TADL Introduces the M700 and M700S Power Amplifiers as the Newest Addition to its Reference Series of Hi-Fi Audio Components in Its Relentless Pursuit of Excellence in Sound Quality

Model Description Available
TAD-M700 Monaural power amplifier December 2019
TAD-M700S Two-channel power amplifier December 2019

Technical Audio Devices Laboratories, Inc. (TADL) today announced the TAD-M700 and TAD-M700S power amplifiers as the newest addition to its top-of-the-line Reference Series of hi-fi audio components. The M700 monaural power amplifier replaces the highly acclaimed TAD-M600, with significantly upgraded design, construction, and components down to the smallest details inside and out. To provide greater versatility, we have added to the lineup the M700S two-channel bi-amp-capable power amplifier.

Main Features

1) Fully Symmetrical Design

The M700 and M700S have BTL (bridged transformerless) configuration that applies balanced connection between two separate but symmetrical amplifiers from input through to output in the amplification stage. This configuration, combined with symmetrical positive and negative power supplies and independently designed power circuits, enables the M700 and M700S to provide identical positive and negative electric currents to the voice coil of a speaker unit and deliver the accurate driving of a diaphragm. Furthermore, the M700 and M700S boast dual monaural construction with a fully symmetrical design for the left and right channels, right down to the circuit topology, PC boards, and wiring.

2) Elaborate Vibration-Suppressing Technology

The M700 and M700S employ a newly designed cast-aluminum chassis that boasts a high internal loss factor for vibration, eliminating inherent sympathetic vibration at unwanted frequencies. Components are laid out optimally inside the chassis to stubbornly resist vibrations induced by sound pressure from a speaker system. In addition, the low-impedance aluminum chassis demonstrates high electric stability.

3) Redesigned Adjustable Spike Feet

The M700 and M700S are supported by four redesigned height-adjustable spike feet, each having a single point of contact with the surface on which it stands. This ingenious design keeps vibration transmitted through the floor from affecting the components inside the case and keeps delicate audio signals from being masked by vibration-induced distortion. The result is more condensed and energetic audio reproduction and yet with spatial nuance of the music retained intact.

4) Redesigned Wide-Stance Chassis

The cast-aluminum chassis more gently curved than the predecessor provides a solid base that suppresses resonance vibration in the audible frequency range. The wide-stance chassis construction, inherited from the TAD-M600 power amplifier, was upgraded to lower the already low center of gravity of the whole unit by optimizing the slant angle of four feet at the corners.

5) Power Amplification That Enables the Powerful Driving of Speakers

The balanced-connected power amplification circuits of the M700 and M700S use high-power multiple-emitter transistors with superior high-frequency performance to provide the stable driving of speakers over wide frequency ranges. In addition, a non-magnetic resistor made of newly developed hybrid resistor elements is used for emitter resistance in the final output stage. All these components of higher reliability employed from the input through to output stages combine to deliver the powerful driving of speakers

6) Extra-Large-Capacity Power Supplies

Our years of expertise in achieving audio quality and reliability has culminated in twin gigantic power transformers with the total ratings of 2.8 kVA. In the production line of the M700 and M700S our certified artisans manually wind insulating sheets around the core of the transformer, eliminating the need for a bobbin so as to increase the binding between the primary and secondary coils. The coil is directly connected to the first stage of amplification to increase the purity of power supply and achieve more responsive and consistent audio reproduction. In addition, four custom-built 33,000㎌capacitors help effortlessly deliver dynamic and lively sound with excellent transient response for which the M700 and M700S were designed.

7) Simplified Voltage Amplification Stage

True to TAD’s long-held design philosophy of "Simple is best," the M700 and M700S employ an input circuit composed of a matched pair of FET devices to reduce the number of components required to make the circuit down to an absolute minimum, allowing music signals to be amplified in their purest form and go through the circuit without losing even the subtlest information. The new DC servo circuit enables stable amplification, resistant to changes in operating voltage, temperature, and magnitude of input signals. In addition, pairs of FET devices carefully hand-picked by our certified artisans in the production line were incorporated into the amplifier’s input circuit and DC servo circuit, which improves the operational stability of amplification. Moreover, we have taken our attention to detail a step further: we used non-magnetic carbon resistors for feedback resistors to eliminate the effect of magnetic distortion on the signal path.

8) Monaural Power Amplifier and Two-Channel Power Amplifier to Choose from

To provide greater versatility in building a truly high-end audio system, we have added to the lineup the M700S two-channel bi-amp-capable power amplifier. Two units of the M700S, both with the bi-amp mode switched on, in a system can power each speaker unit independently, improving the separation between channels and achieving a more accurate reproduction of sound field and sound image location. The M700 monaural power amplifier and the M700S two-channel power amplifier provide customers with a wider choice to choose from.

Main specifications

TAD-M700 TAD-M700S
Power output 700 W @1 kHz, 4 Ω
350 W @1 kHz, 8 Ω
350 W/ch @1 kHz, 4 Ω
175 W/ch @1 kHz, 8 Ω
Rated distortion 0.005% or less @1 kHz, 4 Ω, 350 W 0.005% or less @1 kHz, 4 Ω, 175 W
S/N ratio 125 dB or less
Frequency response 1 Hz to 100 kHz, +0 dB to -3 dB
Gain 29.5 dB
Input terminal (sensitivity) 1.5 V/100 kΩ
Power AC 100 V, 50 Hz/60 Hz
Power consumption 590 W
Standby power consumption 0.5 W or less
Dimensions W 516 × H 296 × D 622 mm
Weight 74.5 kg 75.5 kg