TDK's Ultimate Guide To Recording From CDs to CASSETTES Non-music - Contains test tones and reference signals for better recording onto TDK blank cassettes CDK 0100, brand new and factory-sealed in the original shrink wrap This is an extract from an extremely useful review (and tips) of this item by "vqworks" This CD includes a set of test tones that is ambitiously intended to enable users to very quickly set recording levels according to musical genre and TDK tape formulation (SA, SA-X, or MA). What limits the usefulness of these tones is that they apply only to the TDK formulations of 1990 through 1991. The tones do not work as well with TDK formulations from older and newer years because of their different overload/distortion characteristics. Also, while the recording level instructions state that the user should set the recording level to display "0 dB" on the deck's meters when monitoring a test tone, this is not necessarily an accurate practice because the number scales on meters are arbitrarily set by manufacturers. And even then variations in meter calibration exist between models within the same brand! A better instruction would be to use the aforementioned "0 dB" indication only if no Dolby symbol (Double-D logo) exists on the meters. This Dolby symbol is referenced to an absolute level so it is better to refer to this instead. When Dolby level is used as a reference, the recording level should be set 2 dB higher, which equals the official 0 dB DIN level. Moreover, the tones themselves cannot and do not account for the loathsome practice of dynamic range limiting (extreme volume compression between soft and loud passages of music) that many producer-mandated studio recording engineers performed beginning in the early 90s. Coverage on noise reduction is also a bit on the sketchy side, especially when dbx noise reduction is not covered at all. Still, TDK has to be given a lot of credit for releasing an ambitious recording aid. Be that as it may, TDK has been sold a few years ago to Verbatim so TDK is really history. Like I said, this CD is a good buy for posterity or nostalgia. This item has never been opened ! Shipping everyday.