The new Topping A90 is a $499 ‘Ultra High Performance’ desktop headphone amplifier and pre-amplifier. It joins the D90 DAC (which Linus recently reviewed here) to complete Topping’s flagship headphone range.
Disclaimer: Topping sent a sample of the A90 to Headfonia to evaluate and share with our readers. As always, our thoughts and conclusions are our own.
“TOPPING is the top.” – Topping.
While this explanation on their company profile page is both succinct AND enthusiastic, Chinese manufacturer Topping certainly is enjoying a rise in prominence of late among audio enthusiasts. Whilst they initially gained notice chiefly for delivering exceptional value to budget-conscious punters; lately, they’ve been taking names when it comes to delivering levels of performance that have no doubt made established industry players take note and pay additional heed to their own objective performance.
Performance: a numbers game.
Just on that last point for a moment – there has been a sweeping wave of ‘objectivism’ wash through the industry in the past couple of years and has been driven by a couple of factors. Firstly, there’s been a lot of focus put on the measurements of amplifiers and DACs, and there’s subsequently been an arms race of sorts with manufacturers seeking to achieve greater power, lower distortion, and higher dynamic range (among other attributes). And frankly, you – the end customer – is the ultimate winner here.
The other factor that’s been partly responsible for this numbers-driven philosophy has been the abundant availability of previously unavailable technology, take for example THX amplification. Manufacturers have taken THX’s licensed Achromatic Audio Amplifier technology and have utilised it to great effect, two prime examples being Drop’s THX AAA 789 headphone amplifier, and SMSL’s SP200 THX 888 which I reviewed earlier this year. While putting the diminutive $289 SMSL amp through its paces, it did dawn on me that we might nearly be at the point where headphone amplification is, for lack of a better term, a solved problem. When distortion is inaudible, and music is played back at the proper frequency at the dynamic range at which it was mastered, can we call it a day?
Well, it seems we can’t, and that’s largely thanks to objectivity’s more unpredictable counterpart, good-old personal preference. While dead-neutral isn’t everyone’s’ audio cup-of-tea, we all have our own individual system, headphone, and pairing considerations that require different amplifier features, capabilities, and design. So then, there really can’t be a ‘perfect’ headphone amplifier. Right?
Enter the A90.
Well, it seems that the good people at Topping have certainly made an earnest tilt at what seems, on paper, to be a pretty ‘perfect’ kinda headphone amplifier: the new $499 A90. Or, to give it its full name, the A90 ‘Ultra-High Performance Headphone Amplifier’ (let’s just go with ‘A90’ from here, ok?). I’m going to throw in an early spoiler here: it performs astonishingly well, as its credentials would suggest, and is utterly competent when it comes to amplifying headphones. But will it work on your desktop, with your gear? Well, we’d better take a closer look.
So what is it? The A90 is a full-sized desktop headphone amplifier and preamplifier, with fully-balanced circuitry. It allows users to connect headphones via more traditional 4-pin XLR and 6.3mm single-ended connections, as well as the newer 4.4mm Pentaconn connector which is becoming embraced more and more widely by global manufacturers. IEM users might bemoan the lack of a 2.5mm balanced or 3.5mm single-ended connection, but Topping’s choice of 4.4mm Pentaconn is a statement of intent that the A90 is intended to be a future-facing piece of equipment, and also one that the owner can hang onto for a long, long, time in terms of its power and versatility.
Speaking of power, Topping has squeezed a shed-load of it into the A90. It’s capable of a whopping 7.6 Watts of power into 16-ohms through either of its balanced connections and still manages to eke-out a whole Watt when driving a higher impedance 300-ohm load. The A90’s is no slouch in terms of its single-ended performance, being capable of a healthy 2 Watts at the usual 32-ohm benchmark. Topping has achieved this not by leveraging THX technology, but by developing their own Nested Feedback Composite Amplifier (NFCA) technology, which utilises a voltage-current hybrid feedback architecture and helps in achieving its starkly impressive dynamic range of 145dB. Total Harmonic Distortion is almost comically low, at <0.00007% when pushing 500mW at 32-ohms.
Topping has included a High/Medium/Low three-way gain switch on the front panel of the A90, allowing owners to opt between gain as low as -9.5dB and as high as 15.5dB, depending on the combination of single-ended and balanced inputs and outputs used. Coupled with a very low noise floor (0.2uVrms) plus an output impedance of less than ) 0.1-ohms, this should (on paper) allow the A90 to give usable volume control over sensitive IEMs, as well as hard-to-driver full-sized headphones without any undue changing to their frequency response – definitely something for me to put to the test.
The back panel of the A90 reveals both XLR and RCA input connections, plus matching balanced and single-ended pre-amp outputs. By toggling the RCA/XLR switch on the front, the user can switch between two different inputs sources (so long as one is balanced, and the other single-ended), and Topping has also made the A90 switchable between Pre-out and Headphone Amplifier modes via the standby switch on the front – they can’t operate at the same time, so bad luck if you had visions of listening to open-backed headphones with a subwoofer at the same time (I *might* have done this in the past). I find this to be a much neater solution than automatically muting the pre-out circuits when headphones are inserted, such as on most Schiit Audio headphone amplifiers. The A90’s pre-amp capability gives it a headstart over the aforementioned THX amps as it can perform double duties when paired with an upstream source, like a DAC or turntable, and a downstream with a power amplifier or powered monitors.
Head over to page 2 to read more about the A90’s build quality, and user experience.