The Qudelix T71 is a powerful, portable, and feature-packed USB DAC that may just provide a revolutionary audio experience for audiophiles and average consumers alike. This detailed review will unpack this unique device’s key features, design, sound quality, and audio performance so that you can decide if this is the new and exciting USB DAC that you have been waiting for. So let’s get started!

Key Specifications

• Core Processor: NXP iMXRT600 ARM + DSP Core
• DAC Components: Four ES9219C SABRE HiFi® DACs
• Amplifiers: Two Texas Instruments INA1620 AMPs
• Connectivity:
  • Unbalanced output: max. 4V RMS (3.5mm)
  • Balanced output: max. 8V RMS (2.5mm & 4.4mm)
  • Input: USB-C
• Battery Life:
  • 4 to 10 hours (1000mAh Battery)
• Audio Modes:
  • 2.0 Channel Stereo Mode: 384KHz / 32-bit
  • 7.1 Channel Surround Mode: 96KHz / 32-bit
• Features:
  • 20-band Equalizer, PEQ/GEQ
  • Two High Sensitivity MEMS USB Microphones
• Software Compatibility:
  • PC Chrome App for Windows/macOS/Linux
  • Android app
• Case and Dimensions:
  • 84 x 40 x 1.6mm
  • Weight: 75g
  • 240 x 135 Full Color LCD
  • Four LED Buttons

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Overview

You may have heard the Qudelix name in the past few years as they built a great little device called the 5K (you can read our review of it here), but in August 2023 they launched a new device, the Qudelix T71. It’s a high-performance USB Digital-to-Analog Converter (DAC) engineered to process multi-channel audio from various types of source devices. Unlike conventional DACs that are designed for two-channel stereo audio input, the T71 boasts the capacity to receive up to eight channels of digital audio and downmix it to a two-channel stereo output for headphones.                    

Design & Build Quality

The Qudelix T71 comes in an elegantly designed aluminum CNC body with a plastic bottom case. The compact size of the device (84 x 40 x 1.6mm) and the fact that it’s lightweight (75g) make it a perfect companion for music enthusiasts and gamers on the go.

Display and LED Buttons

The top of the device has a 240 x 135 color LCD for viewing, navigating, and configuring the T71’s various settings. There are also two LED buttons along each side of the device, and they are color-coded for easy identification.

Connections

On one end, the Qudelix T71 features a USB-C port for connection to your source device. This can include Windows, MacOS, and Linux devices, Android and Apple smartphones and tablets, Sony PlayStation 5, and the Nintendo Switch.

On the other end, we have a 3.5mm unbalanced connection, 2.5mm and 4.4mm balanced connections, and a USB-C port intended for the IEM that Qudelix is developing. Despite the USB-C connection, it currently does not support USB-C headphones or adapters.

The T71 also features two high-sensitivity MEMS microphones built into the chassis, which can be used for calls and meetings.

Size Comparison

Here’s a size comparison between the iFi Zen DAC V2, Creative SoundBlasterX G6, and the Qudelix 5K.

And here you can see the size of the T71 related to the 5K.

Battery

The Qudelix T71 has a built-in 1000mAh battery, which Qudelix says is user-replaceable (the same goes for the 5K, too). The battery allows the T71 to be used with portable devices, such as smartphones, tablets, and portable game consoles, without needing to be powered by those devices. 

Sound Quality

The sound quality of the Qudelix T71 is one of its standout features, and there is much to cover here. It’s equipped with four ES9219 DACs and two INA1620 Operational Amplifiers (OPAMPs) – a combination of high-quality audio circuitry designed to deliver powerful and optimal sound to any headphones or IEMs. 

Power and Noise

The T71 easily drives my Beyerdynamic DT 770 Pro 80ohm headphones, as well as my Fostex T40RP MK3 planar magnetics, not something I can say about every portable USB DAC out there right now. Qudelix guarantees absolutely zero hiss or background noise when using not only headphones but also sensitive IEMs. Testing the T71 with my HiBy Seeds II, while not the most sensitive or high-end IEMs out there, the audio was clean and hiss-free.

Stereo Sound

Listening to regular stereo audio through the Qudelix T71 is a great experience. The sound comes out clean, leaning more towards a neutral sound profile with a little bit of warmth. It reminds me a lot of the sound quality of the Qudelix 5K (a good thing), but the T71 lets the audio breathe a bit, mainly when there is a lot of dynamic range and soundstage to the audio. This is most noticeable when listening to orchestral pieces, but the dynamics of the audio output from the T71 also makes listening to all types of music enjoyable. As always, these factors will depend on the quality of the recordings you are listening to and how good your headphones or IEMs are.

I want to highlight a couple of examples where I noticed the T71 really shines when it comes to stereo audio, and this is related to binaural audio. Without going too far into it, Binaural audio is a method of recording and reproducing sound that creates a 3D stereo sound sensation for the listener. Listening to the appropriately titled Pearl Jam album “Binaural,” which features tracks recorded using the method described above, you get a sense of the vocals and instruments being around you instead of just being directed at you. Another example is the video game Soma, which natively features binaural audio. It results in an incredibly immersive experience when playing the game.

Surround Sound and Dolby Atmos

Multi-channel audio is the main selling point of the Qudelix T71, so how do things sound? Let’s go through the various scenarios you would be using this in.

Music

Music recorded in 5.1, 7.1, or Dolby Atmos sounds absolutely phenomenal when using the T71. You get an accurate sense of direction for instruments. They are accurately separated, and the soundstage does not suffer when downmixed to 2.0 stereo headphones. Listening to a 5.1 copy of Pink Floyd’s “Dark Side of the Moon,” you can get a real sense of what the T71 can do. Even the Dolby Atmos copy sounds excellent, and I am not usually a fan of Dolby Atmos mixes for music.

Comparing the experience to my other surround sound DAC/AMP, the Creative SoundBlasterX G6, the T71 doesn’t lose the dynamic range when it converts the multi-channel audio to 2.0 stereo, nor does it make it sound flat or dull. To my ears, the audio authenticity is preserved through the entire downmixing process.

Movies

I tested several movies using a Windows PC, using local files that I have, as well as through the Netflix app. The audio mix is preserved accurately when downmixed from 7.1 to 2.0, and no detail or dynamic range is lost. In fact, I almost feel as if I’m getting more soundstage when using the T71 as opposed to my Creative SoundBlasterX G6. Dolby Atmos also works, and it works well.

Gaming

I have used the T71 extensively for gaming. In fact, it has completely replaced my Creative SoundBlasterX G6 for this purpose. I relied heavily on the SBX surround feature in the G6 for surround audio in PC and PS5 games, but the T71 does a better job of positioning audio. The audio mix sounds perfect when playing Dolby Atmos-supported games such as Modern Warfare 3 (the 2023 version), Metro Exodus, and Cyberpunk 2077. Detail and positioning are preserved, and in cases such as Modern Warfare 3 multiplayer, where sound identification and positioning are crucial, the T71 does an absolutely fantastic job.

Performance

The Qudelix T71 performs excellently with its high-powered NXP iMXRT600 ARM + DSP Core and four ES9219 SABRE HiFi DACs. With this, you get up to 384KHz / 32-bit support in stereo mode and up to 96KHz / 32-bit support in 7.1 surround mode. 

Power Output

The T71 has two Texas Instruments INA1620 AMPs, allowing the device to offer an unbalanced output max of 4V RMS (3.5mm) and a balanced output max of 8V RMS (2.5 & 4.4mm). This impressive output range ensures that the T71 can drive a wide array of headphones and IEMs without issue.

Battery Life

Powered by a 1000mAh battery, the T71 lasts between 4 and 10 hours on a single charge, according to Qudelix. On average, I was getting 7-8 hours when using my iPad Pro and my smartphone (Galaxy Fold 5).

Features

The Qudelix T71 is packed with features, and I feel these will be the main selling point for most who are interested in the T71.

Automatic Detection of Incoming Audio Channel Format

One of the standout features of the T71 is its ability to automatically identify the incoming audio channel format. The device’s screen displays real-time channel information of the incoming audio, providing an indication of the format the T71 is currently receiving from the host source device. If the audio is 5.1 or 7.1, it then uses a proprietary algorithm to downmix the audio output to 2.0 to pass it to the connected headphones.

Dynamic Range Enhancement

The Qudelix T71 is designed to process multi-channel audio while preserving the relative dynamics of the original audio source. This capability is key to maintaining the intended balance and spatial positioning of different audio elements within a multi-channel audio mix, creating a realistic, immersive sound experience. As I indicated in the Sound Quality section, I feel the T71 does precisely what it promises to.

High Sensitivity Dual MEMS Microphone

The T71 has two microphones integrated into the device’s chassis, which is effectively seen as a USB mic when used with a computer or laptop. In my limited testing, the microphones sound clear, and the device doesn’t need to be beside you to pick up audio. I could easily see this as a viable option for some people who don’t want to invest in a dedicated microphone but want to use their audiophile headphones for meetings or online gaming.

Display and Navigation

 The Qudelix T71’s display will be the primary way you will interact with the device and see relevant information. The top two buttons (green and orange LEDs) are used for navigation when pressed once, and when long-pressed, they have different functions depending on which screen you are on. The bottom two buttons (red and blue) have different functions per screen and can also be long-pressed, resulting in two actions per button per screen. For example, on the Home View screen, the bottom buttons control the volume. It’s an effective and efficient way to limit the number of buttons needed on the device and not have to include a touch screen for extra functionality.

There are three display views on the device:

1. Home View displays information such as the device and source volume, selected USB mode, which connection is currently in use, sampling rate, and surround mode.
2. Equalizer View displays whether EQ is turned on or off and allows you to select the saved profiles.
3. DAC/Amp View allows you to change the audio profile and gain and filter selection.

Companion App

The T71 has many settings that can be set or customized, either through the on-device screen and LED buttons or through the Chrome web app (download here). Qudelix promises that the Qudelix app on Android that currently works with the 5K will be updated to support the T71 (through a USB connection as the T71 lacks Bluetooth), but the iOS version will likely not work with the T71 due to the limitations of iOS.

UPDATE: The Android app has been updated as of April 30, 2024 to support the T71 through a USB connection.

The companion web app works and looks exactly the same as it does with the 5K. For example, you can see the warranty left on the device and the current firmware version from the main page. I want to note that there have been 17 firmware updates since the device was released in August 2023. Like the 5K, Qudelix shows how much they care about supporting their products and listening to user feedback, as many of the firmware updates were to resolve issues or add features based solely on user feedback.

If we go down to the USB tab in the Input section, we can see the options for the various modes: Stereo, Surround, PS5, and Nintendo Switch. Separate modes are needed for the PS5 and Switch as the T71 is a UAC 2.0 device, but the gaming consoles only support UAC 1.0 devices. On top of that, the Switch only supports a bit depth of 16-bit.

DSP

Lastly, let’s look at the DSP options, as this will probably interest (and confuse) most users. The T71 has two EQ options: USR Eq and SPK EQ. They may look the same, but they serve different purposes.

When you apply an EQ from the Auto EQ preset, it will apply to SPK EQ, so if you manually want to create an EQ for your headphones or IEM, this is the place to do it.

Once you have your EQ in place, go to the USR EQ tab and perform whichever minor tweak you need for your use case.

The idea behind this concept is that you can EQ your headphones/IEMs to whatever your target is in the SPK EQ tab, and then, in the USR EQ tab, you can apply, say, a bass boost for movies and shooting games. I personally haven’t encountered a need for this yet, but the flexibility of this implementation seems pretty innovative.

Final Thoughts

The Qudelix T71 is a truly unique device. Its combination of excellent sound quality, exceptional performance, and an array of user-friendly features makes it a standout product for not just portable DACs but desktop ones as well. With the T71, you get an unparalleled surround sound experience for headphones and IEMs without sacrificing anything for stereo audio.

Add on top of that the well-done companion app, the no-nonsense design of the device, responsive and ongoing support from Qudelix, and the sheer flexibility of how the T71 can be used, I think this might be the most underrated audio product of the past year.

That being said, the Qudelix T71 is not without its issues. Currently, there is no way to “flip” the screen’s orientation so that the headphone connections are on the right side and the USB-C data connection is on the left. Not every situation will easily allow the current orientation.

UPDATE: The firmware update 1.4.0 now allows the screen orientation to be flipped.

As well, it’s disappointing that USB-C headphones and adapters do not work with the USB-C output connection. Finally, supporting headphones with in-line microphones would add a lot of value as not everyone will want to use the on-board mics.

The firmware update 1.4.0 now allows the screen orientation to be flipped.Overall, the Qudelix T71 is a fantastic device for music, gaming, and movies, excelling in both stereo and surround sound reproduction. Not only does it replace my Qudelix 5K for most portable use cases, but also my two desktop DAC/Amps: the Creative SoundBlasterX G6 and the iFi Zen DAC V2.

HiFi Oasis highly recommends the Qudelix T71.

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We are not always able to cover all details of a product, both hardware and software, in our reviews. If you have any specific questions you’d like answered about this product please feel free to leave a comment or contact us directly.