Azimuth

I recently managed to acquire a Fozgometer to test azimuth when setting up my cartridges. It’s a pretty handy tool actually.

“Azimuth refers to the horizontal balance of the cartridge when viewed from the front. This, in turn, determines at which angle the stylus sits on the record groove. The theoretical assumption is that when the cartridge is perfectly perpendicular to the record groove, the stylus will sit perfectly in the record grooves.”

Mine is the original version, and it does a good enough job for me.

I also got a copy of the Analogue Productions “Ultimate Analogue Test LP”. This is essential as it has seperate left and right channel tracks to actually be able to compare the output of the left and right channels, and hence measure the azimuth with the Fozgometer.

“If azimuth is set incorrectly, the stylus will not sit perfectly in the record groove, signals recorded on the left channel will leak to the right channel, (or vice versa), this is leakage between channels is called crosstalk, and it is expressed as a negative decibel number. The higher the negative number, the lower the crosstalk, the better the channel separation.

All cartridge will have some inherent crosstalk, high-quality cartridges will usually have a crosstalk above -30dB for both channels, whereas the average cartridge will usually have a crosstalk between -25 to -30 dB.”

I used to use an acrylic block with lines inscribed into it to set azimuth, and it is a pretty good way of getting a ballpark level of accuracy. The Fozgometer is really very precise and obvious. Now whether you can hear a slight channel imbalance or minor levels of cross talk is another thing. And even if you can hear it, would you really care?

There’s a very interesting dissertation on azimuth on the Korf Audio blog that is worth reading.