Topping A50S Review – Prodigy

Pros –
Solid build quality, Small footprint but feels planted on desk, Ultra-linear sound, Coherent presentation, Great soundstage width
Cons –
Small volume knob, No negative gain setting for IEMs, Could do with greater dynamics and soundstage depth
Verdict –
The A50s remains an easy recommendation for its well-rounded design, ultra clean and linear sound and very reasonable price.
Introduction –
Topping always stood out for the strong value to performance offered by their products. However, the same can be said for many sources these days. The pursuit of market dominance led to the production of their own in-house NFCA (Nested-Feedback Composite Amplifier) chipset that has topped the charts for SNR since. Indeed, that means besting THX’s cutting edge chips and some infinitesimally pricier models too. Topping took this one step further when they revealed that their NFCA technology would not only reside in the flagship A90, but their cheaper models too. The entry-level L30 blazed the trail, offering the same superlative objective performance with cut-down features and build to suit its lower price point. The A50s is Topping’s latest effort, implementing the same amp chip while introducing a substantially more premium build and design in addition to balanced output. Though it is not a true balanced amplifier, possessing only single-ended inputs, the A50s looks to be the versatile middle-child in the line-up that offers the strongest bang for buck.
The A50s retails for $199 USD. You can read more about the A50s and treat yourself to a unit on Apos Audio. For objective breakdown, please see amirm’s review catalogue on Audio Science Review.
Disclaimer –
I would like to thank John from Apos Audio very much for his quick communication and for providing me with the A50s for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the amplifier free of cost, I will attempt to be as objective as possible in my evaluation.
Contents –
- Page 1: Intro, Unboxing, Design
- Page 2: Sound Breakdown
- Page 3: Comparisons & Verdict
Specifications –
- 4.4mm Balanced Output
- 0dB and 6dB Step Gain Setting
- <0.00007% THD + N
- 144dB DNR
- <0.3uVrms Noise
- <0.1 Ohm Output Impedance
- 3.5W x 2 Max Output Power
Unboxing –

The Topping A50s comes in a small box safely enclosed within laser cut foam. Removing the lid reveals warranty papers and the manual with the amp below. Underneath is a cutout containing the 15v power supply, plug attachment that varies by region and a 1/4′ to 3.5mm adaptor. It’s a simple and sufficient setup that will serve the majority of users.
Design –
Buyers will find a very similar experience to other Topping devices and, in terms of construction, a healthy step up from the cheaper L30 leaning more towards the premium A90. There’s immediately a lot more heft in the hand than the L30 as the build is all aluminium with single-piece top and sides that gives the impression of a uni-body construction. That said, there is a lid panel and screws though they have been relocated to the bottom for a cleaner look. In addition, the switch-based interface has been exchanged for a single MFB control scheme for an altogether more handsome and streamlined design. The rear houses two RCA inputs and 2 RCA outputs for preamp functionality. This means the A50S is not a true balanced design as there are no balanced inputs. Meanwhile, the front sees the MFB button, ¼’ TRS output and 4.4mm balanced output in addition to a volume pot.

The A50S sports an exceptionally small footprint, being shorter and just a little wider than the already compact L30. In return, some compromises have been made, there are no XLR inputs or outputs, the single button means there is more delay when changing between settings and also more chance of accidental presses as opposed to the switch based A90 and L30. Similarly, the volume knob, though smooth and well-weighted, is especially small which makes it difficult to manipulate, especially when the 4.4mm port is in use. That said, this makes the A50S ideal for space-constrained users who still want the flexibility offered by balanced output and the added weight means it feels nicely planted during daily use. I am very enthusiastic about the build quality and aesthetic design on offer.
Usability –
Setup is simple as with basically any other amplifier, simply connect inputs from your DAC via RCA and speakers to the pre-out should you desire. The included power adaptor is of the linear variety that offer a faster transient response and lower noise output than traditional switching power supplies. I appreciate just how compact the wall wart is, dwarfed by most competitors. Though best practice would be to give your audio equipment their own outlet, those constrained to using a power board will have a good experience here as a result. In addition, it has a removable plug which means the power connector can be swapped to suit other regions. The amp itself is a breeze to use. Tapping the power button on the front powers on the device and the front-facing status LEDs illuminate to denote the gain setting with further clicks toggling between the two. Holding down the button for around 2 seconds powers the device off. The A50S remembers the last used setting which simplifies use. It should be noted that there are only two gain settings, 0/6dB on the SE output or 6/12dB on the balanced out. This means volume range for sensitive in-ears is reduced relative to the cheaper L30 that offers a third -9dB gain setting.
Otherwise, the amp is easily stacked with four grippy rubber feet on the base that are wider than those on the L30. This gives it greater stability on the tabletop in conjunction with its added weight when plugging and unplugging attached gear. As with the L30, I found the A50s to become warm to the touch over hours of use but never hot or alarming. There is similarly a second delay when switching from headphones to preamp and the volume pot controls the pre-out too which adds to its versatility. I heard no pops or other noises when plugging/unplugging in-ears and similarly, no noise when the amp was powered on or off with in-ears connected. It is overall a high-quality piece of hardware with a straight-forward user experience though small niggles like the small volume knob and lack of negative gain are strange to see coming from the cheaper L30 that suffered from none of these issues.