Lyngdorf TDAI-2170: An extremely versatile device

The power amplifier develops a power of 2 x 170 W at 4 Ohms with distortion of 0.07%, while the entire device weighs only 8 kg. You must agree that such mass-energy indicators are unrealistic for traditional AB amplifiers. Low distortions are due to the fact that the PWM clock frequency is increased to 400 kHz – today this is a record figure for pulse power amplifiers. In addition, as the manufacturer indicates, there are no sources of internal noise in the TDAI-2170 path, which causes dead silence during pauses. This property is called “Blackground”. And, as I already mentioned, all the listed parameters are obtained without general feedback.

Speaking about the audio path, in a very simplified form it can be described as follows: the input PCM format is directly modulated into a PWM (pulse-width modulation) signal, which controls powerful output MOSFET keys. In this case, the analog signal is formed directly at the output acoustic terminals.

In fact, the path is a little more complicated – it has a DSP, which implements several proprietary Lyngdorf solutions. The most interesting thing is the Room Perfect room correction system, which has a number of important differences from the widespread Audessy, Dirac, MCACC, etc. Firstly, it has two settings modes – Focus1 and Focus2. In the first case, the sound field is optimized for one listener, and in the second – for a small audience. Moreover, Room Perfect not only aligns the frequency response, eliminating the effects of standing waves, but also minimizes phase interference. The latter circumstance affects the formation of the sound scene, which is why two focusing modes have been introduced. If desired, Room Perfect can be disabled by setting the Bypass mode. The second important point is that to increase the accuracy of measurements, the microphone can (and should) be placed in several places in the room being studied. And if the full information about the acoustic features of the room is taken as 100%, then when measuring from four points it will be 95%, and from seven points – 99%.

Another unique technology of the Danish company, Intersample Clipping Correction (ICC), is able to restore the original waveform at its peaks if the audio file fed to the input was recorded with a level of 0 dBFS or exceeding it. By the way, this is a real problem, since many modern high-res are created according to the principle of “the louder, the better.” In fact, such a level is not acceptable for all DACs – even if the level reaches -0.5 dBFS at the peaks, noticeable distortions may appear during upsampling. So, the ICC algorithm detects such fragments and eliminates clipping by slightly reducing the overall volume level, but at the same time the full dynamic range of the original recording is restored.

Thanks to the modular design, the amplifier can be configured optimally for each specific system. The modules installed in the amplifier are activated according to the Plug-n-Play principle thanks to advanced software. Perhaps the most important addition is a USB converter with an asynchronous “B” input, capable of receiving PCM with a resolution of up to 32 bits/384 kHz, as well as audio in DSD64 and DSD128 streams. All this is reproduced without intermediate conversion to analog form, as is the case in conventional class D amplifiers.

The second module is perhaps the most unusual for a stereo device. It contains four HDMI 1.4 inputs and the same output, thanks to which the amplifier turns into a real control center for a multimedia system. The most interesting thing is that these interfaces are not implemented on standard chipsets and are intended, among other things, for high-quality transmission of digital audio. With such a configuration, an AV receiver will no longer be needed unless you intend to build a multi-channel configuration. In addition, a modern TV with Smart TV support is already becoming a network source of high-resolution content, and adding HDMI is a completely reasonable solution. And finally, the third module is designed for audiophile connections via analog inputs. It contains one balanced (XLR) stereo input and three regular RCA.

The basic version provides a pair of linear RCA inputs, a pair of coaxial and four optical Toslink. The rear panel also contains 12-volt trigger jacks, an RS-232 port, a USB A interface for firmware updates and four screw speaker terminals.

Lyngdorf components have always been distinguished by a distinctly futuristic style, and the TDAI-2170 is no exception. Thanks to the designers’ efforts, the amplifier visually seems smaller than it actually is. The avant-garde style of the front panel corresponds to the ideas about the aesthetics of a modern digital device: on the mirror plane there are only two three-dimensional objects – a small knob responsible for selecting an input/navigating the menu and the dominant volume control. This is a digital encoder with a very small step – you need to make several turns to change the level by one decibel. The dot display on the left shows service information in several lines and the set volume value in very large. The amplifier is controlled by a narrow stylish remote control.

Lyngdorf TDAI-2170 Specifications

Power — 2x 170 W at 4 Ohm
Inputs — 2x analog unbalanced, 2x coaxial, 3x optical
Outputs — coaxial, analog unbalanced
Dimensions — 100x450x360 mm
Weight — 8 kg

Optional modules:

HDMI switch — 4x inputs, 1x output; support for PCM up to 24bit/192kHz, DSD64, DSD128; auxiliary protocols CEC and ARC
USB module — support for PCM up to 32bit/384kHz, DXD, DSD64 and DSD128
Analog input block — 3x unbalanced inputs, 1x balanced; ADC Asahi Kasei AK5394A