A trio of CDs that allow you to compared mic preamps and microphones. Great for the home studio owner baffled by the choices for mic preamps and micrphones. NOTE: these are microphone preamps and microphones...not bass preamps.3D Pre CD vol 1 and 2 Mic Pre $105 value your for $50 http://www.3daudioinc.com/3daudio_prelp.html http://sales.3daudioinc.com/store/catalog.lasso 3D Pre CD Volume 1 The 3D Pre CD Volume 1 features 34 female vocal recordings in mono, using a Manley Reference microphone through 30 different preamps and 30 samples of a McPherson acoustic guitar, recorded in stereo using a Neumann KM-84 and an Audio-Technica 4033. The CD includes pictures from the 3D Preamp Listening Party, a complete list of the preamps, with URLs and pricing, a description of the testing procedure and a key to identify the preamps. 3D Pre CD Volume 2 The 3D Pre CD Volume 2, features 41 recordings of a 1953 Slingerland Radio King snare using a Shure SM-57 through over 30 different preamps, as well as 41 recordings of a male vocalist through a modified AKG C414B-ULS and a Manley Reference Cardioid microphone. The CD has pictures from the Listening Party, a complete list of preamps with URLs and pricing, and a key to identify the preamps. 3D Mic CD (new and unopened!) The 3D Mic CD features a male and a female vocalist singing through 49 different vocal mics, ranging from a Shure SM57 (under $100) to a Telefunken 251 (over $20,000). These high-resolution recordings (recorded at 24-bit, 88.2 kHz) will allow you to audition the largest collection of vocal mics ever assembled. Over 70 minutes of solo voice recordings (98 cuts) present each mic in a precisely calibrated setting so you can hear the differences for yourself in your studio on your monitors. Is one mic worth 200 times as much as another? You listen and decide for yourself. The CD includes a 16-page color insert with pictures of all the mics and the listening party, technical details of the testing, and the all-important key which identifies each mic. This is an invaluable resource for anyone who wants to learn more about microphones.