Integrated amplifiers — Cambrige Audio CXA81

The Cambridge Audio CXA81 is a Class AB stereo integrated from the London-based company's CX series that also carries its own digital converter. It was sold at USD 1,299 in a Lunar Grey finish with a two-year warranty. It tops the CX amplifier pair above the smaller CXA61.

Key specs that matter

Rated output is 80 W RMS per channel into 8 ohm and 120 W RMS into 4 ohm. The analogue section offers four inputs, one of which switches between balanced XLR and RCA, while the other three are RCA only. Digital inputs comprise one coaxial S/PDIF, two TOSLINK optical, one USB audio and integrated Bluetooth 4.2 with aptX HD at 24 bit and 48 kHz. USB accepts PCM up to 384 kHz and DSD256 or DoP256, coaxial runs to 192 kHz and optical to 96 kHz. Frequency response is stated as below 5 Hz to 60 kHz within plus or minus 1 dB, and the damping factor exceeds 110 at 1 kHz. The unit measures 430 x 115 x 341 mm and weighs 8.7 kg, with a maximum consumption of 750 W and under 0.5 W in standby.

Engineering and use context

An ES9016K2M chip from the ESS Sabre family performs the D/A conversion. The toroidal mains transformer is wound with an individual secondary for every channel, and each side also gets its own rectifier block and filter capacitors, so the left and right power stages draw from independent supplies. Two sets of speaker posts are selected as A or B from the front panel. Line-level connections include a variable RCA preamp output and an RCA subwoofer output with a 2.5 kHz crossover at 12 dB per octave. A dedicated headphone amplifier drives a 3.5 mm jack on the front. For integration into automated systems there is an RS-232 port and a 12 V trigger input and output, and the amplifier is Roon tested. Nine front buttons, a large volume knob and a display handle operation on the unit, and a full-size remote control is supplied.

Pairing

With one analogue input switchable to XLR, a CD player or network streamer with balanced outputs can be connected directly, while computers and phones use the USB and Bluetooth paths without a separate DAC. The preamp output leaves room to bring in a stronger power amplifier later, and the dedicated subwoofer output feeds an active sub for compact stand-mount speakers in a 20 m2 room.

Alternatives

The Cambridge Audio CXA61 is the lower-powered CX series integrated at 60 W into 8 ohm and 90 W into 4 ohm, with an ESS Sabre ES9010K2M DAC, four RCA inputs plus a front 3.5 mm input for portable players, and no balanced connection.