SIT-5

About the SIT-5

The SIT-5 is the latest monoblock amplifier from First Watt, the fifth model employing a Static Induction Transistor (SIT) as the core amplifying device. It uses a Tokin THF51S SIT rated at 600V, 30A, 400W with 50 MHz frequency response, operated in Common-Drain (follower) mode without feedback. The design features a single-ended Class A output stage with a P-channel MOSFET for bias current, push-pull voltage gain stage, custom output transformers, balanced and unbalanced inputs, soft-start power supply, aluminum chassis, and user-adjustable bias. It succeeds models like SIT-1 to SIT-4, offering higher power for less efficient or lower impedance speakers compared to SIT-4.