I think you have to ask VAC what is the sensitivity of those LEDs to signal voltage. At that point you would only know that your crosstalk is less than the minimum value needed to light up the LED, because the LED is "off", but it won't tell you by how much you're under the minimum signal voltage.
You have to measure the signal voltage in each channel and then calculate crosstalk in db, in order to be able to think about your set-up as compared to some optimum. Typically, a very good well set up cartridge will have the non-driven channel at around -30db with respect to the driven channel, R into L and L into R, at a midband frequency, like 1kHz typically. I think the short answer to your question is "yes and no". It also depends upon your own tolerance for exactitude. How accurate do you want to be? |
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Thanks for the insights.
I have been thinking about getting a Foz. I also have a 3d arm on order so I want to make sure I do this right. |
The 3D requires the best setup possible...the arm is THAT good. The arm will sound great, but a slight adjustment of this or that, can really be heard. Don't think about it ..just get it. |
Thanks again. Your review of the 3d arm is what motivated me to take the plunge so I will definitely take your advice on the Foz. |
Love my Foz. Check out Michael Fremer's recent blog on Analogplanet re calibrating the Foz. |
Yes. I saw Mickey's article. Looks like calibration is a must.
Anyway, I put my order in and should be receiving my Foz shortly. Not sure when I'll receive my 3d arm though. Still haven't received confirmation from VPI that they got my order. Seems like they're real busy these days. |
..just some things to add about the Foz. Be absolutely sure you are using a brand new battery. Old batteries may seem to work, but are best tossed. Sometimes the meter doesn't work. If that's the case, the meter has very long extensions on it that may be touching the case from within. Either tape the case or the meter connections. Enjoy. |
I don't want to throw cold water on the Foz, but after reading the articles about the need to calibrate it and then noting that calibration is not exactly a simple matter, I am even more prone to stay away from it. Its accuracy depends upon the stability of the voltage from a 9V battery. First of all, I can say from having measured a number of new 9V batteries that the baseline "9V" is an approximation at best. They tend to deliver slightly more than 9V when new. Some can be at 9.2V, some at 9.4V, etc. From what I was able to glean, those tenths of a volt differences can affect calibration of the Foz. (One guy who responded to Fremer's blog noted that his Foz told him to tilt his cartridge by 15 degrees to obtain optimum crosstalk!!! Either his cartridge is grossly faulty or the Foz is way off, and odds are it's the latter.) So, it is a given that you need to calibrate every time you replace the batteries. Then there is the issue of the effect on calibration of voltage drift or corrosion on contacts or etc. I'd like it better if the battery fed a voltage regulator, but that might result in a prohibitive size for the Foz. Another option might be an outboard PS that plugs into the wall to power the Foz and delivers a well regulated constant 9VDC to it. That way, you calibrate once or at the factory, and forget it. I was surprised that Fremer documented so well the need for frequent calibration and then went on to confirm his strong endorsement. True, there is not much competition. |
I have noticed that some arms need to have the ground wire connected to get an accurate reading, others don't. Perhaps the guy with the 15 degree error had his ground disconnected. |
The better way to go is the Feikert Adjust program. I have used the Fozgometer and I now own the Feikert. Besides being much more reliable it is much more accurate. Add to that it can be used to check speed and frequency response, for just a few dollars more.
This of course, just my opinion. |
Lewm, whenever someone recommends the Fozgometer...
You seem to have a bucket of ice water at the ready. Keep up the good work, helping to protect gullible (or incompetent) audiophiles from getting ripped off. :-)
I hate to deflect your cold water, but if the Fozgometer was that bad I would expect to see a bunch of them for sale at discount prices. But you seldom find used Foz's for sale on eBay or Amazon or the many forum buy/sell websites. (I suspect that as the vinyl bubble subsides we'll be seeing more of them. But I also expect to see a bunch of turntables, cartridges, phono stages, RCMs, setup tools, and records for sale as well.)
That aside, Mr. Fremer said he got the same results with the Fozgometer as with the digital oscilloscope. That's good. No?
Regards,
Tom |
Enough people buy Fozgometer for ease of use.
Many voltmeter with notch filter can serve the same purpose.
I use a Phonic PAA3 meter which has many more functions for not mch more money. |
+1 for the Foz. The calibration procedure takes about 2 minutes - most of that reading the directions. No more complicated than biasing your tubes. I still check mine out every few months when rechecking the turntable geometry, but it has not changed in more then a year - since I started keeping it in a location where it doesn't get jiggled around much. Use it a few times and the whole process will take less than 5 minutes, including mounting the test record. There probably are better azimuth tools out there, but none as easy to use. This is one of those rare audio gadgets that is actually an over-achiever. The calibration procedure is actually balancing the readings for both channels with a constant signal by using a small screwdriver until the meter indicates the same value for both channels. If the calibration step is not performed it is quite possible for one channel to be off enough to skew the result by a large margin, but common sense should dictate a point where one visually sees the madness in believing the instrument and reading the one-page manual to discover the fix. |
Tketcham, I too noticed that I might appear to be conducting some sort of vendetta against the Foz. Believe me, that is not the case. I have been moved to comment several times, it's true, mostly in response to the comments of some who actually own the thing. It's often difficult to tell whether the user does not understand how to use the Foz or whether the fault(s) lie in the device itself. I tend to think it's more the former than the latter, but that implies that the Foz needs a better more explicit instruction manual, at least. This latest business about precise battery voltage also stirred me up, I must admit. I will maintain radio silence from here on, I promise. I actually have high regard for the Fosgate company and Fosgate the person. |
Lew,
Regarding the guy who was invited by the Foz to tilt his cart by 15 degrees? I thought that the Foz was looking for the lowest individual value per channel but this suggests that it was trying to balance/equalise crosstalk???
It would actually be helpful if Mr Fosgate or his designate could make a guest appearance, like many others, and clarify some of the issues raised? Might take the heat out of discussions like this ;^)
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So to revive an old thread......I use a downloaded o-scope with the Analogue Test Record. I play Track 1, 1kHz tone in each channel, then switch back and forth between L and R on the o-scope and make adjustments to get as close to same reading as possible.
It reads mV and I get output something like X.XXXX the last 3 digits is what I try to make as close to same as possible.
Does this make sense? I used to set AZ by sight using the mirror method and magnifying glass. The very first time I used the o-scope the results were impressive. |
