I think the DaVinci head shell is machined dead flat and with the pivot point being contained in its jewelled double gimbal bearing, it ain't moving anywhere out of alignment.
The problem is of course, that not all cartridge bodies are as perfectly flat nor are the cantilevers for the stylus assembly perfectly aligned and rarely are the styli themselves mounted in perfectly vertical alignment to their cantilevers.
This seems in practice to put most cartridges I mount in my DaVinci 12" Grandezza Ref 'out' of perfect azimuth alignment.
I compensate (as you suggest), with the 'balance' control on the pre-amp.
Not ideal for the 'purists' out there but in the real world of sound, it's hard to find an arm to beat the DaVinci IMHO. |
Never had that problem, but I would send it back for repair. |
Agree with Syntax. If it's truly the arm that's out and not the cartridge, get it fixed. If it's visible to you, it was visible to the builder. IMO there's no reason to accept clearly visible inaccuracies at this price point. You can get those on a Rega.
Azimuth affects more than L/R channel balance. That isn't even the main thing it affects. As good as the DaVinci arms are, the lack of adjustable azimuth would be an annoyance for me. But Halcro already knows I'm one o' them purists! ;-)
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Dear Halcro, you can not compensate azimuth offset with balance control. Azimuth offset means - always! - a misalignment of the stylus towards BOTH groove walls. This has to be fixed at the source. You can mask the sonic result to some degree (in fact only the channel imbalance.. ) with the balance control, but the problem remains and it will shorten both - the life-time of your stylus AND records.
Aside from the sonic presentation (soundstage width and depth and high frequency reproduction) which does suffer too.
To fix this issue, do get AND use very thin plastic washers (sometimes part of cartridge screws by-pack assembly) to eliminate the problem where it occurs.
Greetings to sunny Australia - its 6 degrees below zero here at my place....
D. |
Psag,
With the azimuth off, is one side louder than the other, or is the soundstage shifted to one side?
rgds
alec |
Alectiong,
Since Psag hasn't adjusted his azimuth he may not be able to identify what effects it has.
Azimuth inaccuracy has all the effects Dertonarm described and it also has a major influence on L-to-R image focus. I used to take electronic crosstalk measurements to adjust azimuth. With practice, I've learned to adjust just as accurately by listening. Image focus (tight vs. fat) changes more than the soundstage shifts, at least IME.
Optimal adjustment needs to be much finer than is possible with headshell shims, but if that's all your arm allows AND it's visibly off, they're certainly better than nothing.
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Hi Pasg,
having read all the previous inputs I suspect the mounting base is not level with the platter or the pivot post not 90 deg. relative to the plater level. This would cause an azimuth off-set from the arm post relative to the platter...
If this (for what ever reason) is the case, it can be checked with a small level on top of the head-shell. It could possibly corrected --- at the source of the trouble.
Note: IF the arm post is correct (90 deg. with the platter) the azimuth deviation ought to be of the same off-set at the start, middle and end of the record. ALSO, this measurement is ONLY correct if the head-shell is very close or at the level position where the stylus contacts the record!
In the case of my SME V arm with SME 10 tt, I had to shim the arm mounting by ~ 0.2 mm to correct for such a deviation.
In this case it is an issue with the arm's pivot-post somehow not aligning a proper 90 deg. to the mounting base, (which in my case is level relative to the platter)
Yet, playing with out the shim, I can not detect any shift in imaging or one side louder then the other, it is not enough of a deviation (I think). However, when corrected there is less miss-tracking, OR groove distortion with very critical tracks :-)
Axel |
I don't have this problem with my first generation Da Vinci Grandezza arm and the Clearaudio Harmony Mg.
For what it is worth, and I don't vouch for its accuracy, Soundscape Hi Fi in Singapore state the following about the Grandezza arm:
"Double gimballed ruby bearing, no need for azimuth adjustments"
link: soundscapehifi.com/da-vinci-grandezza-grand.htm |
I would add anything Soundscape Hi Fi said with a grain of sald after spending an hour talking to him in the store. |
Hi Daniel,
Only 6 degrees below??........that MUST be global warming!
Here in Sydney, after a hot Spring, we are having a cool start to Summer.
Of course Doug and Daniel are correct and perfect azimuth is great to achieve.
I have never had a visual discrepancy of 'several degrees' with the DaVinci and the effect is simply manifested in a 1-1.5 dB attenuation in the right channel of my speaker which I accommodate with the balance control.
Having said that, it may simply be my preamp at fault because the correction seems to suit ALL my cartridges and all my other arms?
In other words.....ignore my previous comments and check your DaVinci as other posters suggest. |
Psag,
Another thought occurred to me.
The DaVinci VTA Tower is elevated by a threaded rod operated from the top of the pivot housing.
Once you are happy with the VTA alignment, you must lock the base clamp in and then RETRACT the adjustable threaded rod so that it is no longer bearing on the base plate. In other words, the VTA Tower is held solely by the base clamp and NOT also resting on the elevating rod.
If you still have a problem with the level of the headshell after this, Peter Brem and Jolanda will certainly help you. |
I agree that on an arm at this cost should be built correctly.
Having the headshell level, though, gives absolutely no assurance of optimum azimuth setting. Getting it properly aligned is a must. |
Hi all,
as I mentioned in another thread just now, in the case of the SME V the locking of the arm-post in the case of the V allows for some 1-2 deg. tilt relative to the mounting surface. If I read Halcro's comment with the VTA lifter = threaded rod, I think immediately of the same being the case with the SME V.
In fact I have given up using this "tool" altogether and now use a number of shims made of hard wood --- which also is a bit more "repeatability" then some threaded rod that happens to push the arm post *always* to the opposite side of the where the threaded rod is located.
Ladies and Gentlemen ---- so much for azimuth precision!
Guess why Graham's Phantom II has now an added, permanent "spirit bubble" to his latest creation...
Greetings,
Axel |
Thanks for all your helpful responses. I checked the base and then the headshell with a bubble level, and there is a discrepancy between the two. Halcro, Peter and Jolanda just sent me a helpful email with exactly that suggestion, which I will try tonight. |
I suspect that a shim between the armboard and the arm collar will provide a good solution. I'll be back. |
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Guess why Graham's Phantom II has now an added, permanent "spirit bubble" to his latest creation... Good question, Axel. I can't imagine anything less useful (except maybe a Wally Skater). As Essentialaudio said, getting a headshell level is no guarantee of proper azimuth. It's not even the best visual starting point. Balancing toothpicks on headshells a la VPI or futzing with a Phantom bubble is focusing on the wrong parameter. Assuming the arm isn't flawed, as Psag's appears to be, azimuth is about adjusting the stylus in the groove. That's where you should start - that's where you should finish. Nothing else matters. Given the multiple variabilities inherent in even the best cartridges, levelling a headshell is foolish. Spending money on a bubble to level a headshell is just foolishness squared. Perhaps the liquid provides some useful damping? ;-) |
Actually the Graham "level" does have some value, but not for azymuth, which is an axial tilt function. The true value is as a reference when jumping between different thicknesses of pressings. If you set the level for a 120g pressing and then adjust SRA from there you can determine the offest from zero. Then when you shift to a 180g (or 200g) pressing you can find your reference (level) and then dial in your offset. Guaranteed to have a constant SRA, no matter what thickness pressing you are playing. But, c'mon you knew that already! |
Has anybody here tried the Feickert software for adjusting azimuth?
Jeff |
Placing a shim between collar of armbase and armboard will create problems - and won't solve any. Correct azimuth is a must and is determined by the position of the stylus in the groove and towards both walls. Thus a headshell level (spirit bubble or not....) has little to no use as Dougdeacon and Essentialaudio already mentioned correctly.
The problem has to be fixed at the source - you can not "correct" a misalignment of azimuth anywhere else in the chain - only at the stylus.
If the stylus is not 100% vertical in relation to the upper plane of the mounting cartridge body, you need a headshell which can be rotated in its axis - at least to some degree.
Its an imperfect world - thus we need alignments.... |
Rsrex,
Good idea. Of course the optimal SRA for one 120g record is not necessarily the same as for the next, especially if it's on a different label. Ultimately each LP must have SRA individually fine tuned by ear. Still, starting from the same baseline for a given thickness should shorten the process - and of course you knew THAT. :-)
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If the stylus is not 100% vertical in relation to the upper plane of the mounting cartridge body, you need a headshell which can be rotated in its axis - at least to some degree. Or shim between the cartridge and headshell. I do that where azimuth adjustment is not available. A fraction of a degree can make all the difference. |
As for the Freickert-software... it implies for correct function in azimuth-adjustment mode, that both coils of a given cartridge do have 100% identical output.
If this is not the case - which you can count on in 99,99999 % of all cartridges - it will help you little to adjust azimuth. As it compares output of both channels to give identical readings.
You need to know the exact output of each coil before using this tool.
Hard to get......
Sorry folks - azimuth-adjustment in real world conditions has to be (and can only be ..) done by the one single instrument most audiophiles seems do trust the very least.
The ear........ |
Hi Doug,
if the arm-post is tilted relative to the platter (not 90 deg.), the azimuth keeps on changing from beginning to the end of the record, aye.
Why? Because the bearing (most usually has a ~ 20 deg. off-set relative to the straight axis of the arm). One thing I learned real fast when using some cheap arm (Pro-Ject 9c) with a sloppy arm collar for setting VTA.
Go figure... and Dertonarm should concede being in touch those Egyptian geometrists :-)
Axel |
Essentialaudio - agreed. That is at least a suitable option - if kind of archaic with tonearms asking $5k to $11k in retail price..... |
If the post is not vertical, I think the shim should go between the post collar and the armboard. However if the headshell is the problem, I think the shim should go between the headshell and the cartridge. |
Well, if the arm post is not vertical........ I would suggest changing either armboard, tonearm or hobby. |
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You're no less an audiophile if uncertain about your ability to detect single digit decibels of difference from vertical perfection. To confirm a setting or what you hear azimuth-wise, you can measure the differences in channel output with a voltmeter and test record. Check this thread: How to measure crosstalkOne place to find the Cardas test recordYou can compensate for channel differences in cartridge coil voltage output by getting a level set for each channel then adjust the output with your preamps L/R balance control. |
Post created for clarification only. I have no interest in debating how to set azimuth: As for the Freickert-software... it implies for correct function in azimuth-adjustment mode, that both coils of a given cartridge do have 100% identical output.
If this is not the case - which you can count on in 99,99999 % of all cartridges - it will help you little to adjust azimuth. As it compares output of both channels to give identical readings.
You need to know the exact output of each coil before using this tool.
Hard to get...... Not true. The software does not work this way. It uses a transfer function based on the output of the main channel relative to the crosstalk channel (20*log(Vx/Vy)). Your assumption of how the software works is incorrect. It does true azimuth calculations. If there is a 1.7 dB difference in channel balance the software does not care as it does not rely on matching channel balance. Dre |
Good post, Dre_j. Quite a bit of information about the Feickert software azimuth measurement, including the phase measurements as well, can be seen in the Azimuth compendium on his website. |
Andre,
This is interesting: does this function average over the frequency response, or does it work for specific frequencies set beforehand?
I've done experiments with a voltmeter (like many before me) to measure crosstalk and noticed that, for a given azimuth position, the crosstalk can be completely different depending on the frequency: for example, if the azimuth position was adjusted as well as possible at 1KHz by measuring crosstalk (same method as the one given above), it would be off at 100 Hz, and also off at 8KHz--in fact the measurements were opposite at those extreme frequencies... I've used my ears ever since....
Joel |
Well Dre, the transfer function gives only correct result relative to the azimuth (= correct position of the stylus towards the grooved wall for both channels) if factor x (here: output voltage) is known and thus for each channel.
Otherwise the calculation is always a relative one (which it is here).
Dear Jtimothya, to determine the correct output for each channel you do not use a test record. You need the pure output of the coil and the best way (and most precise) to obtain that basic figure is to get it WITHOUT a groove.
It works this way: get a Nagaoka or similar oscillating stylus cleaner. This gives a 400 hz or similar impulse on the cartridge - to both channels and independent of position of stylus. This has to be measured with a precise micro-ohm-meter.
You will get perfect and stylus position independent readings for the raw output of each coil.
Simple yet effective.
If we want a figure for factor x1 (coil output) and factor x in action is a function of factor y (position of stylus polished area towards grooved wall) or factor z (relative crosstalk to other channel - which here would mean x2....) - then I would look for a way to obtain factor x1 (and x2...) without other variables depending on.
Best of all .... - it works.
Cheers,
D. |
Dertonarm,
I believe I stated that I'm not going to debate setting azimuth. I clearly stated the software does not work the way you described and your subsequent post seems to acknowledge that your previous assumption about the software functionality was incorrect.
The point of my post was for clarification only.
Dre |
Joel,
I believe it is the later being frequency specific which is to our benefit. In practical application, it allows us to go beyond the loose standard of 1KHz if we choose to.
I apologize but my time online is short this morning.
Dre |
Dre, I am not discussing azimuth adjustment either.
As there is nothing to discuss in a simple geometrical issue like this.
And I clearly stated that the F. software does function in a way which gives a wrong result - at least regarding azimuth "adjustment".
Period. I know it - I have it (the Freickert software...) at hand.....
So my post was purely for clarification too.
D. |
Dear Jtimothya, to determine the correct output for each channel you do not use a test record.
Maybe. The goal is merely to compensate for channel output differences prior to taking readings for the purpose of setting a decent azimuth. Whether you use a stylus cleaner or the stylus moving in a groove cut for a known frequency, the net result of what you're doing is basically the same. The cartridge doesn't know where its input comes from. If you have a point it seems to be about the specific frequency used to put the motor in motion. From what I know the methods described in my post have yielded proven results. Thanks for your comment. . |
It reads "correct" and "each channel" and your cartridge (and - btw - me too...) do see some important difference between tracking a groove wall with most likely misaligned azimuth or being forced to generate output independent of stylus position ( one channel is always louder if azimuth is off....) ...... but if your method gives satisfying (or "proven") results for you - great! |
Dertonarm,
I don't think there is much else to say about the functionality of the software. It's a transfer function that is, as I stated, independent of the difference of channel balance. Anyone with the software, or a spec an, or a true RMS meter can duplicate at least the transfer function to the limit of each measurement devices resolution. Of course the other options mentioned are more tedious. What one does with the repeatable information obtained from this exercise can be the subject of debate which I will not enter into since I'd much rather listen to music than engage in turf wars about subjective opinions.
I guess we will agree to disagree since I know I can (and have done so) duplicate the transfer function using several different tools to benchmark what my [b]ears[/b] tell me.
I appreciate your interest in this discussion and how you are sharing your understanding of how you think the software works.
In the end the software is a tool, a very nice one IMO for analog applications, to be used to help the listener find satisfaction and enjoyment in music reproduction. Does the software work as I stated? Yes. Is it the final judgment on satisfaction of music playback? No, that would be the individual music listeners contentment with the quality of music playback or at least is should be.
Dre |
Joel,
Id like to follow-up on the second part of your post with regard to Azimuth adjustments and crosstalk measurements being different for the frequencies you mentioned above.
Based on a couple previous checks and another sweep of my cartridge last night, the crosstalk was constant across the frequency spectrum with a bit of drop (overall but still consistent) around 18-20 KHz. Potentially, a contribution in those higher frequencies may be due to sampling rates (or limited samples captured) at those frequencies.
However, the readings and results show that there are cartridge designs with measurably consistent ( and admirable) azimuth related crosstalk results over frequency. I'm not sure if this helps or ends up being useless information suitable for Jeopardy. In any event, you sparked my interest to recheck some old data/notes and check it in a more exhaustive manor this time. Now Im glad I did it.
Its nice to know how to get back to (or at least close to) what our ears tell us sounds right a little quicker.
Thanks!
Dre |
Indeed there isn't much more to say about that software. Being one of those "anyone with the software", I can tell from personal experience that it has its faults and does not function for azimuth adjustment. A basic reflection error remains a basic error - even if masked with a nice user interface. That this error isn't realized by some doesn't mean it isn't there.
But errors are certainly human and no problem in analog set-up - if only they look smart and fancy. |
@Dertonarm: As I can read from your posting(s) you didn't even read the manual properly...
The software doesn't balance outputs at all!
Cheers,
Chris |
@Feickert: as I can see from your post, you haven't read my posts. Or didn't understand them. I didn't say that your software would "balance" the outputs at all. |
Hi Dertonarm, so the following lines were not written by you? As for the Freickert-software... it implies for correct function in azimuth-adjustment mode, that both coils of a given cartridge do have 100% identical output.
If this is not the case - which you can count on in 99,99999 % of all cartridges - it will help you little to adjust azimuth. As it compares output of both channels to give identical readings. Well, maybe I need a visit at my doctor to have a general check of my eyes..... Cheerio, Chris |
As I understand it, the goal in adjusting azimuth is to minimize crosstalk between channels. This means that the amount of crosstalk will not necessarily be equal for both channels (in fact it almost never will be equal) but merely that it will be as low as possible for each channel. The goal is not to achieve equal crosstalk but rather minimal crosstalk. (This usually involves a compromise in my experience doing it with a Signet cartridge analyzer and a test LP; when you get to the lowest crosstalk for one channel, the crosstalk in the other channel is frequently unacceptably high and can only be reduced by adjusting azimuth further, such that there is some small sacrifice in the db of crosstalk for that first channel one measured.) As one plays with azimuth by ear crosstalk reaches a happy medium, which we hear as "good soundstage". I am not familiar with the Feickert method, but if indeed it does allow one to measure and minimize crosstalk, it should work to bring one closer to "goodness" (optimal soundstage). The fact that nearly all cartridges will have slightly unequal outputs between channels will have no effect on this process, although it probably has a small effect on the actual numbers of db one measures. This is assuming that no cartridge that is not "broken" will have more than a 1.5db or less difference in absolute output between one channel and the other. Ergo, I would say that DT is off-base in his statement that one must know the difference in output between channels (which anyway one could measure) or that a cartridge has to have perfectly equal output between channels, to properly adjust azimuth using an electronic device.
One of the main reasons I bought my Triplanar many years ago was the demonstration of the effect produced when azimuth is properly adjusted and the ease with which this goal is achieved using the TP. I am really rather shocked to learn that the DaVinci has no provision for this important facet of tonearm function. |
Lewm,
Thank you for redirecting this thread towards the realm of commonsense.
No, the magnificent DaVinci Grandeeza tonearm has no provision for azymuth adjustment. Would appreciate it if anyone could comment on the pros and cons of this design decision. |
Pro: Most mechanisms for adjusting azimuth introduce some compromise into the rigidity of the cartridge-headshell-tonearm-pivot linkage. Leaving out the adjustment eliminates such theoretical "issues".
Con: You cannot adjust azimuth. You therefore may be missing some of the wonderfulness that comes when soundstage snaps into place and sounds "right". As has been said, you may be able to correct azimuth by the judicious use of shims here or there. But after living with the TP for the last 15 years, I would hate to go back to that method. |
Lewm: While the Feickert software measures crosstalk, it also measures phase, to which the ear is more sensitive. The azimuth angles at which crosstalk and phase error are minimized don't always coincide, although they are often close. Since minimum phase error is of most interest, whether the channel output levels are identical is not so critical. Several months ago I measured an exotic cartridge which had been problematic for a client; as it turned out there was severe channel imbalance on the order of 4.5 dB, so it was replaced with a conventional cartridge...the improvements with the azimuth about 2 degrees off level were mind blowing. |
Does anyone know of a source for washers/shims that will alter azimuth by 0.5 degrees?
I'm interested in Dr Feickert's software and have two tonearms with no built-in provision for azimuth adjustment. I understand I will need to do 5 (or 9) measurements in 0.5 degree steps, and it is apparent how washers can be used for this, but I'm not sure where I can obtain washers that are exactly the right height.
(I haven't done the math (trigonometry) to determine the required washer thickness to cause a 1/2 degree change based on the distance between cartridge mounting screws -- but, even if I do that calculation I don't have a tool to measure that height with the accuracy I need.)
I know that Dr Feickert's kit includes a spirit level, but that does not seem useful in my case as it is not the angle of the headshell that is being altered but, rather, the angle of the cartridge below the headshell.
Thank you! |
Hello Ebalog, 0.5 degrees is FAR too coarse of an increment for setting azimuth. I don't care what the numbers tell you. Now, you could get lucky and effect an improvement (say for example that you're off by 0.7 degrees and reduce the error to 0.2), but the odds are against your geting your azimuth dead-on. If I recall, Wally used to make a device that mimicked one of the Ortofon(?) cartridges - essentially, a knife edge pivot that runs longitundinally along the cartridge body and between the two mounting screws. The idea is to tighten one screw and loosen the other in order to induce a tilt - with contact between the cartridge body and headshell consisting of the two screws and the knife edge. Now, the obvious problem here is that you're introducing another material interface between cartridge and headshell. You're also changing the contact surface area. Either change could have an overall deleterious effect on the sound ... or not (not even considering azimuth changes). You might try experimenting with various materials and actually improve things from an energy transfer perspective. You never know where you're going to end up in this ballgame when it comes to material interfaces, and keep in mind that what works for a titanium cartridge body may well not work with aluminum, coral, ebony, etc. Try a thin strip of copper. It's easy to cut with a pair of scissors. You should be able to find it in a hobby shop, or alternatively, over here: http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding.html. You might also try aluminum foil. Cheers, Thom @ Galibier |
