Japan’s Technical Audio Devices Laboratories, Inc. (TAD) has introduced the TAD-M2500TX, a two-channel power amplifier that joins its Evolution series of high-fidelity components. This new amplifier boasts a fully reengineered circuit design, enhanced transformers, and a newly crafted machined aluminum chassis. It delivers an impressive 550 watts of power per channel at a four-ohm load.
TAD TAD-M2500TX: ultimate symmetry in circuit and topology
Sources of positive and negative currents passing through the voice coils of a speaker driver must be identical in order to drive the diaphragm with the utmost precision. To achieve this, the TAD-M2500TX employs a bridge-tied load (BTL) design that connects two separate amplifiers in a balanced configuration for the left and right channels in the amplification circuit from the input to the output stages. In this design, positive and negative power supplies maintain perfect symmetry between them, and all power supply circuits are designed separately for each channel.
The redesigned, machined aluminum chassis has no joints and helps reduce the impedance of the ground point that serves as a reference point for symmetry. The self-proclaimed painstaking effort to achieve ultimate symmetry between left and right channels and between positive and negative signals did not stop there. TAD redesigned the ground point not only electrically but also structurally, and redesigned the circuit and its layout in the first amplification stage.
TAD TAD-M2500TX: High capacity, higher purity and efficiency transformers
The TAD-M2500TX is powered by improved dual toroidal transformers with a high power rating of 1kVA each. To increase the purity of the power supply, the internal coil of the transformer is directly connected to the power circuit, minimizing the contact points with the lead wires. In addition, the terminals for direct-connection coils, motherboard mounting terminals, and terminal screws are all made of oxygen-free copper coated with non-magnetic materials to eliminate even the slightest magnetic distortions.
The cross-sectional shape of the transformer core has been redesigned to circular in the TAD-M2500TX, from square in its predecessor. The circular design improves contact between the core and the coils, minimizing unwanted leakage of magnetic flux and vibration. The result is a power supply with greater purity and responsiveness, contributing to exceptionally accurate drive of speaker diaphragms.
TAD TAD-M2500TX: 550 Watts per channel power into four Ohms
We are used to specifying the power at a speaker impedance of eight ohms, but Japanese manufacturers in particular have a habit of specifying the power at four ohms because that is usually a higher number of watts. The superficial reader then thinks that the amplifier is much more powerful. According to TAD, the TAD-M2500TX delivers 550 watts of power per channel at four ohms. That will probably be around 300 watts at an eight ohm load, but it could also be a bit more (or less). This is made possible by the simplified class D single-output stage consisting of power MOSFETs with ultra-low resistance in the “on” position in lead-free packages that boast minimal power losses and high-speed responses. Combined with a machined aluminum chassis with excellent heat dissipation, the result is a powerful yet responsive and transparent dynamic sound reproduction.
TAD TAD-M2500TX: Precision design for vibration control
The TAD-M2500TX chassis is machined from a solid block of 90 kilograms of aluminum with extensive milling. This heavy, seamless design eliminates the adverse effects of external vibrations and helps stabilize the ground potential and music signals sent to the speakers. The TAD-M2500TX’s heavy cabinet is raised on three feet with internally inverted spikes, which physically isolate the chassis from external vibrations that may enter through the floor. Minimal contact with the surface on which the TAD-M2500TX is standing prevents external vibrations from traveling through the feet and adversely affecting circuits and components within the cabinet. This comprehensive vibration-control design results in a more condensed and energetic audio reproduction that preserves the spatial nuances of the music.
Rugged, oversized rear-panel speaker terminals, similar to those found in the Reference Series power amplifiers, reduce mechanical and electrical stress on connected speaker cables to improve their stability and provide the best possible electrical connection.
TAD TAD-M2500TX: bi-amping option
The TAD-M2500TX offers a bi-amping option for compatible speakers. With this option, one TAD-M2500TX can be connected to the tweeter terminals of the right and left speakers, and another to their woofer terminals. The bi-amping connection eliminates interference between the speaker drivers and improves their separation. This option brings out the best in amplifiers and speakers, allowing them to deliver sound with exceptional clarity.
TAD M2500TX: Technical Specifications
- Max. power per channel (4 Ohm, 1 kHz): 550 Watts
- Nominal distortion (275 Watts, 4 Ohms, 1 kHz): less than 0.05%
- S/N ratio: better than 112 dB
- Frequency response (+0 dB/-3 dB): 10 Hz to 50 kHz
- Gain factor: 29.5 dB
- Sensitivity/impedance XLR input: 1.5 Volt/100 kOhm
- Sensitivity/impedance cinch input: 0.75 Volt/50 kOhm
- Power consumption in operation: 250 Watt
- Standby power consumption: 0.5 Watt
- Dimensions (W x H x D): 440 x 170 x 467 millimeters
- Weight: 42 kilograms
