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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
petg60
1,486 posts
 
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. 
lewm
13,120 posts
 
Pgastone, having written so much about how to adjust azimuth electronically, which is to say so that the measured crosstalk from one channel to another is minimized, I have come in my old age to agree with Mijostyn in that the net benefit of just having the stylus sit squarely in the groove is greater than the net benefit of minimizing crosstalk, if it means positioning the stylus tip asymmetrically in the groove. So I no longer mess around with ways to measure crosstalk.
stringreen's avatar
stringreen
6,472 posts
 
mijostyn.....I suspect you are way off. Most mirrors are silvered in the back and therefore you’ll have a great deal of error with the stylus resting on the glass with a few mm to the silver. If this is your tact, using a mirror from an old SLR camera.....you’ll have a much better chance of accuracy. I use the Fozgometer with its test record. Done a few times, with brand new batteries, the soundstage widened considerably...more depth, air, etc.  Be the way, I'm wiring the Foz at the output of the phono preamp.
Ag insider logo xs@2x
cleeds
5,960 posts
 
stringreen
mijostyn.....I suspect you are way off. Most mirrors are silvered in the back and therefore you’ll have a great deal of error with the stylus resting on the glass with a few mm to the silver.
Oh no, not at all. The distance between the silver and the stylus magnifies any alignment error, simplifying adjustment. If you use a gauge inscribed with a reference line - such as the original Wallytractor gauges - you can align the reference line with its reflection. That eliminates any parallax error and if the reference line then evenly bisects the reflection of the cantilever, you have achieved something very close to perfect tangency at the null point. That is exactly the advantage of using a mirrored gauge.
mrubey
36 posts
 
I find that all of the cartridge adjustments need to be optimized for the cartridge to truly express its potential. This is no less true of azimuth than any other parameter, including antiskate. I thought my cartridge was doing great when it was visually vertical. Then I found the by ear method using a mono record. Using that I found a spot that took my cartridge to the next level of presence and transparency. The reason a mono record is used is that it provides a more stable centralized point of focus in adjusting a stereo cartridge by ear. Using azimuth adustment, you will be able to move the center image to the right and left by moving the adjustment back and forth. When the mono center image of the stereo cartridge is dead center. Then in very subtle movements within that dead center area of adjustment there is a point of maximal focus, vividness and presence. This is the azimuth sweet spot. Peter Lederman points out two things regarding azimuth. First that if you have a cartridge with extraordinarily high separation, the separation is probably not perfectly electrically symmetrical and a meter will not give you perfect azimuth. The second thing is that high level Soundsmith cartridges are extremely sensitive to azimuth and that it’s worth it to take the time to find the sweet spot. In my experience this extrapolates to other correctly constructed cartridges.

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