10 for my headphone listening experience. It is not easy to beat A90.

  • Reply July 19, 2020


    Hi. Guys, this is really the big question is Flux Lab FA-10 or 12 better? Timbre, slam, details. People are raving about it, high end for mid – fi price and we need answers!
    Somebody help please! 🙂

  • Reply August 30, 2020


    Nice review and glad too see this site still running strong returning to after so many years👌

    Question tough;
    I am looking for a step up from my old jds element for my LCD2 (pre faz). And I’m going back/forth between the a90 and LP HPA RS02/08. Which one would u recommend?

    • Reply August 31, 2020

      Matty Graham

      Thanks for reading Mel!

      I’ve not had the chance to hear the Lake People set-up so I couldn’t give you a good comparison. I can say with confidence that the A90 will give you ample power and performance with the LCD2, and likely for anything else that you decide to pick-up down the track. What are you using as your source?

  • Reply August 31, 2020


    Hi Matty thank u for the reply!!! The only source I have now is my labtop and the element😁, but Im definitly be going to get a dac. Thinking about the d90 offcourse, but im open for suggestions.

  • Reply October 12, 2020


    Hi! I have a Chord Mojo a AKG K701 and a Sennheiser HD660S.
    The A90 pairs well with the Mojo?And with the K701 and HD660S?
    Thanks for your review;)

    • Reply October 13, 2020


      Hi Edu, if you’re looking to add a little more power to your set-up the Mojo ought to work perfectly as a DAC upstream of the the A90 when set to line-out mode. It has more than enough power for both the K701 and the HD660s and ought to provide a completely neutral signature to both.

  • Reply December 9, 2020


    Hi- how does this A90 compare to Sabaj D5 or SMSL ?

    • Reply December 14, 2020

      Matty Graham

      I haven’t listened to the Sabaj, but the Topping is more of a ‘purist’ analogue device and is also more powerful. Do you have a particular ‘SMSL’ in mind?

  • Reply December 25, 2020


    I notice not many reviewers focus on “chip” vs discrete amps. The A90 sounds great as an op-amp example (which I think is it’s topology). Do you feel it suffers from dry and 2-D “chip” sound? And spending $1000+ on a decent entry/mid level fully discrete topology with decent transistors would add reality, depth, and tone, and be worth consideration?

    • Reply December 25, 2020


      (and, ito of sound, not features, do you feel it differs much from the THX789? I find that tech to be impressive, netural, transparent, great detail, but still “flat” and “dry” compared to well-implemented discrete or tubes, and also a little fatiguing for long listening in the treble energy. I’ve heard some reviewers say the A90 is like the THX but a little more “musical” or “organic” – would you agree?)

  • Reply April 14, 2021


    Hi Matty,

    Thanks for a great review. Do you know if there would be big difference between A90 + D90 vs Topping DX7 Pro ?

    Thanks in advance

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