Fozgometer

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).

Lew, the manual states that channel separation is what's being measured. Also: "The readings are virtually independent of overall signal levels, and can be made with a wide range of input signals without effecting accuracy."

So your comment about what correct azimuth entails is consistent with using the Fozgometer for alignment. Try to get both the best balance between channels and the highest separation in each channel. As you also mention, the two are probably synonymous in a perfect world, but I've found that sometimes it's a compromise between the best separation and the best balance. But which should have priority is not clear to me and I've biased the alignment in favor of trying to get channel separation in better balance while maintaining the best separation value in the lower of the two channels. Does that seem reasonable? (Reasonable or not, it sounds mighty fine. :-)

It would be helpful if Mr. Fosgate and Musical Surroundings were a bit more thorough in describing what the goals are and how to get there.

Regards,
Tom