GFP-555

About the GFP-555

The Adcom GFP-555 is a high-end analog stereo preamplifier manufactured in the USA between 1985 and 1990. It features a straightforward design with six inputs and one preamp output, designed to complement Adcom's power amplifiers like the GFA-555. The unit includes a phono stage capable of handling moving magnet (MM) and low-output moving coil (MC) cartridges with a 100 ohm load and variable capacitance loading for MM. It offers a frequency response from 5Hz to 85kHz, total harmonic distortion of 0.003%, and a signal-to-noise ratio of 90dB for MM and 100dB for line inputs. The GFP-555 has tone controls including bass, treble, loudness contour, low and high filters, and a mono button. It lacks remote control but provides a simple, reliable user interface with tape monitor functions and dual outputs (one DC coupled for lab use). The chassis measures 432 x 289 x 76 mm and weighs 5.2 kg. It is favored for its clean, relaxed sound and solid build quality, making it a sensible choice for entry-level to mid-tier HiFi systems, especially when paired with Adcom amplifiers.