Hi Roger, Doug ...
The fascinating revelation for me was the discovery of multiple null points (false nulls) which brought me no comfort in the least. I believe I described this in a recent thread (this one?).
Failing instrumentation, we're left with starting out with a headshell that's parallel to the record surface (in the azimuth plane), and beginning our adjustments from this point.
The is a leap of faith that the cantilever/stylus assembly is within reasonable manufacturing tolerances so that the null you hit (by ear) is the real one. The thing we have going for us is that minimal crosstalk will also yield the lowest distortion, because the stylus will be sitting squarely in the groove.
If you're troubled that perhaps you are one null away from the truth, then you can always go counter clockwise by one null and also clockwise by one.
Rather than reiterate Brian Kearn's brilliant post you pointed the group to, I suggest that everyone take a moment read it. Even if the math confuses you, I suggest you read it and file it away for future reference. Come back to it from time to time. You'll be amazed at how things like this begin to make sense over time.
One key point to focus on is midway into this post, where Brian hits the nail squarely on the head:
"I disagree with this method of calculating crosstalk. It does not take into account the effect of channel imbalance on the crosstalk measurement. In effect this method assumes that a cartridge has perfect channel balance."
Cheers,
Thom @ Galibier
The fascinating revelation for me was the discovery of multiple null points (false nulls) which brought me no comfort in the least. I believe I described this in a recent thread (this one?).
Failing instrumentation, we're left with starting out with a headshell that's parallel to the record surface (in the azimuth plane), and beginning our adjustments from this point.
The is a leap of faith that the cantilever/stylus assembly is within reasonable manufacturing tolerances so that the null you hit (by ear) is the real one. The thing we have going for us is that minimal crosstalk will also yield the lowest distortion, because the stylus will be sitting squarely in the groove.
If you're troubled that perhaps you are one null away from the truth, then you can always go counter clockwise by one null and also clockwise by one.
Rather than reiterate Brian Kearn's brilliant post you pointed the group to, I suggest that everyone take a moment read it. Even if the math confuses you, I suggest you read it and file it away for future reference. Come back to it from time to time. You'll be amazed at how things like this begin to make sense over time.
One key point to focus on is midway into this post, where Brian hits the nail squarely on the head:
"I disagree with this method of calculating crosstalk. It does not take into account the effect of channel imbalance on the crosstalk measurement. In effect this method assumes that a cartridge has perfect channel balance."
Cheers,
Thom @ Galibier