Интегральные усилители — Arcam Radia A25

The Radia A25 is the integrated amplifier at the top of the original Radia generation from Arcam, a HARMAN-owned British company. The series was unveiled at the Vinyl Factory in London on 3 October 2023 together with the A5 and A15 amplifiers, the CD5 disc player and the ST5 streamer, with shipping expected in the fourth quarter of 2023. The A25 carried a launch price of USD 1,499 and was later succeeded by the A25+.

Key specs that matter

The fifth generation Arcam Class G output stage delivers 100 W per channel continuously into 8 ohm at 0.5% distortion and 165 W per channel into 4 ohm at 1 kHz, staying in pure Class A for roughly the first 15 W. Harmonic distortion at 80% of rated power into 8 ohm at 1 kHz is 0.002%. The three RCA line inputs measure 106 dB signal to noise, A-weighted and referenced to 50 W with 1 V input, and respond from 20 Hz to 20 kHz within 0.2 dB. An onboard MM phono section is loaded at 47 kohm and 100 pF, with RIAA accuracy of 1 dB. Including feet the case is 431 x 344 x 83 mm, and it weighs 9 kg net or 12 kg packed.

Engineering and use context

Within the original Radia trio, the A25 was the only model with Class G amplification, an ESS ES9280A PRO converter and a USB-C input. USB-C accepts PCM up to 384 kHz and DSD64, DSD128 and DSD256, while the coaxial and optical sockets are limited to 192 kHz, at bit depths of 16, 24 and 32 bit and a digital signal to noise ratio of 110 dB. Bluetooth with Qualcomm aptX Adaptive carries 24 bit audio through an internal antenna, and the amplifier lists support for headphones over cable or over Bluetooth. The wired output provides 2.5 V RMS into 32 ohm and 5 V RMS into 300 ohm for loads from 16 ohm to 2 kohm. An integrated OLED display is set flush into the front, and over the Arcam Comms link cable it can show source information. The shell is solid aluminium in matte black with Radia yellow accents, and a rear connector cowl, styled after performance car diffusers, hides the cabling. The control knobs were redesigned with a curved, satin black textured finish. Maximum consumption is 500 W, standby stays under 0.5 W, and a remote with two AAA batteries is supplied.

Pairing

A computer feeds DSD and high rate PCM files over USB-C, while the ST5 streamer and CD5 player come from the same series and share its styling. An MM turntable needs no separate phono preamplifier.

Alternatives

The Arcam Radia A15 is the Class AB integrated amplifier one step below in the original Radia series.