Jimbos Audio ramblings

[Barry]

£450 for essentially a differential amplifier (read common or garden op-amp), a switch, and a meter! I'm sure such a device could be built for under £50.

[Barry]

The very kind Jamie sent me a PM so I could call him so he could explain. Once I got the issue it is obvious what he is saying is true. I will try and explain for all to understand.

Hold your right arm out parallel to the ground with your right palm facing the ground, then bend your elbow to make a right angle to your upper arm keeping you arm level to the ground. Now cant your right hand out at the wrist to the right keeping it parallel to the ground, think of your hand as the head shell, and you arm as the tonearm. Now here is the interesting bit. Keep your hand fixed where it is and raise you elbow vertically, watch your hand as you do so, and you should see your hand rotates with your little finger going up and your thumb going down. If you lower your elbow then the opposite occurs. This demonstrates what happens when you raise and lower a tonearm at the pivot point, it creates a twist at the head shell which will alter the Azimuth, what ever it was set to. This is not immediately obvious when adjusting the arm, but this demonstration clearly highlights the issue.

So as Jamie(karma1967) rightly says if you change the VTA/SRA of your tonearm you need to reset the Azimuth afterwards to ensure that the stylus is correctly set up in the groove.

That description only applies to tonearms where the bearings for motion in the vertical plane are not at right angles to a line passing through the headshell and cantilever. I know of only two makes of tonearm where this applies: SME (excluding the cast magnesium models) and Fidelity Research.

I used to wonder about this, as when the arm/cartridge rides a warp, the cartridge will 'roll' slightly counterclockwise when viewed from the front, so upsetting azimuth. However I did some calculations based on the dimensions and geometry of my SME M12-R arm and the effect on crosstalk, and even with a 5mm warp the crosstalk was insignificant.

[Wakefield Turntables]

£450 for essentially a differential amplifier (read common or garden op-amp), a switch, and a meter! I'm sure such a device could be built for under £50.

Your more than probably correct, however, I have one, I don't have to worry about buggering about making one and I know it works which probably adds a few less grey hairs in my beard.

PS I paid nowhere near £450.

[Jimbo]

Hello Gentlemen, do you means this old thing ?



My, this thread moves quickly. Yes the Fozgometer is a piece of cake to use. It works best with detachable head shells, you can still go nuts trying to set channel seperation up on fixed head shell tonearms like my SME V-12, so, I prefer using my SME 3012. You still have to pay close attention to cartridge set up, this device very very quickly enables you to see how much of a balls-up you've made.

That's the Gizmo Andy!

[Jimbo]

i'd rather buy the polished turd its a cant win scenario trying for perfection; just use your eyes and ears
it usually works too

[walpurgis]

'Fozgometer' is an odd name. Was the device designed by a Mr. Fozgo?

[Pigmy Pony]

'Fozgometer' is an odd name. Was the device designed by a Mr. Fozgo?

Hi, it's me!

[karma1967]

That description only applies to tonearms where the bearings for motion in the vertical plane are not at right angles to a line passing through the headshell and cantilever. I know of only two makes of tonearm where this applies: SME (excluding the cast magnesium models) and Fidelity Research.

I used to wonder about this, as when the arm/cartridge rides a warp, the cartridge will 'roll' slightly counterclockwise when viewed from the front, so upsetting azimuth. However I did some calculations based on the dimensions and geometry of my SME M12-R arm and the effect on crosstalk, and even with a 5mm warp the crosstalk was insignificant.

By jingo i think your right barry,i've just checked my arm and if i understand correctly what you said above then a line drawn from the centre point of my bearings and at 90 degrees to them ends up running parallel to the headshell,so again if i understand correctly them my cartridge wont tilt to the left or right when moving the arm up or down.

i stand corrected said the man in the orthopedic shoes!

[struth]

'Fozgometer' is an odd name. Was the device designed by a Mr. Fozgo?

was made by a guy called fosgate. his nickname was foz..

[Jimbo]

Another way of checking Azimuth which I appreciate is a bit rough and ready is find a test track that has some extreme left and right information in the recording. This will tell you if the cartridge is tracking left and right channels well. I use Andrea Vollenweider album "The Magic Cave". At the beginning when they enter the cave you hear drops echoing in the cave which are to the extreme left and right in your speakers. Its also an amazing track if you want to hear extreme depth in a recording. Quite spooky. It will tell you a lot about your cartridge set up and is very well recorded.