ZYX Universe - Unipivot or Dual Gimbal arm

Hi Roger,
The reason for the (in some, not all cases)existence of more than one "null" point is the fact that azimuth(crosstalk symmetry) is usually perfected for one frequency only! When you look at the crosstalk figures versus frequency plots of most high quality carts(if such a plot is provided), you will note that the l/r channel curves for the crosstalk are rarely, if ever congruent. As a result you could achieve perfect symmetry for 1kHz(that's the frequency used on many test records) and an uneven figure for, say, 4kHz . Now which is the correct one?
The dhfi "Hörtest-und Meßplatte 2"(long out of print) has crosstalk tests for 125, 500, 1000, 5000 and 10000Hz. This is what I check my "azimuth by ear" adjustment against frequently. When you adjust azimuth by listening it takes all frequencies into account...
BTW,Wally is right, more than 2° tilt to get even(or maximized) crosstalk figures is unacceptable.

I hope this doesn't cause even greater confusion...

Cheerio,

Frank

This may just reiterate what Doug, and perhaps others, have said, but I am not certain that Wally's Azimuth tool is all that necessary. I shared in that tool for a time and on each of four different arms which I had previously set by eye ball - all were well within the 5% electrical readings range as suggested by Wally. In a couple of instances it sounded better a bit further from "balanced" than at exactly balanced. As such, I feel that “macroing” it by eye, followed by “microing” by ear is the ticket to azimuth.

Hello Frank,

Thank you for your explanation. Noncongruence of the cartridge frequency response at different frequencies makes perfect sense. What we really need is a test record that has pink noise in the left and right channels. Until then I guess our ears are the best test tool. However, I suspect that I will still need to use the 1kHz test tone and the voltmeter to get close to the ideal spot and then fine tune by ear.

In your experience, for the best cartridges, have you found the overall "best spot" to be very far from the 1kHz "best spot"?

Best Regards,

Roger

Hi Guys,

I had another chat with Wally. Using pink noise as a test tone for setting azimuth will not work. Pink noise is random. Thus, the volume constantly changes and you will not be able to get a constant reading on your voltmeter. Though if you had a sophisticated meter that could average the reading over many seconds, then it might be possible to use pink noise.

Wally was also of the opinion that it is more important to have the azimuth correct at 1000Hz, rather than 400Hz or 5000Hz. This is because the midrange is where human hearing is most sensitive. Yes, you can measure at 400Hz, 1000 Hz and 5000 Hz. That will create a range of settings for you. However, you will need to determine by ear where in that range of settings is the “best” setting. Wally’s belief is that the “best” setting in that range determined by ear will be very near the optimal 1000Hz setting determined with a voltmeter and test tones.

Wally also mentioned that it is very difficult to set azimuth by visually aligning the cartridge body. Tilting the cartridge body by .25 degrees changes crosstalk by 2dB and changes the relative heights of the left and right sides of a 20mm wide cartridge by .1mm. Tilting by .4 degrees makes a 3dB change in crosstalk and a .15mm change in relative height, left to right. Tilting by 1.0 degree changes crosstalk by 6dB and changes relative heights by .333mm. So a very small change in tilt, visually indiscernible, can have an clearly audible effect on sound.

More food for thought.

Best Regards,

Roger

All this food for thought and not a spoon in sight!?!