damn, I have always done this by ear. Guess I need to blow $250...
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If you have a record with left channel only tones and right channel only tones you can record these with something like Audacity and adjust azimuth until you reduce crosstalk (relative level of the "silent" vs. non-silent channel for left and right) as much as possible. Obviously a more tedious procedure than having a gizmo like the Fosgometer, especially on my SME 309 where the azimuth adjustment is achieved by twisting the replaceable headshell.
Yet another audiophile discovers that the mirror can lie. Is that a new wrinkle?
But seriously, if you paid the dough for a Triplanar or the like, you are cheating yourself if you don't also set azimuth electronically, at least initially. THEN you can fine tune by ear. Good to know tha the Foz works.
damn, I have always done this by ear. Guess I need to blow $250...John, I'm surprised you weren't their first customer!! ;--))
Unfortunately (fortunately?) my SME V doesn't allow for such tweaking, so I have to rely on the skill of my cartridge maker. However, the Cardas test record has a white noise track where the L and R channels are 180 deg. out of phase to each other. If your preamp has a "mono" switch, activating it will combine the channels resulting in cancellation -- and when the azimuth is "right on", almost no sound will come out of the speakers. If you use headphones, or a digital VU or voltmeter to do the test (instead of your speakers) you will have no trouble adjusting the azimuth for maximum channel-to-channel cancellation. And you can "high five" yourself for saving $250.
I've regularly been able to reproduce the minimal crosstalk position (as measured by a Wally Analog shop) when adjusting by ear (and yes, the final adjustments are VERY small). The Fozgometer is faster, easier to use and less expensive than Wally's device, but unless it's more accurate it wouldn't seem to offer much value for me.
It would be fun to play with, but I personally wouldn't drop $250 just for that. YMMV of course...
I agree with Doug. Someone once told me in my Shure cartridge days (when we eyeballed everything!) that unless the cartridge was obviously "tilted" ;--) it would be "just fine". So for me, everything was "just fine" for many years.
John, the track I use on the Cardas record is No. 3 on Side 2. It's actually 32 concentric (independent) grooves, so you can drop the stylus into any one of them and it will provide a continuous signal of out-of-phase white noise. If you can set your preamp to "mono", you can take a signal out of one (either L or R) of the main outs starting with the main volume at minimum until you find the best meter range setting (unfortunately the tape outs on most preamps will remain in stereo even when the preamp is set to mono ;--) Then you adjust the azimuth for the lowest meter reading. If yur preamp doesn't have a mono setting, then you can put a 'Y' connector on either the main outs or the tape outs and hook the meter to the 'combined' leg of the 'Y'.
the only problem with the whole 'minimal crosstalk' approach (which i have used) is that it's only close to optimal. i have found that i can eyeball azimuth typically as close as when i measure minimal crosstalk.
dead on azimuth is where the phase is aligned, not gain. the image snaps in based on phase being equal in each channel.
i suppose that the Fozgometer must somehow measure phase.
i have the new Talea tonearm with dynamically adjustable azimuth. i know of no other arm which allows one to adjust azimuth while listening. i watched the arm designer use this to dial in azimuth and it really works.
I agree with Mike, that phase is everything in azimuth adjustment -- however, from my reading of the Fozgometer instruction manual:
it only measures L or R crosstalk levels (separately of course which is good) and L vs. R cartridge output levels (balance) AS MEASURED THRU YOUR PHONO PRE. I mention that little detail here because that fact makes it important to know if your phono pre is in perfect balance first! Now, that's easy enough to find out by running JUST the left OR right tonearm lead/signal thru one and then the other channel of the phono pre and making sure the output of each side (measured thru the tape output on your preamp) is the same. The Foz can balance the signal for you internally which is nice; otherwise, if any of the cartridge, the record, and/or the phono pre are not each in perfect balance, that CAN be adjusted with the preamp's balance control, EXCEPT you'll then have to take your readings from the preamp's main outputs, not the tape outputs. Just remember, results with the Foz or any measurement device depend on/assume the L and R signal are the same strength, whether your testing is crosstalk-based or phase cancellation-based.
It's recommended the Foz also be used with a test record -- one with which I am unfamiliar, so I don't know if it contains an out-of-phase mono track. The Cardas record does, and it was cut by Stan Ricker, the best in the business, so I would rely on its accuracy: i.e. that both channels are precisely cut at the same amplitude, AND that there is a minimum of left/right phase cancelling crosstalk in the grooves themselves.
Both measurement techniques -- crosstalk levels or degree of phase cancellation -- will provide dependable result if set up and carried out with good experimental technique ;--) however I prefer the phase cancellation method because I feel it's more precise (i.e. the cancellation is either complete, or it's not) while the crosstalk method involves some subjective judgement (as implied in the Foz manual.)
Yes, you can use an oscilloscope as your measuring device; and if you're measuring crosstalk, it's essential if you don't have a Foz. But if you have a Cardas (or other) test record with a L/R out-of-phase track, and a mono switch on your preamp, then any device (including your ears!) will do just fine ;--))
...dead on azimuth is where the phase is aligned, not gain. the image snaps in based on phase being equal in each channel.Now that you mention it Mike, this makes more sense than merely minimizing crosstalk.
Reducing stereo crosstalk certainly helps a binaural listener estimate the size and direction of a mock-single sound source coming from two speakers. But the image will only "snap into focus" when phases are precisely in synch AT THE LISTENING POSITION.
Given the effects of room interactions, which Fozgometer, Wally and oscilloscopes cannot hear, one could argue that final adjustment by listening is THE most accurate method for musical listening purposes.
For me as for you, setting azimuth is a simple, two-stage process:
1. make the stylus look vertical by eye (resting on a mirror helps)
2. fine tune until the image snaps in (this can be done listening to music if you don't enjoy test tones)
Measuring devices just over-complicate this straightforward, though vital, adjustment.
Agree the Talea's on-the-fly azimuth function makes it very easy. I've played with it for visual azimuth but didn't have time to fine tune aurally during my too-brief audition of that exceptional tonearm.
Dear Mike, Did you set your azimuth using the Feickert stuff? I ask, because I have seen that done, and phase-matching is used as a criterion for the optimal setting. However, at the risk of sounding like a curmudgeon, I would point out that music (or anything besides a pure sine wave test tone) is a complex mixture of many, many frequencies, each of which will have its own phase characteristic. It would be impossible to match them all truly between R and L channels (except possibly with state of the art digital intervention, which we don't want). So we have to settle for some average setting that makes the brain most happy. Then too, there are the unpredictable vicissitudes of one's room reflections, speaker crossover, speaker drivers, etc, to alter phase again, even the phase angles for each frequency were to emerge perfectly matched from the phono stage. But I do take the point that there may be some setting which is found to be most pleasing due to its average effect on all frequencies.
Joel Durand, of Talea Tonearms, set up my Talea in my room. he used an Ella Fitzgerald mono Lp to make the dynamic adjustments to the azimuth. i can tell you that it took our 'eyeball' azimuth set-up to another level.
The Fozgometer measures crosstalk and channel levels through a filter. It's a good start but by no means is the optimum way to set azimuth. Feickert uses the transfer function to measure phase response, to which the ear is much more sensitive. Minimum phase error between channels is often in the ballpark of minimum crosstalk in terms of azimuth angles but rarely coincides.
For far less than $250 you can get someone to do the full Feickert alignment service.
regarding the Fieckert software; Michael Fremer has done a seminar with Dr. Feickert at RMAF the last 2 years that i have attended. he showed graphs of how this software shows how the best crosstalk position compares with the best phase angle position with azimuth. it would be a coincidence if they happened to be the same.
info on Feickert software
I printed out the manual for the Fozgometer (thanks Nsgarch) after a bit of figuring to keep the pages in proper sequence -- first page blank on back side, then remaining pages back to back for 2/3 and 4/5.
It all seems pretty simple but I have a question about the inclusion to measure channel balance -- what is the value of that? Once you've gone through the procedure to set azimuth you're not going to change anything to adjust balance.
I can see where this would tell you if your aggregate balance of cartridge and phono stage was correct or not, but you can do that with a multi-meter. So, is there another purpose I'm not thinking of?
This is just a stab at the question: To set azimuth with my Signet, you first have to set the meter to 0 db for the channel that directly receives the signal from the test LP, so you can then measure the crosstalk in the opposite channel. When you do that in both directions, you have to have balanced the signal each time in that way in order to compare the crosstalk numbers (which are in terms of negative db, down from the 0 db reference). Perhaps that is what is going on with the Foz.
I admit I'm not as versed on these issues as you all seem to be. Having said that, here are a few remarks...
Adjusting azimuth by eye... That seems to be the preferred and less expensive method. My issue is, why is so much written about proper cartridge, tonearm, TT adjustment and their importance, but somehow azimuth adjustment is OK by eye? Just recently MF from Stereophile had a comprehensive article on STA, (stylus rake angle) and just 2 degrees off of the standard 90 degrees makes all the difference in the world. So my point is, if this is true, should we just use our eyes for azimuth as definative setup tool. As my system has gotten more resolute through the years, any "slight" changes are extremely more noticable. Therefore, why is it not acceptable to use a $250.00 device that will take one often thought about equation out of mind, so as to explore other issues?
Isn't it better to be able to rule out one importantant aspect of cartridge allignment so other sensitive issues can be addressed? Example: Tom Port tried to get me to not spend "big bucks :on a VTF meter, saying you can do it by ear. Well, yeah!. But who wants to start at a far off place only to find later that their search could have been made so much easier with a quality scale?
If you want to be Daniel Boone, go ahead, My time is impotant to me and worth a lot of money.
II'd rather spend the bucks on a quality device that will get me in the right direction. This will also allow me to check any variations I migjht suspect rather than fretting over what might be!
I for one would not quibble over the price of the Foz. I was trying to find out from owners how it works is all, so I could decide for myself whether it works as I would like it to do. I want my $250-instrument to take me where I want to go. Setting by eye would be OK, if you knew for sure that the transducing mechanism inside the cartridge body was completely squared away with respect to itself and to the cartridge body.
Setting VTF by ear could get one in a lot of trouble. Obviously you need to have a known measured starting point else you may crush your cantilever or damage an LP.
Dan: Nice! The Talea is a unique tone arm. It would be great if more tone arm designers and manufacturers began treating arm height and azimuth adjustments with the same importance as they do tracking force (counterweight) adjustments. With so many tone arms, arm height and/or azimuth adjustments are either lacking entirely or crudely implemented. On-the-fly adjustments may not be a priority but at least they should be easy and fairly quick adjustments.
I still think the Fozgometer offers a good starting point (an easily repeatable reference) for fine-tuning azimuth adjustment, even for tone arms like the Talea.
I don't quite understand your post, Dan. It would seem that if you own a Talea or any other tonearm with easy, accurate, and repeatable azimuth adjustment (Triplanar, Reed), then the usefulness of a device that provides an electronic method for setting azimuth is all the more merited. This is not to say that the Foz is the one and only good choice for this purpose. Once you get it electrically "right", you can fine tune by ear. IOW, I agree with the last sentence of Tom's post, in essence, altho I'm still in the dark re the Foz per se.
I ordered one from Acoustic Sounds and I had it in five days (at cheapest postal rates).
It took less than 10 minutes to fine tune azimuth with this meter (very stable, unequivocal readings). Unlike the Wally instrument, the readings held steady. Also, unlike the Wally instrument, I did not have to deal with making conversions to db to do a left minus right, right minus left calculation. My adjustment from visual, perpendicular alignment was extremely small (I cannot reliably see the difference). In other words, it is a very sensitive instrument that shows the result of VERY small adjustments.
Of course, it is minimizing crosstalk at only one test frequency (1 kz on the Analogue Productions test lp), unless one finds other test lps with single channel signals at other frequencies.
After browsing the Feikert instructions, I realize that I require a no-brainer" device like the Fozgometer. It is now making the rounds of my friends.
Of course, it is minimizing crosstalk at only one test frequency (1 kz on the Analogue Productions test lp), unless one finds other test lps with single channel signals at other frequencies.Two reasons in one sentence why some of us will probably never buy it.
First, 1kHz is well below the optimal frequencies for setting azimuth.
Second, as Mike Lavigne and others have repeatedly explained, minimizing crosstalk provides only an approximation. One must still tweak from there to minimize inter-channel phase discrepancies. He, Dan and I do this by ear. So can anyone, with practice. The Foz doesn't do it at all.
For $250 the Foz quickly and reliably gets one in the ballpark. However, as Larryi also discovered, making the stylus visibly vertical also gets one in the ballpark, so close that "adjustment from visual, perpendicular alignment was extremely small (I cannot reliably see the difference)." How much more in the ballpark need one get than that? Why spend serious money to just to get in the ballpark? I can get there for free in seconds using the loupe and Mint protractor I already own.
As Dan suggests, azimuth is easily and accurately adjusted in two simple steps:
1) make the the stylus vertical by eye;
2) fine tune in TINY increments by ear.
The Talea makes executing step 2 much faster, but it can be done by ear on any arm with adjustable azimuth.
100% what Doug said. Getting AZ correct by listening can be problematic for even seasoned listeners when using an arm that requires the adjuster to start and stop while actually changing the AZ. This can make it very easy to lose the reference that was just heard prior to stopping to make the change. For this reason I would use my DMM to crudely minimize crosstalk with my Triplanar one time, then adjust by ear from there.
Palasr and I played with the OTF azimuth on the Talea proto at his place. I would describe the change by recalling to everyone the Bose radio commercials where the picture of that tiny system suddenly grows to some enormous size. That is how I would describe the change in sound when the AZ is dialed in and out on the Talea. You can easily hear the fullness of sound come in and out. It takes very small turns on the AZ adjust screw of the Talea.
I have nothing against the Foz, I just don't need it or Feikert's software with the Talea. Heck, I don't even need my DMM anymore, not that it was all that helpful. :-)
I have the Fozgometer. It's a great tool and I recommend it. It seems like this tool still just isn't enough for some, because of the tone used to test at etc. But, put it in perspective: EVERY adjustment on a turntable is an approximation. Alignment is an approximation (pivoted arms), VTF (subjective for sound), VTA/SRA (no standard), and now azimuth. So really, theres no such thing as an absolute setting for any of this. The Fozgometer is reliable and the simplest way to get azimuth as close to ideal as possible.
I believe the way this is done "manually" is to convert millivolts to db, then you would do a left minus right and right minus left calculation to determine crosstalk. A straight reading of channel output would not account for channel imbalance. Also, it is possible that the Fozgometer does more than just measure voltage output (e.g., it could include filters to attenuate frequencies outside of the 1khz test signal so that the effect of extraneous surface noise is reduced. I don't know if this has actually been incorporated in the design, but, I do note that the needle does not jump around a lot whereas readings done with a VOM are more equivocal. I also don't know if the Fozgometer does or does not incorporate some kind of analysis of phase relationships (aside from doing the L-R and R-L), but that is possible since Fosgate is an expert in that field (one of the pioneers of early SQ matrix form of four channel sound).
Capnbob, As Larry inferred. There is no doubt that one could do the measurements done by the Foz "manually" with a proper test LP, a fine quality voltmeter, and/or a 'scope. The Foz is a matter of convenience and rapidity, plus you can be uninformed and still get it right, electrically at least. Also, good 'scopes and meters are not exactly cheap. Nor are the brains to use them correctly common among us audiofools. My only questions about the Foz are like those stated by Larry; I really would like to know exactly how it arrives at its "correct" azimuth setting, because there is more than one opinion on the definition of correct azimuth, even in the electrical sense.
I used Mac The Scope software before I used the Fozgometer. The results were identical. However, the Fozgometer appears to use a filter because the needle read out is very steady. It's also extremely sensitive to the slightest azimuth adjustment (duh) and can take the signal directly from the tonearm (no need to go through the phono stage). I have a low output MC cart and it gave plenty of signal. Easy-peezy, and looking at high magnification, it's perfectly straight.
If with Fosgate, all you are doing is balancing the crosstalk between L and R, then I think it is not worth it.
You need to take into account the difference in output between L and R on a cartridge.
I setup a Grado The Statement by eye (which is the way John Grado recommended along with a tip to stay away from test gear and test records) and then measured with Adjust+ Pro. The reading showed the same exact phase angle and crosstalk difference of less than 0.5 db between L and R. So in this case, both the eye and test gear method worked quite well.
In the included manual for the Fozgometer this is whats said about its way of determining azimuth.
The Fozgometer represents a breakthrough for adjusting phono azimuth. The Fozgometer incorporates a "Log Ratio Detector" developed for surround processor steering logic circuits to measure channel separation over a wide range of signal levels down to -70db. The readings are virtually independent of overall signal levels, and can be made with a wide range of input signals without effecting accuracy. It is a small portable battery powered unit that is used in conjunction with a test record. It measures channel separation, channel balance, and signal direction quickly and accurately.
I borrowed a friends and just because of its ease and ability to get you so close to right on i bought one for myself. I understand about the hands on of vinyl playback and its one of the things i love. In the case of the Fozgometer the time saved is a valuable thing for me as i can spend more time in the listening chair instead of up and down to the back room for adjustments. I believe this tool should be right there with your wally tracker and digital scale.