Like the Xs 300, the Xs 150 was developed through constant and thorough innovation. After years of SIT device experimentation—followed by real-world deployment in Nelson's First Watt designs—our circuit modifications capture the unique, tube-like sonic footprint of SITs using the higher-output MOSFET devices in the Xs series. The result is unparalleled, fatigue-free listening enjoyment.

At a glance

• Class / Type: Class A, Mono
• Gain: 26 dB | Inputs: XLR / RCA
• Power Output: 150 W/8 Ω (per channel)
• Output Devices: 112 (per channel)
• Power Consumption: 700 W (active) | <1 W (standby)
• Chassis: 2
• Dimensions (per chassis): 19″ W × 21.5″ D × 11″ H
• Weight (per chassis): 102 lbs / 132 lbs

The Xs 150 delivers the color and ease of classic SIT voicing with the drive and bandwidth of modern Class A—built for long, happy sessions.