Усилители мощности стерео — Chord ULTIMA 6

The ULTIMA 6 is a 180-watt stereo power amplifier from Chord Electronics and the most affordable entry point into the company's next-generation ULTIMA family of stereo power amplifiers. It builds on the SPM 1050 MK II and replaces that model's circuit with the new ULTIMA topology. Chord builds it by hand in Britain, covers it for five years and makes the aluminium body available in black or silver versions.

Key specs that matter

Each channel delivers 180 W RMS into 8 ohm and 350 W RMS per channel into 4 ohm. Chord quotes total harmonic distortion of 0.005%, a frequency response of 0.5 Hz to 100 kHz at the minus 1 dB points and a gain of 30 dB. The amplifier draws up to 1,500 W at full power and 10 W in standby. With the included Integra legs it stands 18 cm high, 48 cm wide and 36 cm deep. Fitted with the optional side blocks instead, it is 15 cm high and 42 cm wide at the same depth. Weight is 22.4 kg.

Engineering and use context

The dual-feed-forward circuit by John Franks took 30 years to develop and is Chord's first all-new amplifier topology in three decades. The output stage uses 16 proprietary TO3-style dual-die lateral MOSFETs, matched and watched continuously by error-correction circuitry at the output. Their drive circuitry reaches a slew rate of 300 volts per microsecond. The input section is fully balanced, with DC-tracking servos and full temperature compensation, while the output stage operates in sliding-bias Class AB, fed by an HF switch-mode supply. The casework is solid aircraft-grade aluminium, chosen to form a non-resonant enclosure, and the redesigned fascia is 28 mm thick. A recessed spherical polycarbonate power button glows in both standby and on states. Its brightness is set with a concealed switch hidden in the vertical gap that splits the front. The Integra legs come in argent silver or jet black, and the gloss black acrylic side blocks cannot be stacked.

Pairing

Around the back sit a gold-plated XLR input pair for balanced sources, a gold-plated RCA pair for single-ended ones and gold-plated speaker binding posts rated for high current. A 12 V trigger input handles Chord Auto Start, and power arrives through a C-19 IEC connector with a 15 A mains cable in the box. Chord lists the ULTIMA PRE 3 preamplifier, the DAVE DAC, the Hugo M Scaler and the Hugo TT 2 as matching partners.

Alternatives

For smaller systems Chord makes the BerTTi, a compact stereo power amplifier with the same dual-feed-forward topology.