Integrated amplifiers — Arcam SA45

The SA45 is the larger of the two streaming integrated amplifiers in the Arcam Radia series and was designed in Cambridge, England. Arcam describes it as derived from the A49, and it keeps both the digital and the analogue signal paths fully balanced. When it was announced for a 2024 release alongside the SA35 and the ST25 streamer, the US price was set at USD 4,999, and current pricing stands at GBP 4,499 and USD 5,500.

Key specs that matter

Continuous output with both channels driven is 180 W per channel into 8 ohm from 20 Hz to 20 kHz and 300 W into 4 ohm at 1 kHz, each at 0.5% THD. Harmonic distortion measured at 80% power into 8 ohm and 1 kHz is 0.002%. With a 1 V input and a 50 W reference, the analogue inputs give 106 dB A-weighted signal to noise, and digital sources at 0 dBFS give 110 dB. Response is flat within 0.2 dB between 20 Hz and 20 kHz. Width is 432 mm, depth 390 mm counting the speaker terminals and height 140 mm counting the feet. Net weight is 17 kg and the packed weight 20 kg.

Engineering and use context

Power comes from Arcam's fifth generation Class G circuit, which runs from a low voltage rail in normal use and switches to a higher voltage rail only for transient peaks. Arcam built a new six layer streaming board whose ground plane runs through the whole board, fitted ESS Hyperstream IV converters in a balanced layout with jitter elimination, and supplied everything from a linear toroidal transformer. The streaming section decodes FLAC, WAV, AAC, ALAC, AIFF, MP3, OGG, WMA and DSD up to DSD256 at 16, 24 or 32 bit and up to 384 kHz, and music on USB mass storage drives plays via a USB-A port. Supported protocols are AirPlay, Google Cast, Roon, Spotify Connect and Tidal Connect, with Roon Ready status promised after launch. A bonded 8.8 inch display shows cover art and metadata. Mains draw peaks at 1000 W, network standby uses under 2 W and full standby under 0.5 W.

Pairing

For analogue sources there are three RCA pairs, one XLR pair and phono inputs for MM and MC cartridges, while HDMI eARC/ARC, two coaxial and two optical sockets handle digital gear at 16 or 24 bit up to 192 kHz. Bluetooth 5.4 works as both receiver and transmitter, with AAC, Snapdragon Sound, LE Audio and Auracast, and Wi-Fi runs on 802.11ax. Dual subwoofer outputs allow two subs to be connected, and the higher rating into 4 ohm suits low-impedance speakers.

Alternatives

The Arcam SA35 is the smaller Radia streaming integrated, with 120 W per channel into 8 ohm and a 6.5 inch screen.