QUICK TAKE: Small Wonder! – the amazing Radsone ES100 EarStudio Bluetooth Receiver

Look how cute the box is!!

Every time I power up my tiny Radsone ES100, I am astonished:

  • Astonished that it turns nearly any wired pair of earphones into wireless Bluetooth earphones, and does so with vastly improved (rather than degraded) sound quality, at least as compared to your smartphone
  • Astonished that it retails for only US $99 (but you can often get it for $20 less, see below)
  • Astonished that it sounds as gorgeous as it does and supports so many codecs, including: LDAC, aptX-HD, AAC, aptX, SBC
  • Astonished that it incorporates a dual-mono design with a separate AK4375a DAC chip for each channel! (I mean, holy cow!)
  • Astonished that it has both 2.5 mm balanced and 3.5 mm unbalanced outputs
  • Astonished at how light and tiny it is, and that its battery life (and Bluetooth range) are so great
  • Astonished that its optional smartphone app enables you to configure and hack every geeky, functional parameter of the thing
  • Astonished that a product so refined and mature comes out of nowhere from a company you’ve never heard of
  • Astonished that – far from slinking silently away in the night never to be heard from again (as sometimes happens with one-hit wonder companies you’ve never heard of) Radsone just released a “Mk II” version of the ES100.

A picture’s worth 1000 words, so…

The box is about the size of… I dunno, a really, really tiny box.
Cute little guy. Not shown here, there’s also an LED in the center of the unit that shows power on/off, connection and charging status.
Three-quarter view showing the belt/shirt clip with the Radsone logo.
Top to bottom: microphone for phone calls (how cool is that?), volume control and 3.5 mm single-ended jack.
Left to right: 2.5 mm balanced jack, multi-function button (play/pause and power on/off), track forward/ reverse.

I’m not going to repeat all of the features enumerated on the Radsone ES100 product page. Rather, let me share a few personal favorites.

That’s App-mazing (sorry)!

I mentioned earlier that Radsone’s EarStudio app (available for both Android and iOS devices) lets you tweak the ES100 in ways that would certainly never occur to me (and, unless you’re a DAC chip designer, probably not to you, either — no offense).

Of course there’s a very robust graphic equalizer with lots of presets, including custom ones that you can store. But there are also deeply technical (yet well explained) options that let you tailor a great deal about how the ES100 functions and sounds.

For example, there’s a power mode in which the unit powers on whenever current is flowing through its USB power port, and then powers down whenever current isn’t flowing. This mode enables you to keep an ES100 in the car, if your car (like my 2011 Prius) doesn’t natively do music over Bluetooth. Whenever you start your car, the ES100 (connected via USB to your “cigarette lighter” charger) powers up and connects via Bluetooth with your phone, and later powers down when you turn off your engine. Connect the headphone jack on the ES100 to the AUX jack in your car and…. BOOM! Instant Bluetooth music streaming with an audiophile amplifer/DAC:

The micro-USB port (not shown) plugs into the top of the ES100.

And here are a handful of EarStudio smartphone app screen grabs. As you look at them, remember that the ES100 still retails for only 99 bucks:

By the way, if you want a pretty exhaustive tour of the EarStudio app (and you have about 40 minutes on your hands) check out YouTube headphone savant Zeos‘ review of the ES100, in which he waxes at length about the considerable glories of the Radsone EarStudio app:

Okay, Steve, so how’s it sound?

I’ll save you some time. It sounds freaking amazing. Let’s put it this way: the DAC, headphone amplifier and Bluetooth receiver functions of this little guy are so refined that I can listen to Spotify (or, even better, high-res music files on Amazon Music) on my iPhone through the ES100 and it sounds as good as or better than through the CD-ripped, lossless FLAC files played through my iBasso DX80 dedicated DAP. And that’s saying something.

The ES100 also makes a tasty streaming DAC for my PSB Alpha PS1 desktop system:

Yeah, my desk is a mess, but the sound is amazing.
Radsone ES100 running balanced out (!) to my new oBravo Cupid IEM’s. Sweet!

Just buy one, for your car, for your phone, for your desktop speaker system or as an outboard DAC for your laptop (yeah, it does that too). Heck, be like me and buy at least 2 of them.

Pricing and the Mk II:

The Radsone ES100 was recently upgraded to a Mk II iteration. The changes are essentially cosmetic, but welcome none the less. Apparently the physical buttons have been improved, and the entire plastic body has a coating to resist scratches. Good stuff.

I also mentioned earlier that the ES100 retails for US $99, but that you can sometimes get it cheaper. I am referring to the crowdfunding web site Drop.com (formerly called Massdrop), which periodically sponsors a “drop” of the ES100 for $79 rather than $99. Hey, 20 bucks is real money, so if you can wait a bit, click here and let Drop.com know that you’d like them to sponsor another run of the ES100, and they’ll email you when they do.

Not-all-that-quick Take

Well, this review ran a bit longer than I’d anticipated, but I hope it has piqued your interest about the Radsone ES100, which I can’t recommend highly enough.

And now… a Radsone IEM!

By the way, Radsone not long ago released their first IEM’s the Radsone HE100, a pair of tiny, single dynamic driver IEM’s that are said (not surprisingly) to pair splendidly with the ES100. Check them out on Amazon, where the current retail price is $99.

And hey, Radsone, if you’re listening, would it kill you to send me a pair to review?

Until next time, be kind and enjoy your music!


4 thoughts on “QUICK TAKE: Small Wonder! – the amazing Radsone ES100 EarStudio Bluetooth Receiver

  1. Glad to see you’re back on the blog! I’m going to have to try this one out – new phone, not as great as the old one in terms the audio quality, and despite trying several wired and wireless IEMs, I’ve discovered I hate having things sticking into my ears. This might just be what the doctor ordered. Kol tuv.

    1. Thanks, Jeff! Do check it out and let me know what are you think! By the way, do you have any Texas relatives? I know some people with the exact same surname, spelled the same way. 🤔

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s