3155

About the 3155

The NAD 3155, launched in January 1985, is a flagship integrated amplifier that NAD marketed as "two products in one." As a preamplifier, it matches separate audiophile preamps in sonic performance while offering superior operating flexibility. As a power amplifier, it drives difficult loudspeakers to high volume levels with clean, distortion-free sound. The amplifier features a warm, expansive, and punchy sonic character with solid bass response and a sweet-sounding midrange reminiscent of valve amplifiers. The phono section was upgraded with ten specially selected transistors per channel, a differential FET input circuit, and a custom-wound input filter. A separate high-gain moving coil stage uses ultra-low noise transistors with switchable impedance, achieving a claimed 107dB dynamic range. The amplifier includes NAD's Soft Clipping circuit for speaker protection and an impedance matching switch that reconfigures the amp between 4Ω and 8Ω loads. It can be used as a dedicated preamplifier or power amplifier alone, and supports bridged mono operation when paired with a NAD 2155 power amplifier for 150W RMS output. The unit is housed in a wider 420x108x380mm case with new design language and smaller switchgear.