What does it mean to “align” a tape machine?
There are a number of standard adjustments on any analogue tape machine, which can roughly be broken up into mechanical and electronic adjustments. The mechanical adjustments include the head position (height, skew, and azimuth), and sometimes tape speed. Incorrect head height will result in poor S/N and leakage between channels, because the tracks on the head do not match up exactly with those on the tape. Incorrect tape skew will result in level differences between channels and uneven head wear, because there is more pressure on the top of the head than the bottom (or vice versa). Incorrect azimuth will result in loss of high frequency response and strange skewing of the stereo image. Tape speed error will result in tonal shifts. Although on many machines with capstan speed controlled by crystal or line frequency, it is not adjustable. Electronic adjustments include level and bias adjustments for each channel. Some machines may have bias frequency adjustments, equalization adjustment
