Tact Audio Millennium mkIII Digital Amplifier

I am the original owner and bought it as a Mk II.   Around 2005 I had it upgraded to the Mk III circuitry done at the Lyngdorf factory in Denmark.  It is perfect condition with zero blemishes and in a smoke free environment.  It has just returned from the factory after being checked out with a clean bill of health.  I have always fed it with a digital signal from a TacT RCS 2.0s.  It does have balanced analog inputs as well with 4 digital inputs.  All selectable from the front.

Background

TacT was Lyngdorf's US based brand which rebranded the Lyngdorf Millennium amplifier but was built with the same design in their Denmark production facility.  TacT also designed and manufactured a line of room correction pre-amps which were only built under the TacT name in the US.  It later became the now current Lyngdorf "Room Perfect" room correction system.  TacT no longer operates but all service on the Millennium amps are performed by Lyngdorf as it always did in the past.

The Millennium Mk III is the TacT/Lyngdorf reference amplifier - its speed, precision and incredible dynamic range has taken the world by storm. Not to mention the unique volume control working with the precision of Swiss clockwork.

If you are looking for unconstrained sound, speed and the ultimate sense of freedom this is it! 
The incredible dynamic range of the Millennium Mk III amplifier creates a musical experience where the completely "black" silence enhances the finest musical details.

The Millennium Mk III is much more than an amplifier - some call it a "Power DAC" - but in fact it is a complete digital control center replacing a D/A converter, pre-amplifier and power amplifier.

Despite that this is probably the most technologically advanced products of its kind  - simplicity is the keyword for its design. Dominated by the massive aluminium front plate and the eye catching and "cool" volume wheel. If you have once spun it, you will never want to use anything else.

True Digital Amplifier

In principle, the output stage of most switching amplifiers has the same working principle. PWM = Pulse Width Modulation is simply a matter of variable open/close time of the transistors. Simplified, you can compare the transistors in the output stage to two switches.

Power Supply and Volume control

The TacT/Lyngdorf true digital amplifiers are based on non-feedback construction, which means there are no differences in the THD performance at any frequency when it comes to the output stage. In other words, the distortion is very low and linear. However, another major influential factor to the THD performance of a fully digital amplifier is the quality of the power supply.

With the TacT/Lyngdorf power supplies that were obtained have completely identical and very low impedance which gives a completely flat THD at all frequencies. This is simply a necessity for a high performance implementation of a true digital amplifier.

The power supply uses a toroidal transformer and the advantage of this over a conventional C or El core transformer is significantly less magnetic radiation, something which can potentially induce noise (50/60Hz) which would be very audible.The supplies for the output stage and the microprocessors are kept completely separate since they use separate windings on the transformer.

However, the truly unique aspect of the power supplies in the TacT/Lyngdorf true digital amplifiers is that it actually works as the volume control of the product. When you are playing at low volume levels, the voltage supplied to the output stage is low - when you turn up the volume control you increase the voltage, and thereby the output, from the amplifier. This is implemented as a DC-DC converter. On the "primary" side full voltage is constantly applied and then the DC-DC converter switches the voltage needed for a given setting of the volume control to the "secondary" side (= the voltage supplied to the output stage).

In order to be able to turn down the volume fast again, the DC-DC converter can, quite uniquely, switch the power back to the "primary" side. The result of this truly unique way of controlling the volume level is that a TacT/Lyngdorf true digital amplifier gives full dynamic range from maximum volume and down to the 62dB reading in the volume control (which corresponds to as little as 1V RMS on the speaker terminals). This is due to the fact that when the supply voltage to the output stage is reduced, then you lower both the output signal AND the noise floor; and thus the full dynamic range is maintained - also at low volume levels. Perhaps this is one of the reasons why reviewers often mention that TacT/Lyngdorf amplifiers play equally well whether you're playing at high or low volume levels.

Specs 

Output power, 4 ohms2 x 300 Watt  1KHz, 0.1% THD+N Output power, 8 ohms2 x 150 Watt1KHz, 0.1% THD+N Nominal load impedance     4 - 8 Ohms It is safe to operate the amplifier with no load Frequency response0.3Hz-33KHz-3dB points, 8ohms load. Frequency response20Hz-20KHz-0dB/+0.2dB  8ohms load Output impedance 0.020 Ohms 20Hz-1KHz Output impedance 0.220KHz THD+N0.01%@1W/8 ohms    A-wgt. THD+N0.015%@1 W/4 ohms A-wgt. THD+N0.06%@100 W/8 ohms A-wgt. THD+N0.02%@300 W/4 ohms A-wgt. S/N ratio113dBA-wgt. Ref. 200 /8 ohms Dynamic range140dBA-wgt. Ref. 200 W/8 ohms Channel separation100 dB1 KHz, 200 W/8 ohms Peak output current+/-50A  Mains voltage range
115 version110-120 VAC, 50-60Hz Mains voltage range
230 version200-240 VAC, 50-60HZ Power consumption
Standby mode 3 W Power consumption
On mode, no output 30 W  Power consumption
2 x 37.5 W / 4 Ohms 110 W Power consumption
2 x 300 W / 4 Ohms 800 W  Width 450 mm   Depth 445 mm Incl. loudspeaker connectors  Height 145 mm Incl. feet Net weight 25.4 kg   Shipping wight 30.0 kg

What is included:

All original manuals

Factory Remote

RS232 interface cable for tuning the subwoofer out crossover and basic setup (never need to touch any of it)

IEC Power Cord

Misc review

The TacT/Langdrof Millennium MK I, was released in 1998 as the first “truly” digital amplifier. In its third generation, this single chassis "power DAC" is packed with capabilities offered by no other pre-amplifer/amplifier/DAC. These capabilities include built-in digital audio signal processors for equalizers, crossovers, and time-delay adjustment, an improved clock system that provides a 6dB improvement in signal to noise and jitter reduction, a digital transceiver supporting 192kHz/24bits, a new asynchronous sample rate converter, and a DA converter with balanced output to allow the connection of subwoofers. In comparison to the Millennium MK II, the MK III is much more relaxed, dynamic, and has better front-to-back soundstage, layering, space between instruments, focus and bass solidity. Established as the baseline for realism, intimacy and transparency, the MK III upgrade removes another veil to better communicate the emotion in the music. 

Offers will be considered.