In the custom of (most) small form factor budget power amplifiers, the BT20A takes the form of a black box. It’s clean and simple in design and can easily blend in with other components in your system or be tucked away in a corner.
It feels solidly built and has an anodized matte surface. Weighing in at only700g, it’s super easy to position or move around. The finish is surprisingly good for a budget amp; the BT20A has rounded edges and clean aesthetics.
Situated on the front panel is the power switch, accompanied by separate treble, bass and volume control knobs. The situation on the rear panel is similarly simple: here you’ll find an RCA input, passive speakers output, Bluetooth antenna and the DC power jack. I was pleased to discover that the power LED on the front of the unit is nice and dim so it’s not distracting.
The BT20A can receive audio via either its RCA Line in or Bluetooth. The Bluetooth receiver is limited to SBC and AAC codecs but testing with my iPhone the audio quality was more than acceptable.
How does this little budget amplifier perform? Pretty well it turns out. This tiny guy has a lot of power on tap and it can easily drive most bookshelf speakers with ease. Sure, its measurements aren’t anything to write home about but they’re perfectly acceptable for the price.
The tone controls work well and let you colour the sound to your liking. It should be noted that the treble and bass dials on my unit were turned all the way down out of the box. I’d suggest moving them both to 12 o’clock before playing any music (in the default position, the sound was muddy and muted).
Take a moment to tweak the treble and bass controls once you’ve fired up some music. I found that right in the middle on both the treble and bass works best for me but it will depend on your speakers and your individual preference.
The little BT20A had no trouble powering my NHT C3 speakers and had heaps of power to spare. As a result, the bass was full-bodied and tight (even with the tone set to neutral), the midrange was clear and the treble lively and detailed.
The BT20A sounds energetic and dynamic. It takes the polyrhythmic beat of The Pineapple Thief’s “Alone at Sea” and shows it has a good sense of rhythm. The details and resolution are good, the vocals are engaging and the overall performance is better than I had expected from this tiny black box.
Of course, it doesn’t sound as muscular or insightful as a higher-tier product or quite as organic as a good Class-A amplifier but I think it sounds great relative to its low price. Playing through Carbon Based Lifeforms’ “Interloper”, my speakers were filling the room with rich yet tight bass and the synthesizers were swooping around me in all directions.
The Fosi Audio BT20A is ideal for anyone looking for a small and affordable speaker amplifier. As long as you’re expectations are realistic, there’s little chance of being disappointed. If you need an amp for a budget or secondary system and don’t want to spend a bundle, the BT20A is the perfect solution. At this price, you couldn’t ask for more.