Warm Up Your Ears With The Drop + xDuoo TA-84 Tube Amp

Warm Up Your Ears With The Drop + xDuoo TA-84 Tube Amp

Drop is famous for their key caps, switches and keyboard design but that is not the only thing making noise on their storefront.  They have also collaborated with a variety of audiophile companies to develop amps, DACs, headsets, speakers and even a turntable.  One of their newest products is a tube amp for high-impedance headphones, the Drop + xDuoo TA-84 and they were willing to send one over to test with.  Along with the tube amp came another collaborative product, a pair of Drop x Sennheiser HD 6XX headphones.

The output transformerless TA-84’s are not for everything mind you, they are designed for headphones with an impedance between 100 ohms to 600 ohms, planar magnetic headphones and low impedance sets will likely suffer from frequency response and volume issues.  On the other hand if you’ve invested serious money in your headset, you should have a decent source to feed them with.

Product Specifications

Drop + xDuoo TA-84 Tube Amplifier

  • Model Number: TA-84
  • Inputs: RCA, USB-C
  • Headphone Outputs: 6.3 mm TRS (¼”)
  • Preamplifier Output: RCA
  • Dimensions: 10.6 x 6.4 x 4.6 in (26.8 x 16.3 x 11.6 cm)
  • Weight: 6.6 lbs (3 kg)
  • Power Source: AC 110V (100-120V) / 220V (220-240V), selectable
  • Power amplifier tube: (2) EL-84
  • Preamplifier tube: (2) ECC-82
  • Gain switch: +16 dB
  • Output Power: 44 mW (at 100 ohms), 83 mW (at 300 ohms), 93 mW (at 600 ohms)
  • Frequency response range: 10 Hz – 80 kHz (± 0.5 dB)
  • Crosstalk: 65 dB
  • SNR: 102 dB
  • THD+N: ≤1%
  • Recommended headphone impedance: 100 ohms – 600 ohms
    • (amp is not well suited for planar magnetic headphones and low impedance headphones due to OTL topology)
  • DAC Chip: ES9018K2M
    • Sampling rate: PCM 16-bit – 32-bit / 44.1 kHz – 384 kHz, DSD64 – DSD256
    • THD+ N: 0.002% (at 1khz)
    • S/N: 113 dB
    • Crosstalk: 88 dB
  • Compatible operating systems: Windows, Linux, Mac OS X, IOS, Android

Massdrop x Sennheiser HD 6XX Headphones

  • Colour: Midnight blue
  • Transducer principle: Open, dynamic
  • Frequency response: 10 Hz – 41 kHz
  • THD: < 0.05%
  • Nominal impedance: 300 ohm
  • Cable length: 6 ft (1.8 m)
  • Connector: ⅛ in (3.5 mm)
  • Weight without cable: 9.2 oz (260 g)
  • 3 year warranty

$399.99 USD list – Drop + xDuoo TA-84 OTL Tube Amp/DAC

The price will be $329 until September 26th, after that the pre-order price will be $349 until end of the first run.

$219 USD list – Massdrop x Sennheiser HD 6XX Headphones, on sale for $199

Manufacturer Description

“Take a look—or a listen—at the last ten years here at Drop, and you’ll notice no shortage of award-winning amplifiers. Despite this decade-long discography, there’s one type of amp we haven’t touched. Now, it’s finally coming down the tube. That’s right: our first all-tube OTL amplifier is here—complete with a rock-solid DAC stage to complete any signal chain. Meet the Drop + xDuoo TA-84 OTL Tube Amp/DAC. Designed to deliver signature tube “warmth” without excess noise, this compact desktop powerhouse utilizes Output Transformerless (OTL) topology to manage signal without a transformer, greatly reducing distortion. For the preamp phase, it features dual ECC-82 tubes; and for the power amp phase, it runs dual EL-84 pentodes—both popular options in the audiophile amplifier space. To hit that sweet spot with any set of headphones (or powered speakers), the TA-84 is also equipped with an ultra-precise stepped potentiometer for volume control, plus a gain switch to further control the output level. On Drop, and on your desk—it’s tube time. Finally.”

Three Kilograms Worth Of Pre-Amp Power

Tube amps, much like Keith Richards, have never died.  They might have lapsed from the mainstream but they’ve always been around for those that love them, and are coming back into the fore.  You can’t really match the linearity and warmth offered by a series of tubes (or valves if you prefer) with a transistor nor will a purely digital source handle clipping with as much panache.  They never did catch on in motherboards but you can now find quite a few amps and pre-amps which use vacuum tubes and one of the latest companies to release such a product is from Drop.

The Drop + xDuoo TA-84 is the result of Drop partnering with the Shenzhen xDuoo Technology Co., Ltd. to add a little something old school to Drop’s audio lineup.  The staged release, including a steep discount on launch day, which they didn’t arrive in time for, suggest that Drop is somewhat worried about how well received the TA-84’s will be but after listening to them it isn’t clear what they are worried about.  If you have a serious pair of headphones from Sennheiser, Neumann or whichever your favourite vendor is, the TA-84’s are able to get the full range out of them.

Seriously Though, Don’t Get Your Greasy Fingerprints On The Tubes

Sure, it might sound like a joke but vacuum tubes get hot when in use and if you install the tubes without protection that could be enough to eventually pop them.  If you do not want that, use gloves or clean material to handle them and wipe them off occasionally, as all good things do come at a price.  Apart from that caveat the setup is easy, slide in the EL-84 power amp tubes and the ECC-82 pre-amp tubes, plug in the power, choose your source, your headset, and you are done.

There is a USB driver available but it is only needed if you plan on playing Direct Stream Digital (DSD) files; if you don’t know what they are then don’t worry about and if you do need support for them, we worry about you.  Your headphones pop in the front, or you can attach active speakers to the pre-out on the back.  Please do make sure to toggle the manual switch on the back to match which input method you will be using.  The gain switch toggles between high and low, depending on your preference.  It isn’t the easiest to reach but it is also unlikely you will need to access it frequently.  The knob is most impressive, it is a stepped potentiometer with the perfect amount of resistance when you are changing the volume and really helps make the TA-84 feel like a professional piece of equipment.


Massdrop And Sennheiser HD 6XX Headphones Are As Open As Can Be

One of the first things you’ll notice about the Massdrop x Sennheiser HD 6XX headphones are the open backs, which could make or break them for you immediately.  The velour ear cups are very plush and press against your ears with a fair amount of force, not uncomfortable at all but strange if you are used to looser fitting headphones.  The six foot cable is a little short for using with the Drop + xDuoo TA-84, as it will likely be sitting somewhere prominent but out of the way.  It’s not a major drawback but depending on the layout of your desk you may want to invest in something longer.

The open backs let you hear your environment underneath the music you are listening to and those sitting near you will be able to make it out as well.  At 300 ohms of resistance, you are going to need a serious headphone amp to get the most out of the HD 6XX and the TA-84 will ensure you can hear everything there is to hear.  If you don’t like anything about the default setup of the Massdrop x Sennheiser HD 6XX headphones they are extremely user serviceable.  You can disassemble them completely and replace the parts with other options if you like.

Warm Your Ears With Your Favourite Music

The Drop + xDuoo TA-84 is one of Drop’s less expensive tube amps but it is hard to tell from the quality of playback.  Tube amps made it big when the guitar was the king of instruments and it truly does show in it’s performance.  The TA-84 emphasizes the guitar and bass frequencies, though that is not to imply the vocals are muted in the least.  For electronic music you lose some of what the TA-84 was designed for, however the added separation has a wonderful effect on your ears.

The Massdrop x Sennheiser HD 6XX are a great match for this headphone amp, sitting at the lower end of the price scale for high impedance headsets.  They won’t cost you anywhere near as much as the Neumann headset that were the other headset available to test the TA-84 with, those are roughly triple the price.  If you do have a higher end set of cans, the TA-84 amp is still a great choice as it will bring out so much more than plugging them into a normal pre-amp.  That’s not to say you shouldn’t stick with the HD 6XX cans, they are stellar for their price point and an absolutely solid choice for anyone’s ears.

The TA-84 isn’t designed to work as a monitor, the tubes provide a warmth specific to that type of amp and not the flat sound curve you want from monitor speakers, earbuds or headphones.  If you love the sound tubes provide, then you should definitely keep an eye out for the next release which should happen in October.  The limited original run which Massdrop manufactured suggest they are a little worried about the size of the market for the TA-84, that they did sell out immediately suggests the worry might be unwarranted.  For the price, you get a lovely looking and very effective pre-amp for speakers or headsets, which can connect via USB or RCA without the need for extra software.  It seems an easy decision for someone in the market for an affordable tube amp.

a nice warm glow

A Glowing Conclusion To The TA-84 Tube Amp

Musical taste is as subjective as it gets, and there will be those with no interest in the qualities that tubes bring to audio.  On the other hand there are those of us old enough to recall the heyday of the tube amp very fondly.  The ability to bring that to the desktop for significantly less than the usual price offers an opportunity to the latter.

At roughly $300 the TA-84s are a bit of an investment, but not quite the expense of a pre-amp that costs the same as a decent GPU.  If you miss the warmth this style of amp provides, and don’t already have a specific model in mind, the TA-84 will let you do so without the pain a $1000 tube amp will cause you.  The style is also hard to beat, a large black metal casing, gently lit by the glow of the four tubes means not only are you listening to music the way you want, your desk will look a lot more stylish as well.

It has been a while since I’ve been able to enjoy the tones that a tube amp brings to my favourite music and I am grateful to Drop for the chance to experience it again.  Perhaps it’s time to consider putting this tube amp next to the FOSI.

Review Disclosures

This is what we consider the responsible disclosure of our review policies and procedures.

How Product Was Obtained

The product is on loan from Drop for the purpose of this review.

What Happens To Product After Review

The product remains the property of Drop but is on extended loan for future testing and product comparisons.

Company Involvement

Drop had no control over the content of the review and was not consulted prior to publication.

PC Perspective Compensation

Neither PC Perspective nor any of its staff were paid or compensated in any way by Drop for this review.

Advertising Disclosure

Drop has not purchased advertising at PC Perspective during the past twelve months.

Affiliate Links

This article contains affiliate links to online retailers. PC Perspective may receive compensation for purchases through those links.

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About The Author

Jeremy Hellstrom

Call it K7M.com, AMDMB.com, or PC Perspective, Jeremy has been hanging out and then working with the gang here for years. Apart from the front page you might find him on the BOINC Forums or possibly the Fraggin' Frogs if he has the time.


  1. Operandi

    Tube amps should be flat, any modern good one anyway. The “warmth” from tube amps is mostly due to their distortion profile (most popular working theory anyway), not from their response having a curve.

    Looks like an interesting amp but given the load limitations I’d probably recommend a Schiit Valhalla; its not much more and is made in the US.

    • Jeremy Hellstrom

      They do make good Schiit, can’t argue that.

  2. A Guy

    Some cheap tube amps have been caught using solid state amplification, making the tubes either purely decorative or a noise/distortion source that’s added into the sound.


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