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Introducing Drop + Xduoo OTL Tube Headphone Amp

We’re excited to announce our first collaboration with xDuoo—and our first-ever OTL tube amplifier. Building on xDuoo’s extensive product line and solid reputation in the amplifier space, we worked closely with their engineers to create a brand new tube amplifier designed to pair with high-impedance headphones like our ever-popular HD6XX and HD58X. It’s the Drop + xDuoo OTL Tube DAC/Amp—and it’s totally tubular. 
From the earliest designs, we intended the amp to pair with high impedance headphones of 120 ohms up to 600 ohms. For this reason—among sonic preferences—we chose an Output Transformerless (OTL) topology for the amp, since it pairs so well with high impedance loads. Many fans of OTL amps such as the Darkvoice 336 and Bottlehead Crack are well aware of the magical attributes these amps can have when paired with a suitable set of cans. The tube configuration uses a total of 4 tubes (2 per channel). For the preamp tubes, we chose the ECC 82 (equivalent to the 12AU7), which has been widely used in many popular tube amps. The power tubes are EL-84 pentodes, which had originally been conceived for use as a higher sensitivity output tube in radios. (These classic tubes are also where the TA-84 gets its model number.) An added benefit for those who like to swap tubes: both the ECC-82 and EL-84 tubes are in current production from several tube manufacturers for a broader option of tube rolling possibilities. To deliver both accuracy and precision in volume adjustments, the amp uses a stepped potentiometer for volume control. A typical potentiometer generally uses some type of strip of resistive material, with a wiper to slide across it in order to provide variable output levels. A stepped potentiometer, by contrast, uses a series of switches, with each position having a specific value of resistor to achieve different levels of output. The main advantage of this design is a greater degree of channel balance and reliability. Alongside this potentiometer—or rather, on the other side of it—we’ve also included a gain switch on the rear of the amp to allow for further increase in control of the output level. For those that want an all-in-one signal package, we’ve also equipped the amp with a built-in DAC to handle conversion with rock-solid resolution. The ES9018K2M Reference DAC is engineered to handle 32-bit 384kHZ PCM bit rates for seamless playback.
Finally, we’ve outfitted the Drop + xDuoo with a preamp output, giving you the flexibility to use it as a preamplifier in other systems. Connect it to your Flagship monoblock power amplifiers, or as your volume control for your BMR1 monitors. Anodized with a sleek black finish—and small enough to slot into any corner on your desktop or shelf—it’s the perfect addition to any signal chain in need of a tube treatment. The Drop + xDuoo OTL Tube DAC/Amp will be here in no time. Hit “Request” to be the first to know when it launches.


This seems very similar to the TA-03s with an updated DAC and non-Russian tubes. If so, I would imagine it sounds fantastic with the HD-6xx's.
Sep 19, 2023
Need to know more about the volume control. How many steps does it have? Hopefully it's not just 24 as that usually gives too much difference from one step to the next.
Sep 19, 2023
this could be the best drop since grace design.
Sep 17, 2023
I really hope this supports 100v (Japan).
Sep 16, 2023
Glad to see a "gain" switch. I've had an XDuoo all in one for years. It desperately needs a high gain setting for many cans. The 9038 dac chip is one I'm familiar with. When implemented with proper supporting circuitry I can certainly live with its sound. If it ain't priced like it contains magic inside the tubes, I'd be interested. I have MQA dacs. It's support or lack thereof doesn't mean a thing to me.
Sep 16, 2023
Will it suport a 3.5 4 pole headphone cable
YodastienThe amp uses a single ended 6.3mm TRS output.
Sep 15, 2023
So how is this different from the TA-30? I am interested but it seem like the TA-30 with less features. Help me understand.
RilchuTA-30 uses a hybrid topology which where the TA-84 is an OTL circuit which is completely different, although both incorporate the use of tubes. If you plan to use low impedance headphones like Planars then you would want a Hybrid amp like the TA-30. OTL amps like the TA-84 work best with high impedance headphones such as the 6XX which is 300 ohms.
Sep 16, 2023
T.FernandezThank you for helping me understand better.
Sep 15, 2023
lo siento but i’m broke 🥴
Sep 19, 2023
All of them. Either because the maker is paying more for the chip that is more expensive because the chip manufacture has to pay for the unfolding code license or the maker must purchase the code license directly from MQA if they are building in-house.
Sep 21, 2023
dwane5Wow. you're late to the game, Dwayne. MQA's 15 minutes is over.
Sep 15, 2023
Very interested in this. xDuoo does some good work with OTL.
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