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F1J

Name: First Watt F1J
Brand: First Watt

First Watt

2010 – Present

AmplifiersPower Amplifiers

Estimated price (community-sourced)

$1,800

About the F1J

The First Watt F1J is an updated version of the acclaimed F1 power amplifier, designed by Nelson Pass. It operates as a current source amplifier rather than a conventional voltage amplifier, delivering 10 watts per channel in pure single-ended Class A operation without feedback. The F1J replaces the original F1's gain MOSFET transistors with state-of-the-art power JFET devices, resulting in improved high-frequency distortion performance, extended bandwidth, and approximately 1.5 dB more gain. The amplifier is specifically optimized for sensitive full-range loudspeaker drivers and offers exceptional clarity, transparency, and control over speaker voice coils. Each channel draws a constant 100 watts, and the amplifier features both balanced XLR and single-ended RCA inputs. The F1J is recommended for use with preamps having ordinary to low output resistance for optimal high-frequency performance.

Specifications

Key Specifications

Power: 10W

Full structured specifications are available to members.

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