System and method for generating an amplitude error signal in a magnetic tape recording channel

A method, comprising:

• receiving an output of an equalizer;
• and
• comparing a magnitude of the output to a saturation threshold level;
• if the output is higher than the saturation threshold level, generating a gain error, wherein the gain error is a fixed value.

A method, comprising:

• receiving an output of an equalizer;
• generating a threshold qualified peak from the equalizer output and a tracking threshold level;
• comparing the threshold qualified peak to a second threshold;
• generating a gain error based on the comparison;
• and
• using the gain error to adjust a gain of an analog signal.

A system for generating gain errors, comprising:

• a circuit for receiving an output of an equalizer;
• a circuit for comparing a magnitude of the output to a saturation threshold level;
• a circuit for generating a first gain error if the output is higher than the saturation threshold level;
• and
• either a slicer or a trellis for generating a second gain error, wherein the slicer generates a gain error based on an output of an interpolator, wherein the trellis generates a gain error based on an output of a maximum likelihood detector.

A system for generating gain errors, comprising:

• a circuit for receiving an output of an equalizer;
• and
• a circuit for comparing a magnitude of the output to a saturation threshold level;
• a circuit for generating a first gain error if the output is higher than the saturation threshold level;
• a circuit for generating a threshold qualified peak from the equalizer output and a tracking threshold level;
• a circuit for comparing the threshold qualified peak to a second threshold;
• and
• a circuit for generating a third gain error based on the comparison of the threshold qualified peak and the second threshold.