Naim NAP 155 XS Power Amplifier

Naim NAP 155 XS Power Amplifier

The NAP 155 XS is the entry point into the separate power amplifier range from Naim, and forms the most cost effective of the XS models. Constructed from slimline alloy casework for electromagnetic screening and durability, the NAP155XS is the perfect match for the NAC155XS pre-amplifier.

The foundation of any quality power amplifier is the size and capacity of it's DC power supply - an amplifiers job is to modulate the power consumed from the mains supply in harmony with the audio input signal, so any deficiencies in the power supply area will compromise performance. The NAP155XS is built according to well established Naim practices with a very large toroidal transformer feeding dual bridge rectifiers and a bank of high capacitance reservoir capacitors, enabling the loudspeakers to draw large transient currents if necessary during musical peaks. The NAP155XS has separate transformer windings for both left and right hand power amp channels, as well as a separate winding and power supply to feed the NAP155XS pre-amp.

High current NPN output transistors run in class AB mode for both efficiency and linearity are bolted to a castellated aluminium heat sink for efficient heat removal, whilst additional thermal protection is provided to a case mounted thermistor which detects over temperature hazards and shuts the amplifier down if necessary. A symmetrical amplifier circuit with thermally tracked differential input pair transistors is very linear, producing very little distortion and high slew rate. Hum and noise are vanishingly low at all power output levels right up to 60W into 8 ohms.

On the rear panel is the mains on/off switch and fused IEC mains input, twin loudspeaker outputs accepting 4mm binding posts, a four pin DIN audio input and a 24V dc power output suitable for powering the NAC 155 XS.