Dark or Light

Drop + xDuoo TA-84 Review

Tubey Goodness

Christopher Coke Updated: Posted:
Hardware Reviews 0

Drop just released its latest collaboration, an OTL tube amplifier made to drive demanding headphones like the HD6XX – that also just happen to be top picks for gaming. Is the Drop + xDuoo TA-84 worth investing in at a pre-order price of $349? Find out in this review!


  •     Current Price: $349, Pre-Order, Regular $399 (Drop
  •     Inputs: RCA, USB-C
  •     Headphone Outputs: 6.3mm TRS
  •     Preamplifier Output: RCA
  •     Dimensions: 10.6 x 6.4 x 4.6 inches
  •     Power Amplifier Tube: (2) EL-84
  •     Preamplifier Tube: (2) ECC-82
  •     Gain Switch: +16dB
  •     Amplifier
    • Output Power: 44mW (at 100 ohms), 83mW (at 300 ohms), 93mW (at 600 ohms)
    • Frequency Response Range: 10Hz – 80kHz
    • Crosstalk: 65dB
    • SNR: 102dB
    • THD+N: ≤1%
    • Recommended Headphone Impedance: 100-600 ohms (amp is not well suited for planar magnetic headphones and low impedance headphones due to OTL topology)
  •     DAC
    • DAC Chip: ES9018K2M
    • Sampling Rate: PCM 16 – 32 bit / 44.1 kHz – 384 kHz, DSD64 - DSD256
    • THD+N: 0.002@1kHz
    • S/N: 113dB
    • Crosstalk: 88dB
    • Compatible OS: Windows, Linux, Mac OS X, iOS, Android
  • Weight: 6.6 pounds

Drop + xDuoo TA-84 – Not Your Average Audio Accessory

Over the years, Drop has produced a number of different products that have become staples in the audio hobby. The Drop + Sennheiser HD 6XX is probably the best known among them, closely followed by the HD 58X, the Drop O2 amplifier, the Drop + THX AAA 789, the Drop + Alex Cavalli Liquid Carbon X, and more. The 6XX in particular rocked the audiophile hobby, bringing new people in with this new, accessible, and eminently impressive pair of headphones.

It has a rep.

With the TA-84, it’s breaking new ground. Partnering with xDuoo, it’s the company’s first-ever tube amplifier and it’s custom designed to match its most popular Sennheiser models and BMR1 speakers. It will also work well with other high-impedance headphones, like the popular Beyerdynamic DT-770s. It’s big and bulky and looks exceptionally cool on a desk top. It’s not neutral and colors the sound, but that’s exactly what it’s designed to do, and sounds great. It’s a specialized product that delivers on its specialty.

In many ways, the TA-84 is an answer. It’s designed to address some of the biggest concerns about tube amps while also addressing some of the biggest criticisms of the HD 6XX. Beginning with the first, tube amplifiers are a classic technology. They don’t measure the best and aren’t intended to. People use them for their unique character and warmth. At the same time, they can be noisy. Turning them on raises the noise floor on some models, which can be especially noticeable on sensitive headphones and IEMs.

The TA-84, on the other hand is what’s known as an output transformerless (OTL) amplifier. This design removes the transformer from the electrical topography and replaces it with capacitors. This lowers the noise floor substantially, to the point that the TA-84 is virtually black. There is no hiss or background noise whatsoever, allowing you to have analog warmth in an impressively clean signal.

The second part of its “answer” has to do with the HD 6XX, and to a lesser degree, the 58X. While the 6XX is loved for its neutrality, clarity, and natural timbre, its critics often cite that it’s also a relatively tamed, mild mannered pair of headphones. Plugging into the TA-84 instantly injects the cans with a low-end energy and body. They’re lose some neutrality, yes, but become more fun and engaging to listen to.

The downside to this design is that the TA-84 is recommended for high impedance headphones only. Drop suggests a range of 100 to 600 ohms, which is high enough that this amp really isn’t going to be a recommended fit for the majority of headphones today, even among audiophiles.

The power output also isn’t very high at 44mW for 100 ohms, 83mW at 300 ohms, and 93mW at 600 ohms. With that said, it features a high and low gain mode that adds or removes 16dB of volume and I still felt like my 6XX, 58X, DT-990, and Fiio FT3 had plenty of headroom. Still, in terms of sheer output, it’s on the low side. This is a somewhat surprising fact given how large it is. At 10.6 x 6.4 x 4.6 inches, it’s large. This isn’t an amplifier that you’re going to be sliding under a computer monitor.

And with the understanding that Drop recommends not using sensitive headphones, I tried it anyway. They don’t sound bad. What it does do is highlight some of the distortion from its circuit chain in the bass. More sensitive headphones reproduced bass with a slight buzzy quality. This wasn’t consistent from headphone to headphone, and was more difficult to notice about 60 ohms. I suggest sticking with Drop’s recommendation here, but it’s possible to have an enjoyable listening experience below 100 ohms with the right pair of headphones.

Drop + xDuoo TA-84 – A Quality DAC, Great for PC

Thankfully, it’s also a hybrid amp, so you won’t need to find space for a separate DAC on your desk. Alongside its amplification topology, Drop and xDuoo have integrated a ES9018K2M DAC chip that supports high-res audio. It supports bitrates of 16 and 32 bits with a sampling rate that spans from 44.1kHz to 384kHz. It also supports DSD files from DSD64 to DSD256. The measurements are much higher than the amplification section, but since you don’t buy tube amps for clarity specs, I’ll leave that to the spec section. 

Simply plug it into your PC over USB and it immediately activates as an external soundcard and takes all of its audio processing straight out of the PC (and all of its noisy componentry) and uses its own much higher-end circuits.

Even with a high-end gaming motherboard that touts its sound quality, I noticed an immediate uptick in audio quality switching to the TA-84. And that’s the core reason why you might choose something like this at all. By taking audio out of the PC, you get an improvement. Using components selected and integrated for sound quality gets you another. Adding tubes to the mix injects body and character to the listening experience that is especially good for gaming but is also beloved by many for pure music listening. This doesn’t transform your desktop audio experience but it definitely enhances it in a way that you’ll notice right away.

Drop + xDuoo TA-84 – Streamlined and Aesthetic

Despite its large size, the TA-84 is surprisingly streamlined. This hybrid amp only has a volume knob and single 6.35mm jack on the front. Around the back, you have a pair of RCA jacks for AUX inputs and outputting to speakers. There’s also a high/low gain switch and a USB Type-C port.

It’s very straightforward and great for newcomers, though I do wish there were some changes here. Where’s the balanced output? I’m not familiar enough with OTL amplifiers to know whether this would have significantly increased the price, but at $349 pre-order and $399 retail, I would have liked to have seen a 4.4mm balanced jack at least. Putting the gain switch on the back is also an odd move.

It certainly makes the front look clean, however. And the volume knob is excellent, with defined tactile notches and 42 volume steps for granular control. It can be a mite slippery, so some knurling or texturing would be welcome on a future version, but that’s a nitpick.

And while aesthetics might seem like a strange thing to highlight on an audio device, this is an expensive audio device, and one you’re going to be looking at on a daily basis. It be pleasant to look at, and I definitely think it is. The four exposed tubes look great on their own, but the whole unit has a steampunkish look to it that I think is really neat. This is true of most tube amps, but hey, good looks are a selling point and this has the potential to add a novel, functional upgrade to your desk on top of just being a good amp.

Final Thoughts

The Drop + xDuoo TA-84 isn’t going to be for everyone. You’ll need a pair of high impedance headphones to make the most of it, and at $349, it’s well priced for its market but expensive for the average listener. You’ll need to be a fan of tubes or tube-curious to really see the value here. If you do meet those criteria, it offers classic tube warmth that makes cans like the Drop + Sennheiser HD 6XX sing. If you’re considering a wholesale audio upgrade, buying both as a pair would be a good investment. If you can spend a little more, or don’t need the OTL design, there are other options out there that offer more power. But for what it is, this is a neat, great sounding amp hybrid.

The product described in this article was provided by the manufacturer for evaluation purposes. Some articles may contain affiliate links and purchases made through this will result in a small commission for the site. Commissions are not directed to the author or related to compensation in any way.

8.0 Great
  • Tube warmth without the noise
  • Decent pricing
  • Hybrid DAC/amp design
  • Easy tube rolling
  • Livens up the venerable HD 6XX!
  • Very large
  • High impedance headphones only
  • Relatively low power output


Christopher Coke

Chris cut his teeth on MMOs in the late 90s with text-based MUDs. He’s written about video games for many different sites but has made MMORPG his home since 2013. Today, he acts as Hardware and Technology Editor, lead tech reviewer, and continues to love and write about games every chance he gets. Follow him on Twitter: @GameByNight