In this article, I’m reviewing the xDuoo TA-20 Plus tube headphone amplifier. The TA-20 Plus is fully balanced from input to output and delivers up to 2000mW of output power. It’s priced at $499.

Disclaimer: This sample was provided by Apos Audio for an honest review. All observations and opinions here are my own, based on my experience with the product.

xDuoo TA-20 Plus

Design

The TA-20 Plus comes in xDuoo’s signature gunmetal grey colour with a textured but smooth finish. It’s a reasonably compact but dense unit, weighing in at 4.3kg. You can tell that it’s built well just by the look and more specifically by the feel of the device.

There are a couple of features on the front panel that stand out, namely the dynamic VU meter and the bright red volume knob. The volume knob is also a button that cycles through the 3 input options.

Another eye-catching feature is the LED volume display with an orange glow that matches the colour of the tubes and VU meter. Lastly, the front panel hosts the 6.35mm unbalanced, 4.4mm balanced and XLR balanced headphone outputs.

Moving to the rear, we spot a duo of RCA inputs, accompanied by a single XLR and a 4.4mm balanced input. Additionally, a handy RCA line-out feature lets the TA-20 Plus step into the preamp role when needed.

Alright, let’s talk about those tubes now. We’ll cover the big 5Z4P tube first, which is for rectification. The rectifier tube converts AC voltage to a pulsating DC signal. A capacitor then stores charge during the peaks of the pulsating DC and releases it during the troughs, effectively smoothing out the waveform. This rectification process introduces harmonics and subtle distortions to the signal. These harmonic components can contribute to the amplifier’s overall tonal characteristics, potentially adding a vintage or “tube warmth” quality to the sound.

Next up, we incorporate 2 12AU7 tubes for audio processing. These tubes collaborate seamlessly with a class-A buffer in the output stage. This configuration offers the best of both worlds—delivering the warmth and analog charm of tubes while ensuring robust power delivery and a low-impedance output. This makes the TA-20 Plus compatible with a wide range of headphones.

Sound

Diving in with the xDuoo TA-20 Plus, listening to the amplifier is like a smooth ride down a musical river. Unlike some darker-toned tube amps, the TA-20 Plus manages to steer clear of veiled sound, presenting a transparent yet lush rendering of your favourite tunes.

The inclusion of 2nd order harmonics acts as a secret sauce, infusing notes with richness and dimensionality. This harmonious touch doesn’t fall into the trap of sluggishness, thanks in part to the Class-A amplification under the hood.

Now, let’s talk about compatibility. The TA-20 Plus is a great match for a variety of headphones thanks to its low output impedance. However, sensitive IEMs don’t fare as well. The faint whisper of background hiss and sporadic pops is downright distracting. Yet, swap those IEMs for a pair of headphones with a bit more resistance, and the TA-20 Plus sounds rich in detail with captivating bass extension.

Speaking of which, the lows on this amplifier are nothing short of impressive. It’s not just about the depth; it’s the way it extends, adding a profound character to the sound. And when it comes to the stage, the TA-20 Plus doesn’t disappoint. The soundstage sprawls out, creating a sense of space that allows each instrument to breathe and dance within the mix.

Verdict

In essence, the xDuoo TA-20 Plus is a fantastic way for people to get started in the world of tube amps or to enhance an existing setup. Its ability to balance smoothness with dynamism, harmonics with clarity, and compatibility with a variety of headphones positions it as a versatile companion for those seeking a more analogue experience.

Furthermore, the TA-20 Plus, despite not being cheap, is still more affordable than many of its similarly specced contemporaries. Beyond its affordability and great sound, the amplifier’s design, build quality, and aesthetics make it a pleasure to have on the desktop.

Specifications

• Power Source: AC
• 110V(100-120V)/220V(220-240V)
• Gain: +18dB
• 6.5mm Headphone Output :
  • Output Power: 2000mW (32Ω load)
  • Frequency Response: 10Hz~80kHz(±0.5dB)
  • Crosstalk: 74dB
  • SNR: 113 dB
  • THD+N: 0.05%
• 4.4.4mm/XLR balanced Headphone Output
  • Output Power: 2600mW (32Ω load)
  • Frequency Response: 10Hz~80kHz(±0.5dB)
  • Crosstalk: 95dB
  • SNR: 113 dB
  • THD+N: 0.05%

• Suitable Headphone Impedance: 16Ω~600
• Size: 10.2 x 7 x 6 inches (26.0 x 17.7 x 15.3 cm)
• Weight: 9.5 lbs (4.3 KG)