Интегральные усилители — Naim NAIT 5SI

The NAIT 5si is the entry point to the integrated amplifier range of Naim Audio, the British company based in Salisbury, England. Naim launched it alongside the NAIT XS 2 and SUPERNAIT 2 as the next step of a line that began with the original NAIT of 1983, and the company states that the 5si holds the same position in its catalogue that the first NAIT held, with the brief to get the most performance out of a simple, efficient and reliable design. The model has since been withdrawn from the Naim catalogue.

Key specs that matter

The power amplifier is rated at 60 W per channel into 8 ohm and 90 W per channel into 4 ohm. Four line inputs are provided - two that accept either DIN or RCA plugs and two RCA-only pairs - and each is sized for 2 V sources, with a working range of 0.5 to 5.0 V and an input sensitivity of 170 mV. A fixed-level HDD output on RCA delivers 170 mV from a 470 ohm source impedance for recording, and a 6.35 mm TRS socket on the front feeds headphones. Quiescent consumption is 19 VA and maximum draw 300 VA, with mains options of 100, 115 or 230 V at 50 or 60 Hz and an off-mode figure under 0.3 W. The chassis measures 432 mm wide, 70 mm high and 301 mm deep, and the weight is 6.8 kg.

Engineering and use context

The 5si received a newly designed headphone amplifier, and Naim says it borrows a number of circuit technologies from elsewhere in its product range. As with the other NAIT models of that generation, an over-sized toroidal transformer feeds the supply rails, and the enclosure is non-magnetic aluminium with shoulder bolts intended to drain away unwanted vibration. An AV bypass mode lets the amplifier sit inside a home cinema setup, so a surround processor can drive the front channels at a fixed gain. The case and front panel are black powder coated, the supplied handset is the NARCOM-4 infrared remote using the RC5 protocol, and a Power-Line Lite mains cable comes in the box. While the NAIT XS 2 and SUPERNAIT 2 list FlatCap, HiCap or SuperCap supply upgrades, the 5si specification names none.

Pairing

Naim suggested the matching CD5si disc player as the partner source, and any line-level streamer or DAC will fit the inputs. There is no built-in phono stage, and a turntable must be connected via an outboard RIAA stage. Speakers with a low nominal impedance are a practical load, given the extra power the amplifier delivers into lower impedances.

Alternatives

The Naim NAIT XS 3 sits one step higher in the range with 70 W per channel into 8 ohm and fitted with a moving magnet phono input.