Integrated amplifiers — Cambrige Audio EXA100

The EXA100 is the integrated amplifier of Cambridge Audio's EX Series, which the London company presents as the successor to its Azur 851 range. Developed over three years at the company's London headquarters and music venue, Melomania, it uses amplifier modules based on the Edge M monoblock, with the same power transistors, and sits between the CX Series and the Edge line.

Key specs that matter

Output is 100 W RMS per channel into 8 ohms and 155 W into 4 ohms in Class AB, at below 1% THD+N. Frequency response runs from below 3 Hz to above 40 kHz within 1 dB. Inputs are four RCA line pairs and one balanced XLR pair, two optical and one coaxial S/PDIF, asynchronous USB-B switchable between USB Audio Class 1 and 2, HDMI eARC and Bluetooth 5.0 with aptX HD. Conversion uses an ESS ES9018K2M DAC, and in USB Audio Class 2 mode the input accepts up to 24-bit/384 kHz and DSD256. THD is below 0.002% at 1 kHz at rated power, damping factor exceeds 160, and S/N measured against 1 W into 8 ohms is over 91 dB. Outputs include a headphone socket, an RCA pre-out, two sets of speaker outputs and bi-wiring capability. The chassis measures 430 x 115 x 341 mm and weighs 12.8 kg.

Engineering and use context

The power supply is based on a heavily shielded toroidal transformer, a component Cambridge Audio first used in its P40 amplifier of 1968. It is flanked by heavy-duty heatsinks visible through the top grilles. The circuit is laid out on four-layer circuit boards. Protection follows the proprietary CAP system, which uses four separate detection methods to guard against faults, and grounding was designed across the whole unit. A Power Amp Mode bypasses the volume control so the EXA100 can work purely as the power stage for a separate preamplifier or AV processor. The HDMI eARC input brings television sound into the system with volume control from the TV remote. The milled aluminium front panel carries a knurled volume knob, and the aluminium remote matches the EX Series styling. Two speaker zones can run in different rooms, selectable from the front panel.

Pairing

The EXA100 drives most floorstanders and stand-mounts in rooms up to about 35 m2. The balanced input is designed for the EXN100 network streamer, and the pre-out feeds an active subwoofer. Vinyl requires an outboard phono stage, such as Cambridge Audio's Alva Duo, or a wireless Alva TT V2 through the Bluetooth input.

Alternatives

Cambridge Audio's CXA81 is the smaller 80 W integrated amplifier with a built-in DAC in the CX Series.