April 14, 2020Audio Product Reviews

xDuoo TA-30 Review – A Box Full of Surprises

This review is posted here in partnership with Soundnews.net. It was originally written and published by Sandu Vitalie of Soundnews.net on Nov. 10, 2019.

A lot of time passed since I listened to an all-tube amplifier at my place. I still have good memories of my former WooAudio WA6 Special Edition that I was upgrading monthly with better vacuum tubes and better capacitors, just to squeeze the best out of it. That one was the only headphone amplifier that successfully tamed my former flagships: Sennheiser HD800 and Beyerdynamic T1. I was so hooked with the sound of vacuum tubes than even my R2R DAC had a tube output stage, it was called MHDT Havana. The overall experience was magical, enveloping and easy going. At that time, I was researching the inception of rock music and was listening to a lot of Elvis Presley and The Beatles that worked absolutely great with that particular setup. Time passed, tastes changed, my headphones changed and I didn’t have the chance to experience the same relaxing type of sound. When I tested the hybrid xDuoo TA-10 about one year ago, I got just a glimpse of what tube headphone amplifiers can accomplish. It sounded smooth, musical and relaxing but did not possess the strongest grip of the headphone drivers, sweet harmonics were there in smaller doses and the soundstage wasn’t as wide as with my long-forgotten WA6 SE.

When xDuoo released preliminary information that they are working on a DAC, preamp and headphone amp combo with stronger power output, with custom audio grade capacitors, with a rectifier tube and an all-tube design, I knew it would be something interesting to hear. Some weeks later I finally saw the final renders and it piqued my interest even further. And now, without further ado, I present their flagship DAC/Preamp/Headphone amp simply called xDuoo TA-30.

1. Unboxing

The unboxing experience is positive. Since it carries 3 sensitive vacuum tubes, some extra care was necessary when shipping. Those tubes are sitting in their own box full of foam. In the next box you’ll find two metal tube protectors or shields - call them as you like, a USB Type-B cable, a headphone adapter, and a very thick Bluetooth antenna. A power cable is located in another box and the bigger foam cage supports the unit itself. Underneath it, you’ll find a detailed user manual and a warranty card. Everything is secured and is sitting tightly. I didn’t find a Mini CD with drivers as I found in the TA-10 package. It seems that xDuoo listened to my advice and put those drivers online. Sincerely now, do you still have an optical drive on your PC or laptop? I don’t.

2. Design & Build Quality

TA-30 is not that big per se, but it is much heavier than it looks thanks to the oversized power transformer that is staying on top to better dissipate the heat and move the magnetic field farther away from the audio circuitry. I personally like it a lot more without the tube guards, it looks simpler that way and cold air should move easier around the tubes. At only 29 x 11 x 17 cm and weighing 3 kg, it can be easily integrated into any office or living room.

TA-30 is built to high standards, the top transformer cover is really thick and both the front and rear metal plates are thick too. The case is made out of machined aluminum alloy that reduces electro-magnetical interference and also works as a giant heat sink. I like that all the screws were moved underneath and on the back for a much cleaner look. TA-30 weight is supported by 4 tall rubber feet that will absorb micro-vibrations and will increase the cooling area for the unit. If you are putting the transformer, the driver and the rectifier tubes outside the unit, you can imagine that most of those units will look the same with just minor differences so there isn’t more to say about TA-30 in terms of looks.

3. Controls & Connectivity

xDuoo went with a much bigger display that offers better visibility and brightness and it is free of any LEDs that weren’t that cool on the TA-10. It will show you the selected input, the sample rate, and the PCM or DSD data stream. If Bluetooth input is used, it will show the exact codec it receives from the BT sender.

There are 4 buttons on the front: an Input selector with 5 positions, a filter button that is mostly set and forget, a BT button that will pair or unpair a Bluetooth source and a language button that has 2 positions: English or Chinese. The volume pot is an analog one, I like the look of the volume knob but I dislike how easy it turns the volume up and down. I would like a higher physical resistance, just be extra careful when you handle it because TA-30 is incredibly powerful even with the most demanding headphones. TA-30 is a single-ended amplifier, so the headphone jack on the front is a simple 6.35mm (1/4”) one.

On the back, it offers 4 digital inputs: USB, Coaxial, Optical, and Bluetooth. You can also use it just as a headphone amp or tube preamp if you use the AUX IN, or you can use it as a DAC + tube preamp or just as a preamp by sending the audio signal to a power amplifier by using the AUX OUT. Be warned that compared to TA-10, this one is not using a universal power supply, so it is either a 220V AC IN unit or a 110V unit, check the voltage bellow the AC inlet before you power it on.

4. Tech Specs

We are dealing here with a full input to output tube headphone amplifier and preamplifier, which also works as a DAC and as a Bluetooth receiver.

Digital to analog conversion is done by a single ES9038Q2M chip that in my opinion works a whole lot better with vacuum tubes than the former AK4490 from AKM. xDuoo went all-in with the digital processing, they used a high-performance Altera FPGA that I’ve seen in the Topping D90 DAC. It has 2 low-noise crystal oscillators that will better cover a wider sampling rate. The USB input duties are carried by the XU208 chip from XMOS that in my case was always stable and worry-free. Via USB, TA-30 is capable of decoding PCM up to 32 bit/768 kHz and DSD512 (x8). Elna Silmic II audio-grade caps are everywhere together with Nichicon FW caps, all sourced from Japan. xDuoo even developed their own metal polyester film caps that are working as coupling caps for the tube stage, things are getting really serious here.

As a Bluetooth receiver, TA-30 is using currently the best BT chip on the market, the CSR8675 from Qualcomm. This one is capable of receiving audio streams in SBC, AAC, AptX, AptX-HD, AptX-LL and LDAC codecs. If you are using an iOS device you will be limited to SBC and AAC and on Android, you can have all of them. LDAC is currently the best BT codec that is capable of sending up to 990 Kb/sec data streams so most of your 16 bit lossless PCM files will be received as an exact copy of the original file. Can TA-30 be considered as a streamer because of that? Not really, because higher resolution PCM can’t be sent as bit-perfect and some minor micro-details and frequency extension will be lost along the way.

As for the amp section, TA-30 is using two current production ECC82 double triodes made by JJ Electronic. There are plenty of substitutes for ECC82 tubes as 12AU7, B329, CC82E or 13D8 and all of them are compatible with it. If one of the tubes will fail, you need to change both of them with a matched pair of tubes, otherwise, one tube will have higher emissions and it will sound louder in one channel (on Left or Right). There are tons of current production ECC82 and 12AU7 tubes from the likes of JJ, Electro Harmonix, Ruby Tubes, TAD, Genalex, Sino, Pavane, and many others.

Power rectification is made by a 5Z3P tube with an xDuoo logo stamped on it, I’m not really sure who made this one. There are few substitutes for 5Z3P as 5U4G, 5U4GB and again there are many manufacturers that are making them. If you want the best rectifier for your TA-30, look no further to the likes of Psvane, KR Audio, Emission Labs, Ayon, and NOS Western Electric but be prepared to pay some pretty pennies for those. I had a single Emission Labs 5U4G Mesh-Plate rectifier in my WA6 SE and it cost me about $400 apiece…I’ll stop here.

If you are chasing for a warmer sound, with sweeter harmonics and a smoother presentation then I strongly recommend hunting for some NOS (New Old Stock) military-grade tubes made before the Cold War era. I especially like older Mullard, Sylvania, RCA, and Western Electric tubes.

As a headphone amp, it will offer a whopping 3000 mW (3 Watts) of power into 32 Ohm loads, but since it has a +16 dB gain that can’t be changed with a lower value, forget about listening to IEMs with this one. It gets way too loud way too fast with IEMs and even with my portable headphones. TA-30 was developed to drive super heavy loads as high impedance and thanks to the output transformer it will power nicely even low impedance and low sensitivity headphones. It drives a pair of Audeze LCD-4 at less than half volume as if it’s nothing, so I’m pretty sure it can drive anything you’d want, even a pair of Hifiman Susvara, HE-6 or Abyss AB-1266.

5. Sound Performance

5a. Burn-In requirements & Safety Precautions

Since TA-30 is full of high-grade Nichicon and Elna electrolytic caps and with some fat metal polyester film caps, plus that oversized transformer, it was mandatory running it in for at least 100 hours. As silly as it sounds, those driver tubes and the rectifier tube also need some burn-in, it is recommended at least 48 hours before making any critical listening. Another interesting fact is that TA-30 will sound at its best only after about 15 minutes of warm-up. I put TA-30 for a 7-day burn-in connected to a laptop that was playing tunes on repeat. I only turned it off at night since it is really hot to the touch after about one hour.

At first, it sounded closed-it, it was on the hotter side with brighter treble, there wasn’t any spaciousness, dynamics felt forced and really stiff. One week later, there is nothing of that left, spaciousness and transparency improved the most, the bass made its appearance and finally it is sounding easy going and smooth.

Having a higher gain and an impressive power output, TA-30 is on the hotter side if you crank that volume up. When I’m listening to Audeze LCD-4 at 11 o’clock position, TA-30 is hot to the touch, so I do not recommend putting it on top of another audio equipment, in direct sunlight or in tighter spaces. It should be used only in a dry and cool place with some extra room between it and other equipment. Please check the user manual and read the “Safety Directions” for a clear explanation.

5b. Sound Signature & Tonality

After a painful week of waiting, I finally sat down and took a serious listen. In its stock form, it lacks brightness, sounds warm and inviting, it is easy going with light acoustic music and engaging with faster-paced music. It sounds a whole lot sweeter than my usual all discrete transistor-based amplifiers, it carries more emotion and sounds meatier almost all the time. Hearing the background noise of older recording as The Beatles, Elvis Presley and Led Zeppelin wasn’t as painful and distracting as it was on my Benchmark HPA4, its intensity was the same but it was softer and didn’t bother me at all. Transient response is just by a hair softer and the notes were rounded sounding somehow. Drums and cymbals sounded clear, natural and right, yet free of any over-sharpness.

If your music is grainy sounding, too processed, involving and rough around the edges, then TA-30 works like a magic pill for that kind of music. Any record I would listen to, TA-30 was like caressing my ears with smoother notes and sweeter harmonics. String-based instruments had a touching vibration, it was longer than on my solid-state electronics. Music had more volume, it sounded bigger, deeper but without putting a foot in front of dynamics. It left quite a positive first impression on me.

I’m extremely glad than xDuoo chosen an ESS Sabre DAC for this unit, it helps a lot with the tonal balance, with the speed, impact and overall cleanness. I feel that a different chipset from AKM, Wolfson or Analog Devices would make it too syrupy, too warm and would hide away some details, tilting the tonal balance too much. The overall package of an ESS Sabre DAC + an all-tube amplifier works wonders on some music and few particular headphones will be literally transformed into something else. Sennheiser HD700, HD800 users, all Beyerdynamic and AKG users should put a hawk-eye on this one, it’s worth a shot.

5c. Bass

I imagined that TA-30 will not really work with electronica and faster-paced music. Since LCD-4 by Audeze is notorious at detecting weak dynamics and lazy bass, I fired some Infected Mushroom – Return to the Sauce (2017) and closed my eyes. In the next moment, the LCD-4 was slamming me with enormous energy in the bass that was going really low. In terms of dynamics and slam, TA-30 is performing above my expectancy level and actually impressed me the most in this department.

TA-30 offers just a bit of bloom in the bass that makes it voluptuous, it envelopes the whole listening space and feels heavier than usual. The only things that were rendered differently compared to Benchmark HPA4 or Kinki Studio THR-1 were the speed of the bass and how much time it lingered around. Solid-state amps had it faster but short-lived, on TA-30 it would remain just a fraction of a second longer, will pulsate deeper and will leave a bigger stain on the music.

All in all, bass response is one of the strongest traits of this unit, it will go low, it will be maintained and it will impress a bass addict.

5d. Midrange

The absolute best part of TA-30 in terms of frequency is that magical midrange. If acoustic, instrumental music or anything that has to do with musical instruments and voices is part of your audiophile diet, then it will impress from the first minute of pressing play. TA-30 will decompress all that music and then will add a vivid filter all over it. TA-30 puts a much bigger accent on musical involvement and less on the technical aspect. TA-30 doesn’t want to impress with an ultimate detail or sharpness, it is against those and chooses a mellower and calmer approach to music reproduction. If on solid-state amps I am hearing a very clear outline and leading-edge, with TA-30 I am hearing the core of the notes, their innards, it’s weight and texture. Those sweeter harmonics are at play here and TA-30 will just offer higher contrast and a more vivid musical experience. TA-30 doesn’t want me to analyze my music, it relaxes me and compels me to listen and forget about the technical aspect of everything.

5e. Treble

I started listening to Mark Newman – Until the Morning Comes (2010, Walls of Jericho) and couldn’t believe how clear is the drum kick and how sparkly are those cymbals. I expected it to be recessed and shy but that was not the case with TA-30. I heard it well extended, sparkly but still natural, smooth and present even at the top octave.

Listening to Who You Are by The Inoculated Canaries (2018, Hypocrite) I’ve felt a serious thump of the drums, slam was great and again those cymbals sounded so clear and defined, I checked my gear and yeah, I’m still listening to TA-30. I could easily focus only on the treble region with the open wide nature of this unit. I wasn’t expecting to say this but it has a great treble extension and I can only imagine how it might sound with some better tubes.

5f. Transient Response

Listening to simpler music like Mason Murphy – Let it Rain (2019, Self-Released) I’ve heard an impressive slam and punch. That bass guitar and those electric mixes moved so much air around that I involuntarily started nodding my head and toe-tapping my feet. Combine a good slamming amplifier with a transient monster as Audeze LCD-4 and you can already imagine that I was high in the clouds, just a very pleasant experience.

Moving to industrial music as Rammstein – Deutschland (2019, RAMMSTEIN), TA-30 was capable of keeping up with those faster beats, quickly executed guitars and that crowded electronic mix sounded as fast as I know this song on class-A amps like Kinki Studio THR-1, Burson Conductor 3, Audio-GD D-28 and just by a hair slower compared to Benchmark HPA4. I especially liked that TA-30 was decompressing the song first, it would increase the void space between the notes and only after that it would playback everything. It was much easier for me to discerning everything that happened in this song compared to solid-state amplifiers.

The ultimate attack is great and it has some exploding dynamics, decay is also unusually fast for a tube amplifier offering a livelier approach. It was just by a hair slower compared to best solid-state amps.

5g. Soundstage & Depth

Up until this point, as a headphone amplifier, TA-30 took the spot as the widest sounding headphone amplifier. It just outperformed the Kinki Studio THR-1, Burson C3R, the Audio-GD D-28, and even the Benchmark HPA4 in terms of depth and stage. Any headphone I would connect, it will show me their limits in terms of soundstage size. I didn’t know Audeze LCD-4 and Erzetich Phobos could sound so spacious, deep and wide. Hell, even Hifiman Arya with its narrower stage was sounding much wider from left to right. I found additional layers especially in the midrange, voices sounded expansive and deep, even the recording room was increasing in size. My on-stage rock and cozy jazz sounded wider and deeper I as remember them to be.

5h. Detail Retrieval

It was wise putting an ESS Sabre 9038Q2M DAC inside, an Altera FPGA and two low-noise crystal clocks because they all played a big role in achieving a clean output that is free of any harshness or distortion. TA-30 is grain-free all the time, quite transparent and detailed sounding too. Normally with a solid-state amplifier, the music is presented from left to right in a 2D plane with few things that are happening around, those are adding holography and a clever note placement around the listener for a pseudo-3D feeling. TA-30, on the other hand, is always so 3D sounding, very holographic, deep and in the process becomes a transparency beast. It is a clear window to music and I just get lost in my music with it.

However, if you use sensitive headphones, there is a gentle and barely audible hum at low-level listening. It is decreasing in intensity once you go higher on the volume wheel so, at the normal listening level, I am unable to spot it even with my portables.

If the last bit of resolution and ultimate detail retrieval is important to you, then you might want to look elsewhere as the main goal behind it was something else.

5i. Wireless Performance

Connecting a smartphone to it is really easy, just select the BT input, enable BT on your phone, search for “xDuoo TA-30”, connect to it and that is it. My smartphone is BT 5.0 enabled, AptX-HD and LDAC compatible so it should be the perfect BT sender in this case. For starters I will mention than TA-30 has the longest and the thickest Bluetooth antenna I’ve seen so far, all other BT enabled devices as Topping DX7 PRO, D50S, D90, and Burson Conductor 3 Reference had a thinner and a smaller antenna. With xDuoo TA-30 placed in my office (just at the entrance of the apartment) I was simply unable to lose the signal from any room. Even with 3 thick concrete walls and a 15-meter distance, the Bluetooth signal was strong and I didn’t lose a single beat. So far, compared to all other BT enabled devices, TA-30 offered the strongest and the most stable signal. The Bluetooth antenna works as a wireless amplifier so it all makes sense now. In a four-room flat, xDuoo TA-30 performed flawlessly connected to my smartphone and streaming lossless music from a Tidal subscription.

What was even more amazing is that all the lossless CD-quality music I streamed from Tidal sounded exactly the same as with TA-30 connected to my PC and playing the same lossless tracks from Tidal. TA-30 can really work as a powerful wireless setup without the need for a computer or music source.

5j. Power Output

xDuoo has one of the most powerful headphone amp sections I’ve tried. I consider Audeze LCD-4 and Hifiman Arya really inefficient headphones, yet with LCD-4 I could go up to 12 o’clock where I could resist just for a minute. My usual listening level would be somewhere between 10:30 and 11 o’clock position. With Hifiman Arya between 9:30 and 10:00 is my normal listening level. I don’t know what was on their minds, if they wanted to drive every headphone in existence with a single unit, then they succeeded.

The culprit is not only those 3 Watts of power into 32 Ohms but the hotter gain of +16 dB that suggests using it only with desktop, low sensitivity or high impedance headphones. I wish it had a fifth button that would lower the gain setting, a 0-dB unity gain would be just perfect with IEMs and portable headphones. Even some desktop-class headphones don’t need huge amounts of power to be moved as Focal headphones and Grado.

I’m glad to report that with all planar-magnetic headphones that I have at my disposal, TA-30 was driving them with amazing control and grip. I never felt that they needed more power and as much as I stressed it, it was like a walk in the park for it, even crowded passages or high dynamic swings were easy tasks for it.

There is one drawback of using a high gain of +16 dB, you should forget about using sensitive IEMs with it, even some portable headphones could be over-driven. For fun, I connected the Moondrop Starfield IEM and even on the lowest volume position I was hearing the music and a low-intensity hum. Most of the analog volume potentiometers, including the one inside TA-30, will not have a perfect channel balance from 0 to 5% of volume and this is the exact volume range you will have with IEMs and with sensitive headphones. Past that volume level, the channel balance is perfect but it’s already way too loud for sensitive headphones and IEMs. This is the only serious drawback of TA-30, but in all seriousness when you consider a desktop tube amplifier like this one, you consider it for your bigger and harder to drive headphones and not for your portables.

6. Conclusion

It is built to last and looks clean without brave design decisions. As a DAC/Headphone amp combo, it is among the most powerful units I had the pleasure of testing, it will drive even the heaviest loads I know with an ultimate grip and driver control. It is easily in the top 3 most powerful headphone amps I tested and no matter the music I would listen to, a huge power reserve will always remain on tap.

The jump from TA-10 to T-30 is much bigger than I anticipated, everything was improved to unrecognizable. Soundstage improved tremendously; it was simply the widest I encountered with my headphones. It had an incredible slam and control in the bass, the midrange was sweet, engaging spread-out and layered. I’ve heard the most natural voices on this unit and weirdly enough, the treble never felt recessed or having a lower quality. Even top octave was there with sparkle and zing. That Sabre DAC added much-needed detail, leading-edge and speed that was shy and unimpressive on TA-10.

Considering that TA-30 is an all-tube design, I expected a slower and a mellower tonality, but xDuoo managed to impress me with a neutral, transparent, energetic and faster sound presentation. It borrowed some of the greatest stuff from solid-state amplification and added some tube goodness on top.

Accounting for everything it does right, $710 seems like a small price to pay for the greatness that awaits.