I've only just discovered this thread and will now buy a DMM. I've never felt comfortable with the rod as, using it means I have to allow for its weight on VTF (which then usually messes up my azimuth setting) - or set azimuth statically which takes centripetal out of an equation it surely must be in?
SO - A QUESTION (if there is anyone still out there...)
My understanding is anti-skate mechanisms are used to negate the centripetal force - but this varies across the record. Hence, in part, HW's assertion one anti-skate setting isn't The Answer. However, that same varying (residual) force tends to cause a cartridge in a unipivot to lean a little. Doesn't this mean the azimuth will also vary across the disc - and negate our search for extreme accuracy of azimuth, landing us back in compromise territory? If I'm right where on the disc is azimuth best set as a compromise? Centre, edge, middle??
Or am I speaking Horlicks here? |
I use the Adjust + and it is not for setting azimuth to every LP you listen to.
You use the test LP from Feickert and it measures crosstalk along with phase angle. VTA will make changes to the measurements as well on some cartridges. I find it a bit of an "art" to interpret the results with this tool. You want to choose the azimuth where the phase angle and crosstalk intersects or very close. |
the new soundsmith counter intuitive 49.95 placed on the tonearm counterweight solves the problem a simple device that does work...allows you to really fine tune the vtf and asimuth after u get a ballpark reading without loosening the set screw ,,, |
Yes, my system does have that locked in quality just from carefully leveling azimuth with the rod. I think I will double check this with a DMM for about $40. I'm not sure I want a $400 tool that makes me feel like I need to check azimuth for each record. I guess the next step would be to buy a separate alignment protractor for each record! |
Sonofjim, yes, the adjust + is what I was referring to in an earlier post. From what I can gather, the perfect azimuth adjustment can change from record to record, depending on how it was cut. The Adjust + allows one to make azimuth absolutely correct for each record. I know this is ultimate, but hey, fiddling with VTA is enough for me!
As for setting azimuth by rod, I think Viper z's situation makes it clear that the DMM method is the only definitive method, and an absolute necessity. It appears his cartridge is defective, or at least out of tolerance. The DMM method and results gives him the ammunition to be able to go back to the dealer or manufacturer for an exchange or refund. He would have never known this without the DMM.
Having said this, and I did mention this to Stan, I do think an experienced audiophile who is well acquainted with the sound of his particular system could set correct azimuth by listening only. With a high resolution system you can hear when that sound is 'locked in'. Even then, I still like the DMM method as it gives comfort knowing you have the optimum setting.
For the perfectionists among us, the Feikert tool will be the ultimate. |
The DMM and Cardas gives excellent results...but so too does the rod method if done carefully. The DMM method is a bit of a pain to go through the hoops, but the results are very clear. As I have said in another post, if you reduce the distance between the record and the rod on both sides (I use the Cardas Myrtle blocks, and build it up even further with the same size washer for each of the 2 blocks - one on each end, under the rod ends), and if the rod is not bent, and if the stylus was manufacturer square to the cartridge body, the results are the same. As you can see there are a lot of "ifs", however, it can be done. I would save the 500 dollars for more meaningful projects |
I've always set the azimuth up on my SSM by the rod/ear method with good subjective results. I'm considering double checking with a DMM based on what I've seen here and elsewhere. There appears to be a new option from Feikert in the form of software called Adjust + which looks like azimuth is set with an oscilloscope on your computer screen. I think this runs 400-500 dollars though and I've been trying to find input from someone who knows more about it or has used it. Is it worth the expense or can I get similar results using a DMM and Cardas test record? |
Sns, of course, I tried turning the other direction and the voltage increases instead of decreases. |
The only thing I can think is that the cartridge is at fault. If your output is equal on both channels, crosstalk measurements should be pretty equal as well. I would expect with cartridge manufacturing tolerance variance you will likely never get crosstalk to be perfectly equal between channels, but you should get much closer than you have. Have you tried turning the tonearm weight in the opposite direction, perhaps you're turning in wrong direction. Someone else has some ideas? |
Hmm...I tried the DMM method for the first time. I bought the $40.00 Analogue Productions Test LP. I first played the stereo mode 1kHz tone and turned my volume up so that the output voltage from my amp reads about 4V on both side.
Then I played the left 1kHz tone and measure the right output voltage, I got very unstable reading between 0.02 to 0.08V.
I then played the right 1kHz tone and measure the left output voltage, I got between 0.22 to 0.3V.
So now I turn the tonearm weight in one direction to try to get my left output voltage to fall below 0.1V. But the funny thing is, even when I turned all the way to the extreme position, the left still measure between 0.17 to 0.26V. There's no way I can get it to the same small reading as my right output.
So does this means my cartridge is faulty or what? |
Radrog, in fact I do live in Michigan, near Ann Arbor. Send me an email if you're serious. Scott |
If you live in Michigan come on over..... |
Rsrex, yes, this is the point I was trying to make when speaking of variability in manufacturing tolerances. The DMM method is the only method that accounts for all those possible deviations.
As for those who think this is a big hassle. What is the hassle of having a DMM and learning how to use it. If you consider this a hassle, you will be one frustrated audiophile in time. This hassle pales in comparison to many others I've faced through the years. Once you've used the DMM method a few times it becomes much easier, I correctly set azimuth for a Valhalla wired tonearm in about 15 minutes the other night.
|
Rsrex, I agree with your point. This makes a good starting point for what ever method. The best method as you stated is using a test record with a true RMS meter. Either at the speaker posts or better yet, the phono pre-amp. Some people do not have the patience or want to spend the money on the gear to check all possible settings. This is the close enough for goverment work mentality for some people.
Secondly, As much as some cartridges cost, they should be level. |
The problem with this is that all you have done is level the headshell. It doesn't necessarily mean you have adjusted for the best azimuth. Azimuth is best adjusted by minimizing crosstalk between channels. If the cartridge is perfectly assembled, that point may come when the headshell is level, but don't bet on it. |
When setting up my Scout, I discovered a trick for setting azimuth.Working in medicine I have access to long hollow needles that I cut to @ 6 cm length. I place the needle in the headshell groove and rotate the album 1/2 turn clock-wise with my finger on the outside edge so the tonearm self centers itself. Look at the level again, carefully twist the counter weight in the opposite direction and rotate the album 1/2 turn again.Keep trying till you find the tonearm level. DO NOT let the album move in the opposite direction. |
I set the table up the first time with a Sumeko Celebration cartridge and just the VPI Jig and it turned out perfect. |
What do I need to purchase to make it rite????? |
I will be putting a Goldfinger on a VPI with unipivot jwm arm. I guess I have alot to learn. |
Radrog,
Didn't you mean, "Get a BAD cartridge and forget all the nonsense"? ;-)
The more resolving the cartridge the more it responds to changes in azimuth and other setup parameters. Low resolution cartridges do mask the effects of many adjustments, but I'm not sure that qualifies them as "good"!
|
Get a good cartridge and forget the nonsense. |
Yours is a post that EVERYONE should read!!
To do it optimally you need two (2) ANALOG AC Voltmeters. One will do it though OR an audio analyzer (preferable) OR a cartridge analyzer. You also need a proper cross-talk LP - preferably one that has each channel on a separate side of the record (thereby providing maximum separation). Cross-talk records are generally not easy to find.
Yes, it IS a PITA - but so worth it! |
Sorry guys...I didn't know what I was talking about. There are two output posts for each left and right channel on the back of my amp. Case closed. |
Guys, pls help a newbie here. I have never used a multimeter before, but I know that it has two probes (+ and -). At the back of my amp there's only two output (left and right). So if I'm going to measure the right channel output voltage, I connect the (+) probe from my multimeter to the right output post of my amp, where should the (-) probe goes?
Thanks
VZ |
Yes. I agree. I actually got it right using a rod; after changing the way I measured the distance.
But, I would not have 'Known' I was right without the meters.
Jerry |
In fairness...I checked my settings that was done with the rod as I mentioned above, and then checked again with my newly acquired DVM, and found that my original settings were good as is. If you are very careful, it is possible to do it correctly with the rod. |
SNS, thanks for bringing this up.
I finally got in from work, bought another meter, the Fermer DVD and the test record I needed. After just a few adjustments I am sure my azimuth is correct and the soundstage is fuller.
Thanks again, Jerry |
Mark, I purchased my DMM from partsexpress.com, item no.390-545. $25.50 plus shipping, pretty good deal. Radio Shack also have them, slightly higher prices. Scott |
The center image on my system was shifted slightly to the left. I thought I had the azimuth set quite close with the VPI rod. Then today I found a DVD that had quite a large center area with a mirror finish, and then I set that on the platter and saw the cartridge was tilted. I made a couple of small adjustments and POW the image snapped to the center. Next step is to check it electronically.
Mike |
I have a VPI Scout. Where can a I get a DMM? Which one should I get? Thanks! Mark |
Here is an interesting web page discussing a new tool for dynamically setting azimuth. http://www.adjustplus.de/index.php?lang=english |
Thanks for this thread, I just ordered the test LP and I already have the Michael Fremer DVD and several multimeters. This method just seems to make the most sense.
Mike |
Yes, postive goes to positive and negative to negative, unless your phono pre or pre inverts signal (as my preamp does) in which case positive goes to negative, and vice versa.
Leave speakers hooked up.
I did not recheck with the rod, I don't see the point. The electronic method is much more precise than the rod method, I will never use the rod method again. |
When attaching the test leads do they go pos to pos and neg to neg at the amp output terminals? Is it ok to leave the speakers hooked up? After you got the channels balanced did you use the VPI rod to see how close to level you are now?
Thanks,
Mike |
No. Crosstalk is the migration/blending of signal output from one channel to the other. Thus, left channel signal leaks into right channel, and vice versa. Using the balance control only controls gross decibels, the ratio of crosstalk (leakage) to proper signal remains unchanged.
Only by getting the stylus to ride perfectly perpendicular to groove walls will you get minimum crosstalk. The Fremer dvd explains this very well in the PDF files. |
Thanks for starting this.
I ordered the DVD today and will check it out.
If you have a small difference wouldn't the same end be reached by adjusting the balance to even the dB output? |
Details, details, details! I almost forgot. While these reading may seem miniscule, each .001 represents half a decibel, small readings will be typically between .010 to .023, this correlates to 0 to 7.5 decibles. .002 is equivalent to 1 db, I assume we can hear this difference.
My initial readings, using the VPI rod method, were .011 and .019, a difference of 4.5db from one channel to other, it can be no wonder images were so unstable and sound less than involving. |
Jamnperry, there is the Analogue Productions test record, this even may be better as the 1kz tracks are longer.
Kotemaori, I would think they have you measure at the speaker outs in order to get the readings closest to what they would be coming out of your speakers. Therefore, taking into account the IC's between phono pre and preamp and preamp to amp, preamp, amp. It would be interesting to test at both output of the table and amp outputs and see what differences there are.
I also mis-wrote the acceptable tolerance in one of my posts as 5-10%, wrong, the acceptable tolerance is 1-5%.
I've also thought about a possible means to test electronically without the wally conversion table. You may be able to get azimuth to proper specs just by reading small reading (the actual crosstalk) in each channel.
Procedure: Play a 1kz stereo test tone and set volume to output 3ac volts (DMM at 2acVolt setting, it will read as .300 or close) at amp outs, test both channels, adjust and balance volume accordingly. Now play the left channel only and right channel only 1kz tracks. When playing the left channel tracks insert the DMM probes into the right amp speaker posts (in phase), write down the reading, you should get something between .010 and .023 or so (DMM at 2vAC scale). Play right channel, place probes in left channel, write down reading. If you have a reading that deviates more than .002 between the two you can be sure to be out of tolerance. The best I was able to achieve was a difference of .001. To reiterate: You want a differential reading of .000 to .002, no other reading will be within tolerance.
I cannot guarantee this method is best, but my own readings on big and small voltages show this should work. |
As a total novice when it comes to measuring with DMM, my first thought on your method of measuring at speaker posts is that you are also measuring the differences in the power amps, would it be more useful to measure at the output of the t/table (i'm using TNT HR) |
Is there any other test records besides the Cardas with the 1khz tracks? I used the rod method but would like to check it electronically. |
While we are on the topic of cartridge allignment, it may be interesting to note that the vacuum state website (in their white papers) has another take on cartridge allignment. I have not read it in detail, but it may be worth further exploration. |
Almost forgot, another thing that may result in azimuth error is how tight each screw is. At one point in the midst of doing my measurements I had gotten crosstalk deviation within specs, I decided to retighten the cartridge screws just to be sure, this changed crosstalk deviation beyond specs.
To reiterate, my experience teaches me no physical measurements protocol will result in proper azimuth settings. One may get lucky and find the mark, but for proper azimuth it is absolutely necessary for an electronic measurement.
With practice this method is actually quite easily accomplished, not rocket science here. Purchase or borrow the Fremer video, the PDF files alone are worth the price. Actually, now that I think of it, it may be necessary to buy that video as it has the Wally azimuth voltage to decibel conversion chart that is absolutely necessary. It may also be available elsewhere on the web for free, I haven't checked. You also need a record with 1kz test signal for both left and right channels, I used the Cardas record. |
Jerry, the ac voltage scale should be at the 2 scale, the 20 scale is not low enough for precise readings.
You measure at the speaker binding posts on your amp.
Stingreen, it would be interesting to measure your crosstalk with a DMM. I contend the DMM method is by far the most precise method because of production variations in tonearm mounting pads, cartridge mounting surface, cantilever, flatness of record, and in your case the Myrtle wood blocks. In the case of VPI's method you also have the possible variations in straightness of rod, ruler precsion and reading it.
My initial reading after having set azimuth according to the VPI method was around 20% deviation in crosstalk between channels. I also found that inperceptable movement (with the naked eye) of the counterweight resulted in quite different crosstalk measurements, ie., what may measure equal using any physical means may still not be within the 5 to 10% crosstalk tolerance level. Also, there may be added value in getting it down to about 1% vs. 5 to 10% tolerance level(I didn't listen to musical passages at different crosstalk valuations).
Your suggestion of tightning up the counterweight set screw close to its stop could be very helpful, I had the screw set loose which may have resulted in counterweight moving about too easily. Also, I wasn't setting VTF and azimuth in discrete steps, I already had the VTF set correctly. It was in trying to move counterweight about it's axis that I was inperceptably moving counterweight forward and backward which changed VTF, your suggestion of pre-tightening some may help in keeping this from happening.
Slowhand, I took it for granted the VPI allignment jig was correct. In the Fremer DVD he does allignment with the Wally tracker and it jibes perfectly with the VPI jig. I will have to go back to my DB protractor and double check allignment. |
How low does the A/C voltage scale on the Digital Multimeter need to be?
And where do you measure it?
Thanks, Jerry |
You guys are absolutely correct. Turntable setup requires a lot of patience and careful adjustment to reap the benefits of that big money outlay. Also, we usually put a new cartridge in the new turntable/arm. The cartridge will be in constant flux...mine was for over 150 hours. What store is going to have that kind of time to put in no matter how much they charge you. Its really not that difficult to set up an arm/cartridge if you are careful and do it yourself. Regarding the JMW arm. When you set it up, don't tighten the Allen screw on the counterweight very tight...this enables you to "coax" the counterweight to accomodate azimuth and VTA without the counterweight moving. Tighten it when satisfied...much easier than trying to do each adjustment seperately. The method SNS used is fine...the rod thing works as well, and the JMW alignment gizmo is fine if done with care..as with all of this. Regarding azimuth adjustment... It is difficult to judge the distance from the rod to the record and have it be equal on both sides. I took two Cardas Myrtle blocks and placed one on each side, then took other wood block of slightly narrower height and put them one on top of each of the Myrtle blocks. The combined blocks both just fit under the rod edges when the arm is perfectly level and sitting on a non-moving record. This enables you to set the arm absolutely level, but in a poorly manufactured cartridge, the stylus may not have been mounted square to the cartridge body. I double check the azimuth by using a top silvered mirror (get it at a camera repair center). Put the arm on the mirror, and carefully look closely down the front of the cartridge. The cantilever and stylus must sit perpendicular to the reflected image. If the stylus is leaning in either direction, I personally would replace the cartridge/stylus. |
You are right. Setting up the table correctly is critical. I have a VPI Aries 2 Extended table with a JMW 12.5 arm and a ZYX Atmos cartridge. I am lucky to have friends who are very knowledgeable about turntable setup. One of them has been helping me fine tune my table. The sound I am getting now is amazing! Extreme dynamics, huge soundstage, precise placement of instruments in the soundstage, plenty of "air" around the instruments, and fantastic sense of attack and decay of instruments. Vocals also have a "you are there" feel to them. Don't even bother setting up your VPI with the jig that comes with the table. The only way to go is to set up with the Feikert protractor. |
