Reviewers' ChoiceAt Audio Video Show 2019, in Warsaw, Poland, Peter Lyngdorf sat down to chat with Doug Schneider, publisher of the SoundStage! Network websites. Of the many audio brands he’s been associated with over the years, Lyngdorf is probably best known for having founded TacT Audio and, in 2005, Lyngdorf Audio. Both companies produced the Millennium, an amplifier that was ahead of its time when it was launched in the late 1990s. Throughout its long production life the Millennium featured two proprietary Lyngdorf technologies: Equibit pulse-width modulation (PWM), RCS speaker equalization, and, later, the RoomPerfect room-correction system.


A couple of years ago the Millennium was discontinued and replaced first by the TDAI-2170, which is still available, and now the more powerful TDAI-3400 ($6499, all prices USD), which Lyngdorf was promoting in Warsaw. The TDAI-3400 includes the latest versions of Equibit and RoomPerfect, with options available for a high-end analog input module with upgraded analog-to-digital conversion ($400), an HDMI module with three inputs and one output ($400), or both boards ($700). Being a fan of amplification components that include a built-in DAC and room correction, I was glad to have an opportunity to review the TDAI-3400.


The Lyngdorf Audio TDAI-3400 is a feature-rich product. I can think of many amplifiers that take advantage of newer types of amplification circuitry, such as class-D, and several integrated amps and preamps that include room-correction systems, but very few that have both. Arcam’s latest integrated amplifier-DAC, the SA30, employs Arcam’s own class-G amplification and Dirac Live room correction, but in the TDAI-3400, the amplification and room-correction systems were both developed by Lyngdorf. But, of course, just because a company produces and uses its own technologies doesn’t guarantee that those technologies are any better than other companies’.

Lyngdorf Audio specifies the TDAI-3400’s power-amp section as able to output 200Wpc into 8 ohms or 400Wpc into 4 ohms by using extremely rapid-switching, low-Rds MOSFETs, and to provide a maximum current output of 40A. Although Equibit, Lyngdorf Audio’s version of the PWM switching technology, is proprietary, other companies make PWM amps -- less usual is how Equibit controls the output volume. Instead of attenuating the analog signal after it goes through D/A conversion and is sent to the power-amp stage, the signal is sent directly to the power amp while still in the digital domain; the volume control then adjusts the voltage output of the power supply, which regulates the amount of power sent to the loudspeakers. Lacking a traditional DAC or preamplification stage, the TDAI-3400 has much simpler circuitry and acts as a power-DAC, which makes it theoretically less susceptible to noise and distortion -- the digital signal is not converted to analog until just before it’s sent to the speakers.


While the TDAI-3400’s amplification section and DAC -- or, to be more precise, lack of a traditional DAC -- are technologically impressive, I was more intrigued by Lyngdorf Audio’s RoomPerfect. This room-equalization system has been around since 2006, used in later versions of the Millennium integrated-DAC and Lyngdorf products as well as in several components from McIntosh Laboratory. I once heard a very convincing dealer’s demo of RoomPerfect using McIntosh preamplification in which two big floorstanding speakers were placed asymmetrically along one long wall of a relatively narrow room. Even with this less-than-ideal positioning, the bass was tight and controlled, and the very stable imaging of the vocalist was centered directly between the speakers. The memory of this demo has stuck with me over the years -- I was eager to hear what Lyngdorf Audio’s latest version of RoomPerfect could do with my own listening room.

The TDAI-3400 comes equipped with a high-quality calibration microphone with cord and stand, and with the RoomPerfect software built in, and updatable by the user via the Internet or USB. The mike plugs into the front panel via a provided XLR-to-miniplug adapter.

In addition to RoomPerfect, the TDAI-3400 has bass-management settings for the main speaker outputs and the analog line-level and digital outputs, if subwoofers are used -- all of these must be set manually. The crossover frequency can be set as low as 20Hz, and the high- and low-pass filters can be set to Linkwitz-Riley (second, fourth, or eighth order) or Butterworth (first, second, or fourth order). The main speakers can be specified as various Lyngdorf speakers, which activates built-in equalization settings for those models, or custom EQs can be set based on user preference. I didn’t use any EQ settings with my speakers.

The standard version of the TDAI-3400 has two sets of analog stereo inputs (RCA) and seven digital inputs: two coaxial (RCA), three optical (TosLink), one USB Type-B, and one AES/EBU (XLR). The XLR and RCA inputs support data up to 24-bit/192kHz, the TosLinks to 24/96, and the USB to 32/384 and DSD128.


The TDAI-3400’s outputs comprise line-level stereo (RCA, XLR), digital coax (RCA), one pair of five-way speaker binding posts, and, on the front panel, a 3.5mm headphone jack. Other connections include control interfaces for DB9 RS-232, Ethernet, USB Type-A, a slot for a microSD card for backing up system setup configurations, and a 3.5mm, 12V trigger input and output. Next to the IEC power inlet are the main power rocker and a switch for selecting between 120V and 230V.

The optional HDMI in/out board has three inputs and a single output, all of which support HDMI 2.0a, ARC, CEC integration, and PCM up to 24/192. The optional analog input board adds three pairs of single-ended (RCA) and one pair of balanced (XLR) inputs, as well as an AKM AK5394A chip for better A/D conversion, for those with high-quality analog components.

Measuring 17.7”W x 4.1”H x 14.1”D and weighing 18.1 pounds, the TDAI-3400 has a stately look in its finish of textured matte black. A large black-and-white display takes up much of the left side of the front panel, and provides access to all setup options. To the right of this screen and moving rightward are: a small Source/Menu knob, to access the menu system; a USB port for media playback; 3.5mm minijacks for the calibration mike and headphones; a big, heavy dial with a luxurious feel that adjusts the volume in increments of 0.1dB; and, in the lower-right corner, a tiny button for toggling between standby and on. The TDAI-3400 seems quite solidly built.

The very long, slender remote control is easy to hold, and includes buttons for the menu system. There’s also a remote-control app, which I installed on my Android smartphone. It was handy, but I didn’t use it much -- I connected the TDAI-3400 to my home network only when I wanted to access the setup options with the web-based interface. While setup is possible using the front-panel display and the remote, I strongly recommend using the web-based interface -- it’s far more intuitive, fast, and easy to use when managing the TDAI-3400’s many setup options.


The TDAI-3400 has many other features: Wi-Fi and Bluetooth connectivity, and support for Apple AirPlay, Spotify, Internet Radio, DLNA (uPnP), local file playback over USB, and a theater-bypass mode. However, I did take advantage of its Roon Readyness. Overall, I was extremely impressed by the integration of a comprehensive set of features into a well-executed, relatively user-friendly product that functioned without bug or fault throughout the evaluation period. My only criticism is of the TDAI-3400’s relatively short warranty: just two years.


I used the TDAI-3400 with my usual reference system. The main source was a Lenovo laptop computer running Windows 10, Roon, foobar2000, and Qobuz. I also used an Oppo Digital UDP-205 4K UHD universal BD player connected with Clarus Aqua Mk.II balanced (XLR) interconnects, to assess the TDAI-3400’s optional high-end analog input module. Speakers were MartinLogan Masterpiece Classic ESL 9s, connected with Clarus Aqua Mk.II speaker cables. And I used the Lyngdorf’s analog outputs to hear how well it could integrate into the system my two JL Audio E-Sub e112 subwoofers.

Initial setup was relatively painless. I downloaded and installed on my computer the USB driver, and connected the system to my home network via Ethernet. Using the web-based interface, I easily accessed all setup options -- it was similar to setting up a surround-sound processor -- including setting speaker types and distances, then running RoomPerfect’s calibration process.


Running RoomPerfect with just the MartinLogan ESL 9s was easy. I placed the calibration mike at my primary listening position, directed it toward the speaker side of the room and then, per the instructions, began the process of taking readings at random positions and orientations throughout the room, including near the room boundaries. I did this until, after about seven measurements, the system indicated that it had the required minimum level of “RoomKnowledge” -- i.e., more than 90% -- to conduct a calibration. For best results, Lyngdorf Audio suggests continuing to take readings until the RoomKnowledge is >95%. I did that later -- you can add measurements to a speaker profile at any time.

Because the TDAI-3400 allows the saving and storage of a second calibration, I conducted one, this time with my two JLA subs in the system. Before doing that, I had to set the bass management. After a bit of experimentation, I selected second-order Butterworth filters, as recommended in the TDAI-3400’s owner’s manual, and a crossover frequency of 70Hz. One advantage of RoomPerfect claimed by Lyngdorf Audio is that, having measured the performance of each speaker in conjunction with that of each subwoofer, it can then create a seamless blend of the speaker and subwoofer outputs. Once I’d saved the two speaker setups, I could easily switch between the system with subs and without, and easily turn RoomPerfect on and off via the web interface or the remote-controlled menu system. And although I didn’t use the additional EQ feature provided, I can see how some users might appreciate the ability to tweak the sound even more by boosting or suppressing particular frequencies.

Showing some TacT

When I received the Lyngdorf TDAI-3400, I first set it up with an old Cambridge Audio DVD-Audio player, just to ensure that it was functioning properly. Even before using RoomPerfect, it was clear that this was a powerful and wonderful-sounding amplifier. Listening to Robbie Robertson and the Red Road Ensemble’s Music for The Native Americans (CD, Capitol), I was struck by how well the amp controlled the deep bass, which was reproduced nearly fully by the two 8” woofer cones in each of my two MartinLogan ESL 9 hybrid electrostatic speakers, which are missing the lowest octave. Although the MLs require a fair bit of power to sound their best, the Lyngdorf was able to drive them without running out of steam, or sounding muddy or shrill at high volumes. The imaging of the women’s voices of Ulali in “Mahk Jchi” was holographic if slightly laid-back, while the Native American drumming of “Akua Tuta” was supertight, each beat well delineated from the next, and the voices slightly more forward than in “Mahk Jchi.”

As good as the Lyngdorf sounded on its own, my recollections of that RoomPerfect demo of years ago, and my experience of using Anthem Room Correction (ARC) for more than a decade in my reference two-channel system, told me that it would probably sound even better when I switched in RoomPerfect. Sure enough -- when I did, almost everything cleared up just a bit, from the lowest bass to well into the midrange and beyond. The aural images of individual instruments and voices were now crystal clear, with no audible distortion or smearing of images. Without the slight midrange haze that’s audible in all but the very best systems, the treble was now ultraclean but still smooth.

To test the amazing clarity provided by RoomPerfect, I cranked up one of my favorite reference rock tracks, “White Wedding (Part 1),” from Billy Idol (24/192 FLAC, Capitol/HDtracks). While some of the very bottom end was missing -- I still hadn’t turned on my subwoofers -- the electric-bass line was still very well defined and separated from the kick drum, and Idol’s snarling, sneering vocal was perfectly front and center. His even more palpable vocal in “Dancing with Myself (RAC Remix),” from Vital Idol: Revitalized (16/44.1 FLAC, Capitol/Qobuz), was pushed slightly more forward -- a characteristic of this recording -- and Idol’s voice was now so tangible that it was one of the most realistic reproductions of a human voice I’ve heard in my room. Even at very high volumes, the control the TDAI-3400 exerted over my ESL 9s was nearly on a par with that of my reference rig of Anthem STR preamplifier ($3999) with ARC Genesis room correction and Anthem M1 monoblock amplifiers (1000W into 8 ohms, $3750 each). The diminutive TDAI-3400 could run with the big boys and more than hold its own.


RoomPerfect has two filters: Focus optimizes the sound at the listening position, while Global improves the sound throughout the room. As I switched between the filters, Sting’s My Songs (24/44.1 FLAC, A&M/Qobuz) sounded more dimensional with Focus. Cheb Mami’s swirling backing vocal in “Desert Rose,” and Sting’s own overdubbed voice in “Englishman in New York,” had great depth. When I switched to Global, both lost not only depth but overall soundstage size. Deactivating RoomPerfect altogether flattened out the sound even more, most of the music now seeming to come from roughly the plane described by the speakers’ electrostatic panels. Switching back to RoomPerfect Focus opened up the sound again, the soundstage deepening by coming farther toward me and extending farther back, while also growing wider and higher.

The TDAI-3400’s 200Wpc and room correction impressed me with their ability to control my hybrid electrostatic speakers, but went to a whole other level when I switched in my two JLA e112 subwoofers. Using RoomPerfect’s calibration of the sub-sat system, saved as Speaker Setup 2, I swapped the subs in and out simply by selecting Setup 2 in the menu or web interface, the TDAI-3400 each time taking a few seconds to effect the transfer. With the subs in and RoomPerfect set to Global, I really cranked Billy Idol’s “White Wedding (Part 1).” The bass didn’t go much lower than before, but it was now more fleshed out, giving the music a richer, more solid base. Even the midrange seemed a bit smoother, perhaps because the amp was now relieved of the task of reproducing the deepest bass. With the Lyngdorf integrating the subs into my system’s sound, “White Wedding (Part 1)” sounded as clear and unrestrained as I’ve heard it in my room, the bass line and kick drum even more superbly delineated from each other, and Idol’s voice and Steve Stevens’s nasty guitar licks capturing the subversiveness of this punk icon’s signature song.


“Bad Guy,” from Billie Eilish’s When We All Fall Asleep, Where Do We Go? (16/44.1 FLAC, Darkroom/Qobuz), has some relatively deep bass recorded at a very high level that can overload many systems and rooms if played loudly enough. With the Lyngdorf, that bass was super articulate, and while obviously synthesized it sounded great, as if a big electronic drum kit sat between my speakers. Eilish’s voice was also placed at the exact center of the soundstage, with snapped fingers and other voices bouncing back and forth across the stage. The prolonged bass tones that begin 2:30 into the song sounded and felt as if they were emanating directly from the main speakers, though most of the lows were actually being reproduced by the subs. And no matter how high or low I set the volume, and regardless of the frequency, the integration of the output of subs and main speakers was absolutely seamless -- as good as the impeccable bass integration I achieve with my reference Anthem STR preamp’s ARC Genesis room correction.

Playing Sting’s My Songs on my Oppo UDP-205 and through the TDAI-3400’s optional analog input board via that board’s balanced inputs didn’t sound quite as good as through the digital USB input. The voices of Sting and Cheb Mami were still very clear, but the soundstage lost some of its cavernous depth, and the sound was a bit thin in comparison. This wasn’t surprising -- the Oppo has a pretty good DAC, but there’s no good reason to subject a digital file to an unnecessary additional D/A conversion when you can send it directly to the TDAI-3400, thus ensuring that it remains unaltered and in the digital domain until converted to analog at the speaker outputs. However, if you have a high-quality phono preamp, using the TDAI-3400’s optional analog board makes sense. And for those who wish to use the TDAI-3400 in a video system with a BD player or cable box, Lyngdorf provides the optional module of HDMI inputs, which many stereo components lack.

While many systems excel at reproducing the exaggerated imaging of multitrack studio recordings, the Lyngdorf could also reproduce the arrestingly natural-sounding Dolce Duetta, from mezzo-soprano Cecilia Bartoli and cellist Sol Gabetta (24/96 FLAC, Decca). The aria “Fortuna e speranza,” from the opera Nitocri, by Antonio Caldara (1670-1736), opens with an exquisite solo by Gabetta, her cello exhibiting a beautifully natural-sounding resonance and woody tone that’s then joined by the Capella Gabetta, the chamber ensemble led by her brother, violinist and conductor Andrés Gabetta. The images on this recording aren’t razor sharp, but each instrument was placed perfectly around Bartoli in intimate proximity -- she and the small ensemble sounded as if they were in my room. When I closed my eyes, the timbre of each instrument was exquisitely reproduced, as was Bartoli’s gorgeous voice, these Baroque arias effortlessly filling my room even with the unadorned dolce vocals or when a solo instrument was played pianissimo.


The Lyngdorf TDAI-3400 may lack my reference Anthem components’ absolute command in driving my MartinLogan hybrid electrostats to ultra-loud levels while controlling the deep bass, but it didn’t lag far behind -- and even that gap was considerably closed when I switched in the subwoofers. Both offered seamless integration of the sound of the subs’ output, the result being a truly full-range sound unattained in my room by any other combination of speakers and electronics and/or speakers and subs. Even with the subwoofers, the Anthems still had slight edges in dynamics and a fuller yet still agile and transparent bass response -- but I sometimes got a subtle and fleeting feeling that the Lyngdorf might be a touch sweeter and more musical through the midrange and highs.

Like the Anthem STR preamp, the Lyngdorf has a home-theater mode, but unlike the Anthem, it passes along only the left and right main channels (it has no inputs that allow the routing of the LFE channels to the subwoofer outputs). Although it is not clearly stated in the manual, I was informed by Lyngdorf Audio that bass management and RoomPerfect remain active in home-theater mode. That means that you could combine the LFE channel with the L/R main channels in the surround processor, and then have the TDAI-3400 extract and route the low frequencies with its bass management. Subwoofers would then be active during both stereo listening and when home-theater mode is activated. The Anthem has a fully featured and adjustable moving-magnet/moving-coil phono stage though it lacks a headphone output, the TDAI-3400’s wireless and streaming features, optional HDMI connectivity, and additional equalization (though the Anthem does permit some customization of the target curve). I was informed by Lyngdorf Audio that the optional analog input board now includes an MM phono stage in place of one of the RCA inputs.

The TDAI-3400’s headphone output was merely adequate, not up to the stellar standard of every other aspect of its performance. Through Sennheiser HD 580 or PSB M4U 8 headphones, it sounded as clean and clear as it did through my MartinLogan speakers -- but compared to the headphone output of the Oppo UDP-205, it lacked a bit of drive, and some weight in the bass.

Perfect knowledge

I think I enjoyed Lyngdorf Audio’s TDAI-3400 more than I have any other component I’ve reviewed. I enjoyed it so much that, when the time came to return the review sample to Lyngdorf the manufacturer, I didn’t want to. I love the sound of my Anthem components, and how they let me use the same system as a high-end home theater and for high-end music listening. But even including both optional modules, the TDAI-3400 offers much of the same quality of performance and breadth of features, especially for two-channel music, at a price ($7199) significantly lower than the Anthem combo’s $11,499.


There were more recordings I wanted to listen to, and others I wanted to hear again through the TDAI-3400, having enjoyed them so much the first time -- but, alas, the time came to return it to Lyngdorf Audio. There are only a few of the many products I’ve had in my system over the past two decades that I won’t soon forget. The Lyngdorf Audio TDAI-3400 is one of them.

. . . Roger Kanno

Associated Equipment

  • Speakers -- MartinLogan Masterpiece Classic ESL 9
  • Subwoofers -- JL Audio E-Sub e112 (2)
  • Preamplifier -- Anthem STR Preamplifier
  • Amplifier -- Anthem M1 (monos)
  • Sources -- Lenovo IdeaPad computer running Windows 10, foobar2000, Roon, Qobuz; AudioQuest JitterBug jitter reducer, Oppo Digital UDP-205 4K Ultra HD universal BD player
  • USB link -- AudioQuest Carbon
  • Speaker cables -- Analysis Plus Silver Apex, Clarus Aqua Mk.II
  • Interconnects -- Analysis Plus Silver Apex and Super Sub, Clarus Aqua Mk.II
  • Power cords -- Essential Sound Products MusicCord-Pro ES
  • Power conditioners -- Blue Circle Audio PLC Thingee FX-2 with X0e low-frequency filter module, Zero Surge 1MOD15WI

Lyngdorf Audio TDAI-3400 Integrated Amplifier-DAC
Price: $6499 USD ($7199 as reviewed).
Warranty: Two years parts and labor.

Lyngdorf Audio
Ulvevej 28
7800 Skive
Phone: +45 9614-5600