Fozgometer V2


I've been interested in a fozgometer for some time now. I'd like one to help me understand crosstalk and channel separation, so I've been aiming to pick one up. Stopped by a dealer today, was told they're essentially "for people who want to waste money" and "why would you need one of those when you can put on a modern pop mono record" to measure Azimuth. I was told this tool isn't any more more correct or exacting than your ears, but they've never used a Fozgometer (even though they have access to them. I've tried this particular dealer multiple times and just always seem to leave with a bad taste in my mouth and always ask myself why I torture myself with even visiting them.

What are some general thoughts on the Fozgometer V1 or even V2? I don't own an oscilloscope nor do a have local hifi enthusiasts to help educate me. My current setup for cartridge alignment is the mirrored version that's available for $15. I'm looking to get more precision out of my alignment and figured the Fozgometer was a tool to not only measure, but to corroborate what I'm hearing. Any advice?

128x128j-wall

Do a search on these threads, on the subject of "Fozgometer" or "Azimuth".  You will find out about the good and the bad.  It's a controversial tool, to say the least.  I don't know whether version 2 is any different from or better than version 1. And then also seek out the paper by Korf on azimuth adjustment, on line.

In the latest edition of Stereophile Fremer reviews the updated version.  He concludes that it is a useful tool that gives results equal to using an oscilloscope, but easier.

j-wall

What are some general thoughts on the Fozgometer V1 or even V2? I don't own an oscilloscope nor do a have local hifi enthusiasts to help educate me.

You can use your PC as an oscilloscope along with something like the Hantek 6004.

@lewm have you used the Fozgometer? Do you have any opinion on it? I did some searching and found a few things, but they were very old threads, so I wasn't sure if the information was still relevant. I'm open to other options as well. I just want to have high accuracy and understand the relationship from good enough to as close to perfect as possible. 

@onhwy61 thanks I just got my copy last week. I've been checking the analog planet website once a week for a few months waiting for him to release the article. 

@cleeds  I'll check into this thank you. 

j-wall, No, I have never used a Fozgometer.  But I have formed some impressions by reading the several discussions of it here.  For one thing, it seems odd to me that many report it does not work correctly unless you have "fresh" batteries.  The typical 9V battery is fairly robust and maintains a minimum of 9V for a long time, given a reasonable current draw.  Fresh ones right out of the container typically measure 9.2V to 9.4V in fact. So, why does the Foz go off with even slightly used batteries?  Maybe it draws too much current.  Second, based on the instructions for its use, I gather it works to equalize crosstalk, so that L leakage into R and R leakage into L values are equal, in other words.  There is nothing per se wrong with that, but in my direct experience adjusting azimuth by electrical methods (using a Signet Cartridge Analyzer and Shure test LP), you get better crosstalk numbers by seeking a setting that minimizes crosstalk on each side, without regard for whether the crosstalk db are equal to each other in both directions.  Moreover, sometimes when I have sought to equalize crosstalk, the cartridge has ended up so obviously askew with respect to the 90 degree azimuth setting that I feared damage to the suspension, cantilever, and stylus, not to mention to LPs.  Then more recently I read the articles by Korf on azimuth setting, and those convinced me that the best compromise is to set the stylus tip so it sits squarely in the groove, by visual inspection, and accept that the electronic result may or may not be perfect.  I no longer attempt to set azimuth electronically (although I own all the test gear imaginable, save for a Foz, to do it).

I use the Fox 1 (same but uses batteries rather then plugged in).... Its made a very big difference for the better.....easy to use.....great results. Don’t forget the recommended LP for it.

@lewm thank you for the insight. I might pull the trigger to test the Fozgometer and get familiar with the experience of what is correct and what is close enough. I guess it's more of an expensive experiment to learn. 

 

@stringreen what did you notice about the Fozgometer that was missing without it? I'm looking for easy and a tool to allow me to set and forget, but also learn some things about azimuth and using tools for accuracy. 

We have two separate questions, the value of setting azimuth accurately, and the value of a Foz  to attain that goal. I don’t think anyone would argue it is not a good idea to set azimuth as close as possible to correct, wherever that is. And by whatever method.

Sound card on a computer, with a line level input from a phono preamp or integrated with phono and a preamp output (for adjusting the input level to the sound card), some free measurement software -- and Robert will be as a near relative of yours.

Teo, by your method you’re adjusting for cartridge plus phono plus linestage, not for the cartridge alone. Not that there’s necessarily anything wrong with that. I had a real Uncle Bob, so Bob was always my uncle.

@lewm why would you not want as close to balanced/correct as possible? Isn’t channel balance and accuracy the ideal goal of using a tool? This dealer also mentioned there is no "correct azimuth", but wouldn't as close to complete balance be ideal? And doesn't a tool provide more accuracy than "I trust my ears and tools provide no value"?

For the sake of preserving the record and reducing stylus wear, I prioritize having the stylus as close to perpendicular to the record surface as possible (optical setting using magnification), and using the Fozgometer to make any minor adjustment that improves electrical performance.  Fortunately for me, it was an incredibly small adjustment that did not even register optically.  Absent a meter, I would stick with the optical approach, and employ minor tweaking by listening if that effects an improvement in the sound.  

@larryi do you have any recommendations for tools you use? It seems as if the Fozgometer may be a beneficial tool, but might not be a starting point and rather an ending point. 

j-wall, Adjusting for azimuth has very little effect on "channel balance" per se. It only affects crosstalk and the fact that it affects crosstalk is the only reason to obsess over it. So, don’t conflate "channel balance" with setting azimuth so that crosstalk is equal on both sides. I say this with conviction, because not only have I read it but also I have personally confirmed the minimal effect of azimuth on channel balance, using my Signet Cartridge Analyzer and an appropriate Shure test LP. Very extremes of azimuth angle in either direction had at most a 1-2db effect on channel balance, as defined by the signal voltage in channel R as compared to the signal voltage in channel L (not crosstalk). Furthermore, you would never want to play records at any of those extreme settings, because doing so would damage the cartridge and the LPs.

I can see why you might have been confused by what I wrote earlier, but I tried to be clear I was talking about crosstalk; some like to set crosstalk equal, so that leakage of R channel signal into the L channel is equal to the leakage of L channel signal into the R channel, in db. In my experience, when you set that goal, you have to sacrifice to some degree the level of channel separation you potentially could otherwise achieve, which is to say that the absolute value of crosstalk you can get to is greatest if you just shoot for minimum crosstalk, regardless of whether the numbers are equal. To illustrate, maybe you can achieve 25db of separation on both sides (the signal voltage applied to the R channel that leaks into the L channel is down by 25db vs what appears in the R channel and vice-versa) , but if you just adjust for best values in each direction separately, you might achieve -30db on one side and -27db on the other. I’ve read arguments for either end point, but I think the Foz is designed to achieve equal crosstalk. So also, all of this is about setting azimuth electrically. Korf and others have made a good case for setting azimuth so the stylus sits squarely in the groove, without regard for the numbers game. You could call that the mechanical method. It requires some degree of faith in cartridge manufacturers, but at least you know you are not wearing out your stylus aberrantly (by having it at an angle to the groove walls) and that you are not damaging LPs. I have moved over to that side of the argument; I no longer use electronics to set azimuth. See also what Larry wrote above.

@lewm this is what I needed to hear. Thank you for spending the time. So essentially, I should be wasting my time focusing on other factors such as VTA and Maybe fiddling with a Wally Tractor? I might have possibly skipped a few steps in the learning curve looking at a new gadget. 

I use a Wallytractor to do the basic alignment and I use a 10x magnifier to see the markings.  The Wally Tractor is not the easiest tool to use, but it gives you more ways to confirm your alignment is good than other protractors and it is the best thing to use for my Vector arm which is a little bit hard to locate the precise center of the pivot.  I also have a SmarTractor (donated to my local dealer) which is far easier to use and I highly recommend it where the pivot point is easy to find.

I use a mirror of the right thickness and the magnifier to confirm proper optical azimuth setting.

VTA/SRA I set by first establishing thar the arm is parallel to the record surface (a ruled index card set just behind the arm makes this easy.  From there, I just experiment by listening.  If the pivot is raised too high, the sound is thin and sibilant, too low and it sounds dull. 
I have a USB microscope, but I never use it for alignment because it is a pretty fussy thing to set up and aim properly.

@larryi awesome stuff. I've been checking out the Wally gear and Dr Feickert protector as well. I guess I'll start here and see where it takes me. 

My understanding is that the Foz (V1 and V2) uses channel balance and channel separation/crosstalk to set azimuth, but does not take into account phase angle to set azimuth. The Foz assumes the best channel separation/crosstalk will be at the same point where there is zero phase angle, which is what it should be in theory but, given manufacuting variability, is not always the case in actuality. But the Foz is better than some.of the other ways of adjusting for azimuth.