The Sansui FR-D3 is an integrated amplifier that was released in the early 1980s by the Japanese audio equipment manufacturer, Sansui. This amplifier is part of the FR (Fuelise Reactor) series, which is known for its high-quality sound and sturdy build.The FR-D3 is a 2-channel amplifier that delivers 80 watts per channel into 8 ohms or 130 watts per channel into 4 ohms. It uses a BFR (Bi-Ferrite Reactor) output stage that is intended to provide a high current drive to the speaker, resulting in a more powerful and dynamic sound.The FR-D3 also features a heavy-duty transformer, which provides a stable and low-noise power supply to the amplifier. It has a frequency response of 10Hz to 100kHz (-3 dB), a signal-to-noise ratio of over 80 dB, and a total harmonic distortion of less than 0.25%.The input stage of the FR-D3 uses discrete components to ensure a clear and detailed sound. The volume control is a high-quality aluminum potentiometer that provides precise and smooth volume adjustment.Overall, the Sansui FR-D3 is a well-regarded amplifier that is known for its warm and musical sound. It is considered a classic in the audio enthusiast community and still commands a premium price in the vintage audio market.