Excellent build quality, Smooth notes delivery, structured and coherent midrange, very spacious soundstage, drives high-impedance cans with aplomb
Background noise evident on more sensitive gear, High OI limits many pairings, Not the most detailed sound, struggles with low-impedance loads
Combined with a set of high-impedance cans, it makes for a reasonably priced, truly unique and romantic listening experience that you’d be hard pressed matching with other amp types.
Tube amplifiers are quite an alluring proposition. They simply conjure great imagery, and few can deny the appeal of a warm, syrupy analogue sound. With that said, solid state amplifiers have become rather ubiquitous for good reason, the latest crop of releases especially are so flexible and powerful, it has become difficult to make a case for tube amps in the modern day. For all intents, they are considered obsolete by most. And, for those that find their colouration and distortion appealing, hybrid solutions with solid state output stages are considered to offer the best of both worlds. Why then, has xDuoo released an OTL, all-tube driven amplifier in 2021? OTL tube amplifiers drive headphones in a very different manner to solid state ones. In certain circumstances, their weaknesses can become unique positives. The TA-26 represents xDuoo’s take on the base design that has been assumed by many including Darkvoice. The company has realised this with modern components such as ELNA SILMIC film capacitors and NICHICON filter capacitors that provide tighter tolerances than regular, non-audiophile units. The result is a respectful reimagining of a beloved, time-tested tube amp design.
The TA-26 retails for $319 USD at the time of writing. You can read all about it and treat yourself to one on Apos Audio!
I would like to thank John from Apos Audio and the team at xDuoo very much for reaching out and for providing me with the TA-26 for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the amplifier free of charge, I will attempt to be as objective as possible in my evaluation.
- Page 1: Unboxing, Design & Usability
- Page 2: Sound, Pairings & Verdict
The TA-26 has a barebones unboxing experience though I can’t complain as this is a simple device and on the affordable side for what it is. The box is large with thick foam padding that keeps the amp and delicate glass tubes safe during shipping. The amp and tubes are separately packaged with cables in a separate box. xDuoo includes an IEC power cable and 2.5mm to 6.3mm adaptor for headphones. No RCA cables are included, but otherwise, nothing else is required to operate the amp.
I do feel the images I’ve seen of this device online didn’t do the TA-26 justice; the mismatched face and end plates certainly didn’t prepare me for such a rigid and well put together design. The TA-26 emanates an industrial vibe; a fusion of sound and machinery with its stainless-steel rails and gritty gunmetal housing. It is tall due to the protruding tubes and transformer block and quite long but very slim, which makes it ideal for placing next to your monitor for instance, if not stacking. The first aspect that strikes out of the box is the amplifier’s weight which, alongside its thick all aluminium alloy shell, provides an impression of great quality. The aluminium itself has a more aggressive sand-blasted finish than most, and you can tell xDuoo invested in a few additional CNC passes here due to the smoothness of each edge, cut-out and abundant chamfering. Of course, we can’t forget the gentle glow of its dual pre-amp and buffer tubes that, as on most tube amps, form an alluring centrepiece.
The rails serve little purpose but do contribute handsomely to the aesthetic without being too loud. Speaking of which, undoubtedly, focus is drawn to the saturated red volume knob which also contributes to a somewhat old-school aesthetic. It too shares an aluminium construction with tactile knurling all around. The pot is smooth and was free of noise during testing with a nicely weighted action. There are abundant vents throughout the device which coincides with the company’s recommendation to give the amplifier some surrounding space to allow for heat dissipation. In terms of IO, the TA-26 is a simple device with only single-ended connectivity and pass-through for speakers. This is done via a pair of RCA connectors on the rear and a ¼’ headphone jack on the front. Also on the front is the power switch and a blue status LED and power is delivered by a generic 3-pin IEC cable meaning it is easy to swap this out to adjust the length.
Setting up the TA-26 is as a simple affair given its straightforward IO and generally limited feature set. This is a pure headphone amp experience with no superfluous additions. As on any other amplifier, simply connect your DAC to the input via RCA and plug in your headphones. Should you want to run speakers, they can be connected via the pre-amp output adjacent to the input RCA plugs. The preamp section does run through one of the tubes which will provide a warm, sweet tone to your speakers too. Insert the tubes into their respective ports, the connectors are keyed so they can only be installed in their correct orientation.
Once power is connected, you can power on the amplifier, audio gently fades in as the tubes warm up and this process takes about 15 seconds. The same goes for powering off the amplifier. Of note, there are no added noises, pops, etc during either power up or down. In addition, the volume pot introduces no additional noises during adjustment. Another thing to note is that the entire amp does get quite warm to the touch during use so I would definitely adhere to xDuoo’s recommendation to provide ample surrounding space for heat dissipation. The tubes themselves do get warmest but never to the extent that you would burn yourself, even after a few hours of use.
The TA-26 is a dual tube design, the larger being the 6N5P power/buffer tube, the smaller in front being the 6N8P pre-amp tube. Both are swappable, allowing the user to sizably alter the sound characteristics of this amplifier either at additional cost of tubes or if you already have these components. This has always been a hugely appealing aspect of tube amps and, as this is a purely tube-drive amplifier, you will notice large changes with different tubes. These can be purchased easily online.
As an aside, I did note that the power supply isn’t especially well-isolated. While it is impressively clean most of the time, I noted that the TA-26 would pick up hum from the powerlines, and this was exacerbated once the device was warm and in sustained use during longer listening. This means that, if possible, you should give the TA-26 it’s own power point rather than running it from a power board, especially if other audio equipment is connected. Under such conditions, the unit being tested exhibited zero noise.