Cartridge azimuth adjustment using a voltmeter and a test lp


Hello all,
I know that azimuth adjustment comes up often as do the various methods to get it right- or close to right.  I have been doing a lot of reading on the subject and I realize that using a voltmeter with a test lp has its flaws vs using other techniques that use sophisticated instruments and magnification to physically determine if the stylus is perpendicular to the record surface.  Nonetheless I would like try using a voltmeter to see how this compares to how I have the cartridge currently set up- but I have a question:
The generally accepted method is to use the amplifier output terminal to measure the voltage output of the test lp- but would it be a problem to measure the voltage at the speaker terminals?  Even with the interaction of the speaker cables the voltage variation at the amp terminal vs the speaker terminal should be very minor.  But I have seen in some posts that some suggest it is better (or necessary) to measure at the amp terminals.  Why?
Arguably, if cable and other circuit interference were such an issue then it would make more sense to measure the voltage at the tonearm terminal for the phono cables, assuming the voltmeter has the necessary range to measure such a low voltage output.

The reason I ask is that reaching behind my amps, pass labs xa60.5 mono's, would be a real pain and if the measurement has to be taken at the amp output I would like to understand why.

Many thanks for your advice.

System: Thiel 3.7's, or Magico S1 mk1,  Pass Labs xa60.5 mono's, Vinnie Rossi LIO preamp (slagle AVC passive mode) or Prima Luna Dialogue Premium preamp, Moon 280 Dac, PS Audio Stellar phono, VPI Aries 1 turntable/JMW 10 tonearm with Lyra Delos cartridge, Nordost Heimdall 2 cabling.
pgastone

Showing 1 response by petg60

Hi,
my understnding is that cartridges with low to middle seperation figures are more affected by incorrect azimuth compared to ones with high figures. Reason behind is that a high seperation cartridge even if loosing some db of incorrect azimuth will still maintain high figures. I do not imply that azimuth should be overlooked but in my opinion is not the top priority in cartridge alignment. Having so much off centre image, as mentinoed above is not only the outcome of incorrect azimuth but HTA would be way off, or in case of a tubed phono tubes mu is not closely matched (just mentioning 2 factors). All methods stated above are a fine way of checking/adjusting azimuth but practically we are talking of minor vertical adjustment (if it is too high change the cartridge or the arm). In the end a mirror for checking would be fine to have at least the min db loss.