I know, this has been discussed a couple of times, since many rare and sought after CDs (Toshiba's Black Triangle, like "Abbey Road", early Japanese CD pressings, like "The Wall", etc.) are recorded with pre-emphasis. Still, the results, what exactly is the correct de-emphasis EQ curve to use for ripped waveforms (unless you are using a Mac where some progs are reported to de-emph “on the fly”), were either not satisfactory when listened to and/or not quite clear. To find out the “ultimate truth”, I measured the de-emphasis curve on the analogue output of the Sony NS999ES SACD/CD player with a self-generated reference White Noise CD burnt with pre-emphasis flag set. No matter what, here is how Sony does de-emphasis "in ES hardware" (see attached image). Well, it looked quite different from the other (almost linear frequency cut-off) "de-emphasis definitions " found on the Internet. Digging on that deeper I came across a couple of interesting threads, http://www.solorb.com/dat-heads/digests/V5.400/D469#Msg1 http://www.solorb.com/dat-heads/digests/V4.100/D191#Msg3 at last explaining CD/DAT de-emphasis (for the first time I saw) correctly. Reportedly, the "Sound Recording Handbook" by John M. Woram Publisher: Howard W. Sams & Co; 1st ed edition (August 1989) ISBN: 0672225832 (http://www.amazon.com/gp/product/0672225832/) explains in detail how the CD/DAT pre-emphasis/de-emphasis works. In a nutshell: to generate the correct target 15/50µs EIAJ de-emphasis (or pre-emphasis) curve for CD/DAT use the following equation: DE(f) = 10*log(A/B)-10.4576 PRE(f) = 10*log(B/A)-0.9684 DE(f) - de-emphasis output in dB at a frequency of f Hz PRE(f) - pre-emphasis output in dB a frequency of f Hz Where: f = frequency in Hz A = 1 + 1/(H x H) B = 1 + 1/(L x L) H = (2 x pi x f x t(H)) L = (2 x pi x f x t(L)) t(H) = high freq. time-const (15 µs = 0.000015) t(L) = low freq. time-const (50 µs = 0.000050) pi = 3.1416 An Excel calculator is available at http://www.radonmaster.de/robernd/demp_tab.xls Here are some EQ reference points I generated and used for Toshiba Black Triangle "Abbey Road" or Japanse Pink Floyd "The Wall" (generated wavs - for best results: 24bit/96kHz - sound just right and just beautiful! At last!) Code: Freq. De-Emphasis (CD/DAT) 510 Hz -0.1 dB 726 Hz -0.2 dB 896 Hz -0.3 dB 1042 Hz -0.4 dB 1173 Hz -0.5 dB 1294 Hz -0.6 dB 1408 Hz -0.7 dB 1516 Hz -0.8 dB 1620 Hz -0.9 dB 1720 Hz -1.0 dB 2188 Hz -1.5 dB 2629 Hz -2.0 dB 3064 Hz -2.5 dB 3506 Hz -3.0 dB 3965 Hz -3.5 dB 4449 Hz -4.0 dB 4968 Hz -4.5 dB 5534 Hz -5.0 dB 6159 Hz -5.5 dB 6861 Hz -6.0 dB 7664 Hz -6.5 dB 8605 Hz -7.0 dB 9739 Hz -7.5 dB 11157 Hz -8.0 dB 13029 Hz -8.5 dB 15708 Hz -9.0 dB 20128 Hz -9.5 dB 21427 Hz -9.6 dB 30195 Hz -10.0 dB 96000 Hz -10.4 dB At last it works as it should! And it exactly matches how Sony NS999ES SACD player de-emphasizes CDs on the analogue output, from what I measured. I am so glad I found it out now. Thought this info might be useful for some other folks out there, too. You never stop learning!