Fozgometer

Stringreen, you shouldn't have to adjust VTF or VTA/SRA or alignment when adjusting azimuth. All of those parameters should be been set and locked in before you adjust azimuth.

If you have a tonearm that uses a set screw to adjust azimuth then yes, you could be affecting tonearm length if the arm tube is somehow pushed or pulled in or out of the tube sleeve. But all you have to do is put a very small drop of "White Out" on the arm tube right at the edge of the sleeve. That provides a reference marking to make sure you aren't moving the arm tube in/out as you tilt it to adjust for azimuth.

Regards,
Tom

Tom...I'm using a VPI 3D arm, and can tell you that when moving either counterweight or CounterIntuitive around the arm tube..even slightly, I can't prevent it from moving front/back..even a miniscule amount which changes VTF. I must check and check again all the parameters. ...and when adjusting the vtf, I must again check the Foz for its indication. When I'm doing this, it seems endless, but I eventually zero it in. White out indications et al, are way too broad and inexact for me.

Stringreen, you're description of setting azimuth on a VPI uni-pivot doesn't motivate me to try one out. If VTF is directly coupled with azimuth adjustments and is that fidgety, I think I'll stay with gimbal-pivot tonearms. :-)

So to clarify that there shouldn't be a need to adjust VTA/SRA and VTF when setting azimuth: IF arm length and VTF are stable while adjusting azimuth, having to tilt the cartridge even 1 to 2 degrees will only change height by ~0.05mm to ~0.10mm from a reference vertical stylus setting. I've measured record thickness differences greater than that on a single LP, let alone the differences in thickness between LPs.

Enjoy the music!

Tom

Ooops, that's "your" description. I had started with a different train of thought and then changed everything but "you're". 8-)

There are two schools of thought with regard to the endpoint of azimuth adjustment. One says to go for the least amount of crosstalk, in which case I have found over many years (using the Signet Cartridge Analyzer which reads out in "db") that the amount of crosstalk will not be equal in both channels. The other says to go for equal amounts of crosstalk in both channels, even if in doing so you have to sacrifice the absolute best values for crosstalk, which is nearly always the case. There is no right or wrong in choosing either endpoint.

I presume the Foz reads crosstalk at 1kHz. Yes? If so, what do the numbers "17" and "19" mean? If the readout is in db, then it is usually a negative number indicating the level of crosstalk below 0 db, when the channel being measured is set to 0 db. In that case, one typically sees better than -20db at 1kHz (meaning a number more negative than -20).