I don't want to throw cold water on the Foz, but after reading the articles about the need to calibrate it and then noting that calibration is not exactly a simple matter, I am even more prone to stay away from it. Its accuracy depends upon the stability of the voltage from a 9V battery. First of all, I can say from having measured a number of new 9V batteries that the baseline "9V" is an approximation at best. They tend to deliver slightly more than 9V when new. Some can be at 9.2V, some at 9.4V, etc. From what I was able to glean, those tenths of a volt differences can affect calibration of the Foz. (One guy who responded to Fremer's blog noted that his Foz told him to tilt his cartridge by 15 degrees to obtain optimum crosstalk!!! Either his cartridge is grossly faulty or the Foz is way off, and odds are it's the latter.) So, it is a given that you need to calibrate every time you replace the batteries. Then there is the issue of the effect on calibration of voltage drift or corrosion on contacts or etc. I'd like it better if the battery fed a voltage regulator, but that might result in a prohibitive size for the Foz. Another option might be an outboard PS that plugs into the wall to power the Foz and delivers a well regulated constant 9VDC to it. That way, you calibrate once or at the factory, and forget it. I was surprised that Fremer documented so well the need for frequent calibration and then went on to confirm his strong endorsement. True, there is not much competition.
