Усилители мощности стерео — TAD TAD-M700

The TAD-M700 is a monaural amplifier from the Japanese company Technical Audio Devices Laboratories, usually shortened to TAD. The model is part of the Reference series and was developed alongside the TAD-M700S, a two-channel version built in the same enclosure. Because each chassis carries a single amplifier channel, a stereo setup calls for two units, and TAD rates both models with the same published bandwidth, gain and noise figures. The design goal stated by TAD is end-to-end symmetry, bringing its proprietary circuit technologies together within one unified design.

Key specs that matter

Rated output is 350 W into 8 ohms and 700 W into 4 ohms, both measured at 1 kHz. Rated distortion stays below 0.005 percent at 1 kHz with 350 W into a 4 ohm load. The signal-to-noise ratio is 125 dB or higher, IHF A-weighted. Frequency response runs from 1 Hz to 100 kHz, plus 0 and minus 3 dB. Gain is 29.5 dB, and the input needs 1.5 V to reach full output, presented with an impedance of 100 kilohms. The amplifier draws 590 W while operating and 0.5 W or less in standby, and European units take 220 to 230 V mains at 50 or 60 Hz. The chassis measures 516 mm wide, 296 mm high and 622 mm deep, and the unit weighs 74.5 kg.

Engineering and use context

For its output section the M700 uses a completely symmetrical BTL, meaning bridged transformerless, configuration, and TAD describes the amplifier as operating in Class A/B. The input stage relies on matched pairs of FET devices, which lets the circuit amplify with a minimal number of components. A DC servo circuit keeps the amplification stable against changes in operating temperature and in the magnitude of the input signal. The power supply is built around twin transformers with hand-wound coils, rated at 2.8 kVA in total, and four custom capacitors of 33,000 uF each store energy for the output stage. The enclosure is a cast-aluminium monocoque chosen for its high internal loss factor, which TAD says eliminates sympathetic vibration at unwanted frequencies. A wide stance and slanted side angles lower the centre of gravity, and four height-adjustable spike feet support the unit.

Pairing

Within the TAD range the TAD-C1000 preamplifier from the Evolution series provides balanced XLR outputs that match the balanced input philosophy of this power amplifier.

Alternatives

The TAD-M700S uses the same cast-aluminium chassis with two channels at 175 W each into 8 ohms, for owners who want stereo from a single enclosure.