Aiyima A20

Is this Aiyima’s Best Amplifier Yet?

The Aiyima A20 uses Aiyima’s 10th anniversary style. It matches perfectly with the T20 tube amplifier to make a good-looking system. I believe there will be other products coming soon (like a new DAC) with similar designs. Overally, I think this is a great move from Aiyima.

Aiyima calls the A20 the “Masterpiece of the decade” and while that is definitely an exaggeration, I do think it is easily Aiyima’s best ever amplifier. And if you are in the market for a new amplifier for small and medium-sized systems, the A20 should definitely be on your list. So, I will hopefully show you why in this review.

Updated with the latest ASR measurements for more accuracy. See below for more details

So having listened to the A20 for a number of weeks now, I am very impressed both with its sound but also with its features, especially at this price point. Please read on to find out more.

Unboxing and First Impressions

The Aiyima A20 arrives in packaging that immediately communicates its premium 10th anniversary status:

The box design is elegant and professional, setting appropriate expectations for the product within:

Opening the box reveals the A20 nestled securely with protective packaging:

The presentation is impressive and befits Aiyima’s flagship amplifier offering.

Design and Build Quality

The A20’s design represents the pinnacle of Aiyima’s 10th anniversary aesthetic philosophy. The front panel is beautifully executed with clean lines and premium materials:

The volume control features attractive backlighting that adds both functionality and visual appeal:

Comprehensive Connectivity

The rear panel showcases the A20’s impressive array of connections:

The input options both XLR balanced and RCA unbalanced connectivity:

The input selector switch on the front makes it easy to switch between inputs:

For the RCA there is also a dedicated +3db boost switch::

There is a Volume Bypass: which enables the A20 to be used as a pure power amplifier when controlled by an external pre-amplifier or processor.

Advanced Features

The A20 includes sophisticated features rarely found at this price point.

The HPF (High Pass Filter) especially is a very welcome feature, and as you can see in the photo above you can control this frequency. What this provides is a clean way to blend a subwoofer into the overall response but allow speakers (like bookshelf speakers) to focus on the midrange and treble frequencies and not distort playing the lower frequencies.

You can toggle the HPF on and off via the front panel:

The HPF functionality is genuinely useful, not just a feature checkbox. When engaged, it allows the A20 to focus its power on midrange and treble frequencies while routing bass duties to a dedicated subwoofer via the SUB output. This configuration can significantly improve overall system performance, particularly with smaller main speakers.

Quality Speaker Connections

The binding posts are substantial, and well-constructed, accepting various termination methods:

The binding post quality and spacing demonstrate attention to detail and were first seen on the A07 Max I believe:

Premium Power Supply

The included GaN (Gallium Nitride) power adapter is a reasonable size for the power offered 48V 5A:

I believe Aiyima sell a 48V 10A power adapter as well, which will provide a little bit more power to the A20.

With up to 250W per channel into 4Ω loads (185W into 8Ω), the A20 provides substantial power reserves for even demanding speakers. More importantly, the amplifier maintains its composure and clarity even at higher listening levels, never sounding strained or compressed.

Ventilation and Build Details

The side grilles provide adequate ventilation while maintaining the clean aesthetic:

The underside shows access for screws needed when doing op-amp upgrades:

The A20 board is nicely designed, with a clean layout and plenty of space for larger op-amps:

12V Trigger System

Another nice feature is the 12V trigger, and Aiyima also included a cable for this trigger:

Sound Impressions

The Aiyima A20 delivers everything what you want from a modern class D amplifier, transparency, detail, control, and power, all while remaining completely neutral and uncolored in its presentation (unlike older non-PFFB implementations).

The TPA3255 PFFB (Post Filter Feedback) implementation in the A20 provides exceptional transparency. This isn’t an amplifier that imposes its own character on your music. The PFFB will force a linear transparent sound, it acts as a clean, powerful window into your source material. This matched with the power output gives you a level of detail retrieval is impressive, revealing subtle nuances in recordings that lesser amplifiers might obscure.

The amplifier’s neutral presentation makes it an ideal foundation for any audio system. Whether you’re listening to delicate acoustic performances or complex orchestral works, the A20 presents everything with equal clarity and precision.

It was interesting pairing this with Aiyima T20 tube pre-amplifier, and as I could route the audio either through the T20 (For ‘warmer’ tube sound):

Or optionally bypass the T20 for that clinical transparent sound:

Technical Specifications and Measurements

The A20’s specifications reflect its serious engineering approach:

Measurements

So for this section I have now added the recently published ASR measurements to the existing Aiyima published measurements adn as you will see they are roughly the same.

Aiyima own A20’s AP dashbaord shows a SINAD score of 95:

Independent ASR Measurements

[Audio Science Review that has now been published with comprehensive measurements] (https://www.audiosciencereview.com/forum/index.php?threads/aiyima-a20-stereo-2-1-amplifier-review.67502/) of the A20 using Audio Precision equipment, and I am pleased that the results confirm what I suspected, this is a fantastic amplifier and probably the best yet from Aiyima.

Below is a selection of the key findings, but I encourage everyone to read the full report linked above.

SINAD Performance: The measured SINAD is inline with the one Aiyima published at 93/94 SINAD:

Comparative Performance: In ASR’s measurement charts, the A20 positions itself impressively among its peers. It outperforms popular alternatives like the Fosi Audio V3 and WiiM Amp, confirming its status as one of the best-measuring budget class D amplifiers currently available:

Dynamic Range: The A20 achieves a fantastic dynamic range of 18.7 bits, which is exceptional for an amplifier at this price point. This means the amplifier can handle everything from the quietest passages to the loudest crescendos with ease, maintaining clarity and detail throughout the entire dynamic spectrum.

PFFB Implementation and Frequency Response: The only area of possible concern highlighted in these measurements was the PFFB (Post Filter Feedback) implementation in the A20 while good overall, it’s not quite perfect. There is some measured non-linearity in the treble frequencies when driving speakers with significant impedance swings. This is a known limitation of PFFB implementations and is not unique to the A20—it’s simply the physics of how these feedback systems interact with reactive loads.

In practice, with most real-world speakers, this minor deviation is unlikely to be audible, and the benefits of PFFB (reduced distortion and improved damping factor) far outweigh this small compromise.

Comparisons

vs. 3E Audio PFFB Amplifiers

The A20 compares remarkably well with 3E Audio’s more expensive PFFB amplifiers. While the 3E units may offer slight advantages in ultimate resolution and build quality, the A20 delivers 90% of the performance at a fraction of the cost. For most listeners and systems, the A20’s performance will be indistinguishable from much more expensive alternatives.

vs. Fosi Audio Recent Offerings

In terms of aesthetics, the A20 clearly outclasses recent Fosi Audio amplifiers. The 10th anniversary design philosophy creates a much more premium and cohesive appearance. Performance-wise, the A20’s TPA3255 PFFB implementation and comprehensive feature set give it clear advantages over most Fosi offerings in similar price ranges.

Rating

The A20 earns a 5-star pragmatic rating, as an excellent amplifier that represents outstanding value. The TPA3255 PFFB implementation, comprehensive connectivity, advanced features like HPF and volume bypass, and stunning 10th anniversary design make it a compelling choice for anyone seeking high-performance amplification.

Who Should Consider the A20:

• Anyone building a high-performance audio system on a budget
• Users wanting professional features like XLR inputs and HPF functionality
• Those seeking a clean, transparent amplifier foundation
• Listeners planning to add a tube pre-amplifier like the T20
• Anyone who values both performance and aesthetic appeal
• System builders wanting 2.1 configuration capability

Conclusion

While the A20 is not the “masterpiece of the decade” I think it is Aiyima’s Masterpiece, and it’s their best ever amplifier. Simply put, it sounds exceptional, has excellent features, and looks great for the price.

The A20 has many features that I like in class D amplifiers, the TPA3255 chipset with PFFB, the XLR and RCA inputs, HPF, subwoofer output, volume bypass, and trigger operation.

This is everything you want in an exceptionally good amplifier.