Интегральные усилители — Musical Fidelity M8XI

The M8xi is a Musical Fidelity super integrated amplifier built as a separate preamplifier and two monobloc power amplifiers inside a single chassis. Each channel has its own heat sink and its own transformer, making it a dual mono design, and the preamplifier section gets a dedicated power supply mounted close to the input sockets to keep circuit board tracks short. A five-input DAC based on the Texas Instruments PCM5242 chip, with its own supply, is built in. List prices were USD 6,499, GBP 5,649 and EUR 6,999.

Key specs that matter

Output is 550 W per channel into 8 ohms and 870 W into 4 ohms from 20 Hz to 20 kHz, with 1.6 kW peaks into 2 ohms. Maximum output voltage is 67 V RMS, clipping starts at 190 V peak to peak, and the maximum peak current is 105 A. THD plus noise is below 0.004 percent typical via XLR, signal to noise exceeds 86 dB A-weighted, and response runs from 10 Hz to 100 kHz within plus 0 and minus 1 dB. Damping factor is 150. The case measures 485 x 185 x 510 mm, weighs 46 kg, and maximum consumption is 2000 W.

Engineering and use context

Each channel carries twelve large bipolar transistors capable of 200 A peak to peak, arranged as three plus three bridged output pairs. Large cooling plates run along both sides, and the black aluminium front plate is 1.5 cm thick. Two large knobs select the input and set the volume, a display shows the chosen source, and a home theatre input bypasses the volume control. The amplifier lacks a phono input as well as any wireless or network connection. A Class A driver stage is used to improve efficiency while keeping a low feedback configuration. Analogue inputs are four RCA pairs with 25 kohm impedance and two XLR pairs at 50 kohm. The DAC accepts two coaxial S/PDIF inputs at up to 24-bit and 192 kHz, two optical inputs at 24-bit and 96 kHz and a USB Type B asynchronous input at 24-bit and 192 kHz. Digital outputs include one coaxial socket at 24-bit and 192 kHz and one optical socket at 24-bit and 96 kHz, and analogue outputs comprise a fixed RCA pair, a variable RCA pre-out and a variable XLR pair.

Pairing

The variable RCA and XLR outputs allow a subwoofer or additional power amplifier to follow the volume setting, and a recorder or external converter can be fed from the two digital outputs. The 2 ohm peak figure shows the output stage is intended for loudspeakers of low impedance, and the high consumption rating calls for a mains supply able to deliver it.

Alternatives

The Musical Fidelity Nu-Vista 800.2 is a Musical Fidelity integrated amplifier from a different series, combining a nuvistor tube stage with a dual mono output section.