Предусилители — Electrocompaniet EC 4.8 MKII

The EC 4.8 MKII is a two-channel reference preamplifier from Electrocompaniet, manufactured in Norway. Its analogue audio circuitry is fully balanced and discrete, with direct coupling throughout the signal chain.

Key specs that matter

Rear panel inputs comprise two balanced XLR pairs, labelled AN1 and AN2, and three single-ended RCA pairs, AN3 to AN5, the last of which doubles as the home theatre input. The variable-level main output uses XLR and an RCA record output at fixed level. Input impedance is 47 kohm and output impedance is 100 ohm. Maximum input level is 15 V peak-to-peak on single-ended connections and 30 V peak-to-peak balanced, while the output can swing up to 30 V peak-to-peak. Gain ranges from -111 dB at its lowest setting to 6 dB at maximum. The noise floor at 0 dB gain is below -130 dB, frequency response extends from 1 Hz to 200 kHz, channel separation exceeds 120 dB, and THD stays under 0.002 percent measured with 1 V in and 1 V out. The case is 470 mm wide, 372 mm deep and 80 mm high, weighs 11.3 kg and draws 30 W with no load or signal.

Engineering and use context

Each channel of this dual-mono layout draws on its own independent power supply, and the circuits run in pure Class A with heavy storage capacitance. Volume is set by a proprietary electronic control that Electrocompaniet states took a decade to develop, with about 1000 steps at close to 0.1 dB resolution. In home theatre pass-through mode the HT input is switched automatically to unity gain. The record output sits outside the volume control. On the front panel a power switch is joined by four buttons for volume up and down and for stepping through sources, while a display indicates the selected input. Holding mute for one to two seconds switches to standby. The handset included in the box, powered by two AAA cells, uses the RC5 code protocol and has dedicated input selection and volume buttons. SPAC A and B connectors on the back communicate with compatible Electrocompaniet power amplifiers such as the AW 2x120 and AW 3x120, and a USB port serves firmware updates.

Pairing

With a balanced-only main output, a power amplifier fitted with XLR sockets is required, for example Electrocompaniet's AW 800 M monoblock, whose voltage gain is specified for its balanced input.

Alternatives

Electrocompaniet's EC 5 is a stereo reference preamplifier offering 4 XLR and 2 RCA stereo inputs, also run in pure Class A with independent supplies per channel.