SIT-2

About the SIT-2

The First Watt SIT-2 is a stereo single-ended Class A power amplifier delivering about 10 watts per channel into 8 ohms using a single Static Induction Transistor (SIT) gain device per channel. It uses a single gain stage with both voltage and current gain, built with minimal parts and no global feedback, to emphasize simplicity and low-order harmonic character. The SIT device is a custom Silicon Carbide power JFET designed to emulate key transfer characteristics of triode vacuum tubes, giving a triode-like harmonic structure without using actual tubes. The SIT-2 accepts single-ended (RCA) inputs and is intended for 4-16 ohm loudspeakers, but is best matched with high-efficiency speakers of roughly 8 ohm nominal impedance and benign impedance curves due to its low output power. Typical gain is approximately 18 dB, input impedance 10 kohm in direct mode, and the amplifier draws about 200 watts from the mains in normal operation. It runs wide-bandwidth with very low loop complexity; published and independent measurements indicate a frequency response extending well beyond the audio band and low single-digit percent total harmonic distortion at rated power, dominated by second-order harmonics for a more tube-like presentation.