The frequency response of the post-emphasis circuit in a tape recorder. The C.C.I.R. and the N.A.B. have both published recommended reproducing characteristics.
"My son found a rare 45 copy of a band I used to be in almost 50 years ago. He purchased it on Ebay. Somehow it had found a following in Europe. It did have a few scratches and pops but after the clean-up and audio restoration done by LP2CD I was amazed. We recorded that when 16 track analog tape recording was a big deal. The fidelity was ..."