Усилители мощности стерео — Rotel C8+

The Rotel C8+ is an eight-channel Class AB amplifier that the company files under custom installation, built to feed several listening zones from one 2U rack chassis. It combines analogue and digital inputs with a routing matrix, so each zone can be given its own source, level and tone settings, and it is sold in black only.

Key specs that matter

Rotel rates the C8+ at 100 W per channel into 8 ohm with all eight channels working, and 150 W per channel into 4 ohm. Pairs of channels can be bridged to deliver 300 W into a 4 ohm load. Rotel lists harmonic and intermodulation distortion at under 0.1% each, and the damping factor is 80 between 20 Hz and 20 kHz into 8 ohm. Through the analogue inputs the response runs from 10 Hz to 100 kHz within 0.5 dB, and noise sits 100 dB below full output, IHF A weighted. Through the digital inputs the bandwidth is 10 Hz to 20 kHz and the noise figure 102 dB. Channel separation exceeds 50 dB. The case measures 430 x 97 x 414 mm and weighs 18.35 kg.

Engineering and use context

The supply is based on a custom engineered toroidal transformer. There are four analogue inputs on RCA sockets, rated at 0.43 V sensitivity, 31 kOhm impedance and 2.8 V overload, plus four optical digital inputs that accept SPDIF LPCM up to 192 kHz and 24 bit. Four separate 24 bit and 192 kHz converters from Texas Instruments handle the digital streams. Any of the eight inputs can be sent to any zone. Bass and treble adjust by 10 dB either way at 100 Hz and 10 kHz. A 12 volt trigger input is fitted, and external control systems can operate the unit over IP or RS232. Rotel states that the 2U case needs no clearance above or below when mounted in a rack, and rack ears come in the box. Maximum draw from the mains is 980 W, standby consumption is under 0.5 W and network standby under 2 W, while the thermal load is given as 2744 BTU/h with the amplifier at 1/8 of rated power.

Pairing

The matrix of four digital and four analogue inputs lets a streamer, a TV optical feed and analogue sources share the same box, with the IP and RS232 ports tying it into a whole-house control system and the trigger input switching it on together with a preamplifier or receiver. Bridged operation suits zones where one pair of speakers needs more power than a single channel provides.

Alternatives

The Rotel C8 is the eight-channel sibling without digital inputs, rated at 50 W per channel into 8 ohm and 70 W into 4 ohm in the same size case.