Click here to purchase the entire book in PDF format. Reference Tape In order to calibrate your tape deck, you'll need to spend a little money first. You'll have to buy a calibration tape. This will not be cheap, but it will be worth the cost. A calibration tape is just a small reel of analog tape that has a bunch of test tones recorded on it. The thing that makes it special is that the test tones are absolutely guaranteed to be at a known level and recorded with proper alignment. This gives you a reference that you can use to calibrate your own tape deck. This is similar to owning an oscilloscope so that you know the voltage level of an output - a calibration tape lets you reference your recorder to some standard external device. At the risk of sounding like an advertisement, most people buy their calibration tapes from a company called Magnetic Reference Laboratories. They also have a good paper on their website that tells you how to calibrate your tape recording using a calibration tape. You can get that paper and order their tapes online at http://www.mrltapes.comwww.mrltapes.com.