Analog Magic Question

"In theory it should if the effective mass is low enough to render the resonance frequency of the combination using an LVB is in the 8-12 db range in both planes."

As I am sure you know, frequency is measured in Hz, not in db. So it might seem you meant to write that the amplitude of the resonance is 8-12db. But the desired resonant frequency is also said to be in the 8-12Hz range.  So I wonder what you actually meant to say.

Also, further up the thread, you wrote "Azimuth L to R. 0.03% difference (note my VTA adjuster is frozen but visually it looks OK)". What does that mean? Does it mean that there was a .03% difference in interchannel crosstalk, in terms of db?  That is a very very tiny difference that I doubt can be measured reliably.

Some months or a few years ago, Dave Slagle was at my house, and he adjusted my ART7 cartridge to correct for its zenith error. To do that, he had with him a laptop with some sort of measuring program on it. But also we listened after each tweaking of zenith (made by twisting the cartridge in the headshell).  There was a profound positive difference both aurally and by computer measurement, when he got the zenith optimized.  I was really rather amazed. Since then, that headshell and that cartridge are permanently mated, so far as I am concerned.

Hi lewm,

It was late when I keyed that message.  Sorry for my confusion.  Yes the correct unit of measure for resonance is Hz. The actual measured values for the azimuth are 0.45 (left) and 0.48 (right).  These were the best (closest to each other) values obtainable after a lot of fiddling.  

Bill

The actual measured values for the azimuth are 0.45 (left) and 0.48 (right). 

That can’t be correct. For this test you are playing a 1 KHz tone in one channel and measuring how much lower it is in the other channel. Lower is negative dB. 

-20dB is 10 times less and not so good

-30db is about 32 times less and what better cartridges can do, or close to it

-40dB is 100 times less and very unusual as well as very, very good

You should typically be getting readings in the minus 25-30 dB range. The goal is for them to be as close together as possible with about .5dB difference pretty good. So for instance -27.7dB for L and -28.1dB for R would be .4dB difference so pretty good. The numbers you stated make no sense. 

https://www.analogmagik.com/azimuth

Some months or a few years ago, Dave Slagle was at my house, and he adjusted my ART7 cartridge to correct for its zenith error. To do that, he had with him a laptop with some sort of measuring program on it. 

I assume Dave was using Analog Magik and using the VTA test if he has version 1. He has discussed this over at What’s Best.  Version 2 has a Zenith test but I have V1 so haven’t used it. For V1 measure distortion with the VTA track, twist and measure until you get it as low and even as you can. Typically starting closer to 10% after aligning visually, I’ve found 2-3% to be really good.

@herman 

The numbers I provided are the IM distortion values.  I did not record the db difference values, but will go back and do so later today and post them.  I have a PT appointment this morning, recovering from knee replacement surgery, so I can't do it right now and it is not trivial to set up the test for me.  In the meantime please look at Tutorial #9 as I believe it will end your misunderstanding.

I read the tutorial. V2 works a bit differently than V1, but what I stated about azimuth is true nonetheless.

For azimuth, the goal is to minimize crosstalk and to make it equal in both channels as I described.

For VTA, the goal is to minimize distortion.

While VTA and azimuth are interrelated, they are different. You stated the distortion you measured which is an indication of optimized VTA. . This does not mean you optimized azimuth by minimizing and making crosstalk equal.

From the tutorial. which states what I did about azimuth. I am not misunderstanding anything.

AnalogMagik allows users to determine optimal azimuth angle by measuring the crosstalk between Left and Right channel.  Optimal position is achieved when the two numbers are as close together as possible.   

 

Optimal Vertical Tracking Angle (or optimal SRA) is determined by measuring the Intermodulation Distortion level (IMD%), optimal VTA/SRA is achieved when both Left and Right channel displays the lowest level of IMD%.