Усилители мощности стерео — Chord BERTTI

The BerTTi is a compact, fully balanced stereo power amplifier from Chord Electronics, designed and handmade in the UK. Chord positions it as the most affordable stereo power amplifier in its portfolio built on ULTIMA technology, the dual-feed-forward topology that also runs through the larger ULTIMA models. It arrived in January 2024 as the successor to the TToby, priced at GBP 3,995, USD 5,250 or EUR 4,995, and it is offered in Jet Black or Argent Silver with a 3-year warranty.

Key specs that matter

Chord lists a frequency range of 5 Hz to 100 kHz within plus or minus 0.5 dB, total harmonic distortion of 0.008% and an A-weighted noise figure of 87 dB. Gain is 30 dB, input sensitivity is 0.78 V, and input impedance is 100 kOhm for either input type. At full power the amplifier draws 240 W from the mains, falling to 1 W in standby. The chassis measures 59 mm high, 235 mm wide and 256 mm deep, with a weight of 3.75 kg.

Engineering and use context

Chord credits the dual-feed-forward topology to John Franks and describes it as its first all-new amplifier circuit in three decades. The circuit uses error-correction technology that checks the signal continuously and removes errors ahead of the output devices. Power comes from a switch-mode design, and Chord fitted the BerTTi with two modified supplies to lift performance, plus an additional auxiliary rail for the front end. That rail supplies extra voltage to drive the custom-made MOSFETs in the output section. Connections at the rear are kept simple, with one stereo pair of balanced XLR inputs, one stereo pair of gold-plated unbalanced RCA inputs and a single pair of gold-plated speaker terminals. A 12 V trigger socket and a ground socket sit alongside them, and mains power enters through a 10 A IEC inlet. Its body is sized like the Hugo TT 2 and Hugo M Scaler.

Pairing

Chord names the Hugo TT 2 DAC and preamplifier as the partner for the BerTTi, so a two-box system can run from a digital source straight into this amplifier with volume handled by the Hugo TT 2. Chord also names the Hugo M Scaler upscaler, which can raise incoming audio to 705.6 kHz before it reaches the DAC. Because the BerTTi offers both XLR and RCA inputs, it can also follow any line-level preamplifier with either output type.

Alternatives

Within the ULTIMA family Chord also builds the ULTIMA 6 stereo power amplifier, rated at 180 W RMS per channel into 8 ohm.