Fosi BT20A Review – A Budget Amp With A Budget Sound

Have you been shopping for a cheap amplifier and been tempted to purchase the Fosi BT20A for just $80, but not sure if it will work well with your stereo set up or sound well enough to enjoy your music?

NOTE: Click here if you are interested in my review of the new BT20A Pro.

Are you someone who has been listening to hifi products for many years and have been tempted to buy this little amp in order to hear how it sounds compared to your more expensive gear?

Well, I’ve spent the last month listening to this amp and have really wrestled with how to present this review as I think this amp might work for some people and others might find it rather boring.

In this article, I want to quickly review the specs of this amp and tell you about some of the pros and cons of owning one. Then I’ll explain to you my thoughts on the overall sound of the unit and I’ll also explain how I found Fosi Audio’s slogan of “Hifi Made Fun” kind of ironic.

Let’s get started by looking at the specs on the Fosi BT20A next…

Fosi BT20A SPECS

The Fosi BT20A is a small, class D amplifier, made in China, that normally retails for $89.99, but is currently on sale via Amazon for just $79.99.

This is an amplifier only, allowing you to hook up one audio source, like a preamp, CD player, or DAC with the ability to also stream music via bluetooth connectivity. There is no phono stage included so you will need an external phono preamp or a turntable with a built in phono preamp in order to use this amp for vinyl playback.

The amp can power one set of passive speakers at 100 watts per channel and drive both 4 ohm and 8 ohm speakers. This power is derived from two PCS Texas Instruments chips inside the amp.

The amp has three knobs on the front which allows you to adjust treble and bass as well as the volume. There is a metal switch that powers the unit on/off with a very small red light letting you know when the amp is powered on and blue light when bluetooth is connected.

Now, let’s talk about the PROs of owning this little amplifier next:

The Pros of Owning the Fosi BT20A Amp

Size:

One of the obvious pros of this amplifier is the little size, allowing you to put it almost anywhere. If you do not have a lot of space for a traditional stereo set up, the Fosi is easy to squeeze into a tight spot.

Power:

Another pro is the overall power of the amplifier, which Fosi Audio lists at 100 watts per channel meaning this will easily power most speakers you can throw at it, from 8 ohms all the way down to 4 ohms.

Bluetooth:

Lastly, Fosi Audio included built in bluetooth on this little amplifier which means you can easily begin playing music via your phone without having to hook up a traditional sound source.

Before we talk about how the Fosi sounds, let’s look at a few cons I noticed…

The Cons of Owning the Fosi BT20A Amplifier

Appearance:

At the risk of sounding vain, I’ve come to realize that part of my love for this hobby of buying audio gear lies in the fact that a lot of it looks really awesome displayed at home.

This probably comes from my love of vintage audio pieces like my Marantz 2270 and my McIntosh MC 2505, both of which I have reviewed on this blog. I love sharing photos of these pieces while listening to music and people notice them and ask me about my gear when visiting my home, sparking fun conversations.

To me, there isn’t too much to look at with this Fosi amp. I know I said earlier that part of the PROs of owning the amp is its small size, but I think that small size leaves a rather boring looking amp that doesn’t draw much attention or spark any discussion.

I know…I shouldn’t expect much for just $80, but I wouldn’t enjoy sharing photos of this amp and let’s be honest, no one is going to ask me about it when they see it displayed on my shelf at home.

No Phono Input:

Most of these inexpensive Chinese amplifiers, like the Aiyima T9, do not have a built in phono stage which is what helps keep the price low. This isn’t a huge con for me, but it’s worth pointing out that if you are interested in buying this strictly for vinyl playback, you will need to either have a built in preamp on your turntable or spend more money on an external phono preamp.

Sound:

My biggest con with this amp is the overall sound presentation…let’s talk about that next…

How Does The Fosi BT20A Amp Sound?

I’ve thought a lot about how to discuss the sound of the Fosi as I think it appeals to two audiences, people who are just getting into this hifi hobby and want something cheap to start building a system with and then there are people who are like me who’ve been listening to audio their entire life and are curious how this could possibly sound good for such a cheap price.

Let me start by addressing people who might be new to buying audio gear and tell them that this amp, for just $80, will be a good starting point for you. It’s going to power your speakers and sound fine. If you are used to listening to music via airpods or bluetooth speakers, the Fosi will be an upgrade.

To me, the Fosi’s sound is very typical of budget Class D amps that provide a lot of power, but does not provide the music playback with a lot of detail, accuracy or soundstage. It pretty much sounds like an $80 amplifier and that’s not a bad thing if you’re just getting started.

However, after you buy the Fosi, I would encourage you to continue saving money and eventually upgrade to a class A/B amplifier instead, something like the Emotiva BasX A2m for $349 or the Cambridge AXA25 for $399.

The Emotiva and Cambridge amps, even though they are more expensive than the Fosi, will provide you with a more lively listening experience and you will hear things in your music you’ve never heard before.

Now, for anyone who has been in the hifi hobby for awhile and have been tempted to buy this and compare it to their other hifi gear, I’ll just go ahead and tell you that this little amp just isn’t going to compare.

I would say you might buy this because it’s small and cheap and can fit almost anywhere. It would be a good enough unit to use as a secondary system in a small room or even in a garage workshop where you don’t mind it getting dirty.

But I wouldn’t buy this for critical listening. All of the exciting musicality you hear with other amps, even budget Class A/B models like I mentioned above, simply isn’t present in this budget Class D amp.

Should You Buy The Fosi BT20A Amplifier?

I would sum up my buying advice as this: if you are a beginner to hifi audio and want to get started with an affordable amp, the Fosi will work fine for you.

But if you are a serious critical hifi listener, I would save my money and invest $80 somewhere else into your stereo system.

Before I let you go Fosi Audio’s slogon on their box states that the Fosi BT20A is “Hifi Made Fun”. Is the Fosi BT20A actually fun or is it kind of boring?

I want to dig into that more next…

Is The Fosi BT20A Hifi Made Fun?

I found the slogan on this box, Hifi Made Fun, kind of ironic because too me, the Fosi wasn’t really that much fun.

But, let’s talk about the definition of “fun” because maybe my idea of fun is different from Fosi’s and even yours.

The reason I’m saying the Fosi wasn’t much fun is because not once, while listening to music via the amp, was I ever surprised by the sound. And to me, what makes this hobby of listening to different gear fun, is finding a component that surprises you with sounds you’ve never heard before. That could be in the form of detailed guitar parts you’ve never recognized before or better 3D soundstaging so you can tell where an instrumentalist is sitting in the recording studio or even just tighter bass that provides a better rhythmic performance overall. None of that ever happened to me while listening with the Fosi and so it was never really a “fun” listening experience.

But, and this is why I wrestled with how to present this review, I suppose one could argue that the Fosi is fun because of its small size and ability to power almost any speaker on the market. I guess you could say it’s fun to spend $80 and get a tiny amp with a lot of power.

You could say it’s fun because the cheap price allows new buyers to get interested in the hifi hobby. That’s why I think people building their first stereo system or someone who wants an inexpensive second system will find the Fosi fun.

But if you’re looking for a fun AUDIBLE experience, I would suggest saving money and buying a class A/B amp from Emotiva, Cambridge or similar companies.