Truly balanced
A DAC and amp for each channel, with up to 78mW balanced.
Skip to content
Balanced Bluetooth in your pocket.
A compact Bluetooth DAC/amp with dual AK4377A DACs, a CSR8675 chip, 2.5mm balanced and 3.5mm outputs, and USB DAC mode.
Awaiting stock arrival date — order now to reserve one from the next delivery. Nothing to pay until it arrives.
Order by 2pm, Monday to Friday, for next day delivery. Destination and stock availability apply.
Not sure it’s your perfect match? Talk to an audio specialist
A little extra. A better pairing.
Hand-picked pairings for this product. Choose one — we'll add them together.
MEET THE BTR3K
A compact Bluetooth DAC/amp with dual AK4377A DACs, a CSR8675 chip, 2.5mm balanced and 3.5mm outputs, and USB DAC mode.
A DAC and amp for each channel, with up to 78mW balanced.
Bluetooth 5.0 with dual oscillators for reduced jitter.
Connect via USB-C, with FiiO Music app control.
A DEEPER DIVE
The FiiO BTR3K is a pocket-sized Bluetooth DAC and headphone amplifier with a truly balanced design. Two AKM AK4377A DAC/amp chips, one per channel, drive a 2.5mm balanced output (78mW) and a 3.5mm output (25mW), with a 122dB signal-to-noise ratio. A Qualcomm CSR8675 Bluetooth 5.0 chip receives LDAC, aptX HD and AAC, it works as a USB DAC, and its battery lasts about 11 hours. It won VGP Life Style awards in 2021 and 2024.

Building on what made the BTR3 so good, the BTR3K adds a balanced output. It is truly balanced, with a DAC and amplifier carefully paired for each of the left and right channels, for the purest possible sound.
The two high-performance AK4377A chips give 50% more power than the AK4376 in the BTR3, with much better measurements and sound.
| Output power (32Ω) | 78mW balanced (2.5mm) · 25mW single-ended (3.5mm) |
|---|---|
| Signal-to-noise | 122dB (A-weighted) |
| Distortion | −107dB |
| Balanced output | Noise floor 2µV · crosstalk 118dB (1kHz) · phase shift 0.03° (10kHz) |

The dual-oscillator system from the BTR5 comes to the BTR3K: separate 22.5792MHz and 24.576MHz clocks for the 44.1kHz and 48kHz families greatly reduce jitter, so Bluetooth and USB audio are reproduced more accurately and stably at every sample rate.

The premium, low-power Qualcomm CSR8675 has a 120MHz DSP and handles 24-bit transmission and processing, for excellent sound whether you are watching videos, listening to music or gaming. Bluetooth 5.0 means faster pairing and a more stable signal, with LDAC, aptX HD, aptX Low Latency, aptX, AAC and SBC, and a range of about 30m unobstructed (about 4m with LDAC set to quality priority). An RGB light shows the codec at a glance: blue for SBC, cyan for AAC, purple for aptX and aptX LL, yellow for aptX HD and white for LDAC.

The BTR3K pairs with and remembers two Bluetooth devices at once, so you can switch between, say, your phone and tablet without re-pairing. Its volume is adjusted separately from your phone’s for finer control, and it remembers your preferred level. When you play music with the FiiO Music app, you can also control the BTR3K remotely from your phone.

An omnidirectional microphone, call controls and Qualcomm’s eighth-generation cVc noise suppression keep background noise out of your calls, and you can call up your phone’s voice assistant without taking your phone out.
The BTR3K recognises what kind of headphones you plug in and adjusts its output. With headphones that have CTIA in-line controls, their microphone and play/pause, volume and track buttons work too.
Connect the BTR3K to a computer over USB-C and it works as a USB DAC. You can listen while it charges: a full charge takes about 1.5 hours and gives about 11 hours of playback. It can bring Bluetooth to older speakers or a car stereo, upgrade your computer’s audio, or go with you on the move.

The aluminium alloy body is wrapped in an arc of 2.5D glass, like the latest smartphones, with an oleophobic coating that resists fingerprints, high-contrast lettering and a smooth texture. A symmetrical, detachable rear clip makes it easy to wear on the go.

| DAC and amp | 2 × AKM AK4377A · dual crystal oscillators |
|---|---|
| Bluetooth | Qualcomm CSR8675, 5.0 · LDAC, aptX HD, aptX LL, aptX, AAC, SBC · A2DP, AVRCP, HFP, HSP |
| Outputs | 2.5mm balanced (78mW @ 32Ω) · 3.5mm (25mW @ 32Ω, CTIA in-line controls) |
| USB | USB-C: USB DAC and charging |
| Battery | 330mAh · about 11 hours · about 1.5 hours to charge · auto standby |
| Size and weight | 58 × 25 × 11mm · 23.5g |
THE FINER DETAILS
Know what you’re choosing.
Find the right fit for your setup.
Specifications are based on manufacturer information and may change. Battery life varies with use and settings.
FROM FELLOW LISTENERS
The FiiO BTR3K Bluetooth Headphone Amp has completely transformed my wireless listening experience — and I’m beyond impressed! This little powerhouse delivers audio quality that rivals, and in many cases surpasses, wired headphones. If you’re serious about sound, the BTR3K is an absolute must-have.
???? Sound Quality That Stuns:
The clarity, depth, and detail coming out of this tiny amp are nothing short of incredible. Every track feels alive — the bass is firm and punchy, mids are rich and full, and the highs are crisp without ever sounding harsh. Whether I’m listening to jazz, rock, or high-res recordings, the BTR3K reveals layers I hadn’t noticed before.
???? Seamless Connectivity:
Pairing is instant and stable. It supports all the major high-quality Bluetooth codecs — which means I get top-tier wireless audio from my phone and laptop with zero fuss. Connection stays solid even across rooms, and switching between devices is smooth and reliable.
???? Perfect for Headphones of All Types:
I’ve used it with both easy-to-drive earbuds and demanding over-ear headphones — and it handles them all with confidence. The built-in amp is powerful enough to drive more stubborn headphones and brings out their full potential.
????♂️ Sleek, Portable, and Durable:
The BTR3K feels like a premium device in hand — solid, compact, and stylish. It clips on securely and travels with me everywhere, from my daily commute to long flights. The battery life is excellent too — lasting well beyond a full day’s listening on the go.
???? Exceptional Value:
For the price, it’s hard to imagine a better Bluetooth amp. FiiO has struck the perfect balance of performance, features, and portability. It elevates everything I listen to, and that’s priceless.
⸻
In short, the FiiO BTR3K delivers jaw-dropping wireless audio in a tiny package. It’s one of the best upgrades I’ve made to my gear — easily a 5-star product I’ll keep recommending to everyone!
Helpful?
We invite customers who bought from us to review what they bought, and we publish every genuine review, good or bad. Our review policy
GOOD TO KNOW
Something else on your mind?
Every UK order has a free delivery option, and orders of £50 or more qualify for free next day delivery. Order by 2pm, Monday to Friday, for next day delivery; orders placed after 2pm, at the weekend or on a bank holiday are dispatched on the next working day. Stock availability and destination also affect arrival — check the options shown at checkout.
Pre-orders ship when stock arrives; the next day service starts after dispatch. Full delivery information
Return within 14 days for any reason, or within 30 days if faulty, with free return postage. See our full Returns Policy for conditions and how to start a return.
Absolutely. Tell us what you listen to and the headphones you have — or the ones you’re considering — and we’ll help you find a suitable pairing. Chat with us
Use the Price Beat option on this page to send us the competing offer. The team will review your request; it isn’t an automatic discount. How Price Beat works
KEEP EXPLORING
Need a hand choosing your next listen, or help with an order?
Send us a messageLeave a message and one of the team will reply as soon as we’re back. If you’d rather not wait, amp3 AI can help now.
amp3 AI is automated. It can provide product advice, check your order and our stock, and leaves anything else for the team.