FM 255

FM 155 (top) and the true balanced FM 255 (bottom)
FM 155 (top) and the true balanced FM 255 (bottom)

The FM 255 was manufactured continuously for 11 years and has been the most successful of all preamplifiers/line stages thanks to its superb price/performance ratio.
The new MKII is a refinement of the original version with some additional features and fine ameliorations. Below the description of the earlier FM 255 which made audio history.

  • Proprietary enhanced Class A circuitry
  • CMRR of 95 dB (= 100-1000 times better than other so-called "balanced" equipment)
  • Featuring two true balanced inputs and three unbalanced inputs
  • Discrete Class A tape send and return guarantees superior recordings or connection to auxiliary equipment.
  • Unparalleled freedom from noise & interference
  • Tremendous headroom and reserves in input signal handling capability (+21dBv!)
  • Identical balanced input paths
  • All input & output impedances are perfectly linear over full frequency range
  • Sensors in the true balanced outputs automatically optimise performance
  • Fully discrete circuitry using special curve-tracer analysed and listening-selected semi-conductors
  • Outputs drive any load and long cables with perfect reproduction and stability
  • Precision balance and output level controls are used; no stepped attenuators, relay-type or inferior sounding optical or digital volume controls
  • Transformer utilises a special dual shield that prevents stray fields.
  • Extremely low impedance built-in power supply
  • Hand-selected and individually matched components of DIN, IEC & MIL standards
  • Totally modular concept guarantees that the FM 255 does not become obsolete
  • The Resolution Series ® 255 is THE ultimate precision preamplifier center for use with true-balanced, pseudo- balanced and unbalanced sources