Усилители мощности моно — Musical Fidelity NU-VISTA PAM

The Nu-Vista PAM is a monoblock power amplifier in the Nu-Vista series of Musical Fidelity, introduced in 2023 alongside the Nu-Vista PRE preamplifier and PAS stereo power amplifier. It expands on the PAS design, and the added space inside allows a modified internal layout. Each PAM comes with its own outboard power supply and costs EUR 22,000 or USD 23,930.50 per unit, while the UK recommended price was GBP 20,499 before the model was listed as no longer available. Musical Fidelity describes the circuit as a balanced configuration with a balanced input, high power, low distortion bridged output stage, and each PAM handles only one channel.

Key specs that matter

Output is 600 W into 8 ohm, 1,000 W into 4 ohm and 1,500 W peak into 2 ohm. The amplifier delivers 69 V RMS and 150 A peak to peak, and damping factor is 180. Gain is 16x, or 23.5 dB. Typical THD plus noise stays under 0.003% from 20 Hz to 20 kHz, A-weighted noise is more than 108 dB down and response is +0 and -1 dB from 5 Hz to 50 kHz. Input impedance is 100 kohm. Maximum power consumption is 2,150 W. The amplifier chassis measures 483 x 187.5 x 475 mm and weighs 27 kg, and the power supply unit shares the 483 mm width and 187.5 mm height and adds 40 kg.

Engineering and use context

Musical Fidelity bases the output section on the Titan 1000 W stage, with separate capacitors and chokes, and its Class AB biasing gives more than 5 W of initial Class A operation. The input is buffered by four 6S51N nuvistor valves in a discrete Class A stage, while the output section uses 2 x 5 pairs of high power thermally compensated output devices. The PAS stereo model shares the Nu-Vista platform, while the PAM devotes all of its output devices to a single channel. Keeping the mains supply in a separate box removes mains noise from the audio circuitry. Panels are milled aluminium and serve as electromagnetic shielding. Discrete inputs comprise two RCA and two XLR connectors, with one RCA and one XLR loop through output.

Pairing

Two pairs of 4 mm banana plug binding posts are fitted for the speaker cables. The loop through outputs send the input on to another power amplifier. Trigger input and output use 3.5 mm mono jack sockets, so power-up can be linked with other components. The matching preamplifier is the Nu-Vista PRE, launched at the same time.

Alternatives

The Musical Fidelity M8s-700m is a bridged mono power amplifier rated at 700 W into 8 ohm, in a single 440 x 160 x 460 mm chassis weighing 30 kg.