[robbiesurp]

I wonder if my mint is set to the wrong s2p distance? I purchased it right after the Classic was first released. I also have a stainless steel arm wand,not the stock aluminum.

So just to clarify (comparing the 2 alignments):

Vpi jig effective length: shorter
Mint effective length: longer

Is this correct?

[Wayner]

Then I have to ask, is VPI inventing new alignments? WTF?

Here is the problem: pivot to stylus distance are directly and mathematically connected to offset angle. With one correct and the other incorrect, it can't work. I would suggest that for a day, you abandon the VPI alignments and go with some traditional stuff that has both overhang and offset angle in harmony.

Wayner

[Sonny]

I wonder if my mint is set to the wrong s2p distance? I purchased it right after the Classic was first released. I also have a stainless steel arm wand,not the stock aluminum.

So just to clarify (comparing the 2 alignments):

Vpi jig effective length: shorter
Mint effective length: longer

Is this correct?

Should be the other way around.  I found the VPI jig gives a longer S2P distance than the conventional...

[Gzerro]

Then I have to ask, is VPI inventing new alignments? WTF?

Wayner

Yes. As I understand it, VPI "invented" a proprietary alignment. This is one of the reasons I bought the Mint Tractor so I could at least have a known alignment for comparison.

Now I am realizing that either the Mint Tractor I received or the VPI jig I have are not correct. When using the Mint Tractor I get a result that the stylus is actually in front of the VPI jig alignment point by about 1mm, so it is off by about 3-4mm from what the picture Robbiesurp posted would seem to indicate is correct, and what Sonny confirmed should be the case.

At this point I am going to assume the Mint tractor is incorrect since it is a one-off hand made item vs. the mass produced VPI jig. Temporarily I will need to use the VPI alignment.

I will post back once I get either a fixed Mint Protractor or a different tool. Maybe time to get Wayner's tool from AVA.

[neobop]

Gzerro, Wayner,
Sorry, misconceptions about a different alignment -   ANY 2 null points along the grooved portion of a record will yield a "proper" alignment.  You might prefer one to another, but an alternate alignment is nothing to get excited about.  I suspect the VPI alignment is close to Baerwald and probably slightly toward Stevenson which maximizes alignment at the inner grooves.

If you want to check a protractor to see what it is, or close to, measure the distance from center spindle hole to the inner null. They are:
Stevenson - 60.325
Baerwald - 66.0
Loefgren - 70.3

Baerwald is by far the most popular alignment.  Go to VE and calculate error at the beginning of the record for a 9 or 9.5" arm.  You'll see that the numbers for Loefgren are unacceptable (to me).  The reason Loefgren has the lowest total error, is because it maximized for the middle where error is the greatest.
Baerwald gives the most even sound at beginning, middle, and end.

BTW, an arc protractor should only be used if mounting distance is exactly right for that arm/protractor.
You should NEVER arbitrarily change toe-in or the alignment angle at a given null, that is if you want to keep some semblance of a rational alignment.
I think you should try the VPI alignment.  It should coincide with the offset of the headshell and might solve the problem, especially with a unipivot. You never know.

According to the VE data, the three 9" arms have eff mass of 7.7 or 9.5g.  Is that incorrect?,


Robbie,
If that's a low compliance cart you're using you might want to give the steel armtube a try.  I'm not sure exactly what's going on here but the other tube might be better.  I also suspect the tube coupling.  Maybe that could be damped somehow, or made more rigid.

neo




 

[Wayner]

So if we had 2 null points that were 10mm apart, that would be good? The answer is that all alignments offer trade-offs between maximum tracking error distortion with regards to null points. Stevenson puts the highest amount of tracking distortion at the beginning of the record and very little at the lead out, because the inner null point is close to the label. Baerwald and Lofgren B kind of average it out, giving Lofgren B the edge for having the least average tracking error distortions.

What does all of this mean? It means that setting the cartridge to one of these alignments, creates the offset angle of the cartridge. Since the record was cut using a linear tracking lathe, it is best to attempt to duplicate the straight line movement as best as possible with the arc of a single point arm. Having the least amount of offsets angle is going to improve the situation for the OP.

I don't align my turntables to which one is the most popular, as most folks don't really understand the geometry in the first place. Alignments shouldn't be about a popularity contest, they should be about particular needs of the listener. As an example, if someone I knew listened to classical music all the time, I would recommend the Stevenson alignment (with reservations) as most classical records go way out to near the label and are very dynamic, even at the end of the record, where the recording is the most compressed for info.

Wayner

[neobop]

So if we had 2 null points that were 10mm apart, that would be good? The answer is that all alignments offer trade-offs between maximum tracking error distortion with regards to null points. Stevenson puts the highest amount of tracking distortion at the beginning of the record and very little at the lead out, because the inner null point is close to the label. Baerwald and Lofgren B kind of average it out, giving Lofgren B the edge for having the least average tracking error distortions.

What does all of this mean? It means that setting the cartridge to one of these alignments, creates the offset angle of the cartridge. Since the record was cut using a linear tracking lathe, it is best to attempt to duplicate the straight line movement as best as possible with the arc of a single point arm. Having the least amount of offsets angle is going to improve the situation for the OP.

I don't align my turntables to which one is the most popular, as most folks don't really understand the geometry in the first place. Alignments shouldn't be about a popularity contest, they should be about particular needs of the listener. As an example, if someone I knew listened to classical music all the time, I would recommend the Stevenson alignment (with reservations) as most classical records go way out to near the label and are very dynamic, even at the end of the record, where the recording is the most compressed for info.

Wayner

You can't have 2 nulls 10mm apart.  It's geometrically impossible for the length arms we're talking about.

Stevenson has less error at the beginning than Loefgren.  The outer null is closer to the edge of the record. Use the alignment error calculator and see for yourself.  Loefgren only has the least error because of the central grooves.  Both beginning and end are worse than the other alignments.  Baerwald is most popular for a reason.  It sounds best to most folks, whether they understand the geometry or not.

This isn't about the best alignment, whatever your preference.  It's about that right channel noise/distortion with the VPI arms and I seriously doubt if alignment is a factor here.  These people seem to know what they're doing and have $100 aftermarket arc protractors. 
As to offset, it might be best to use the offset designed for the arm.  I never used one so I can't say that with certainty.  It's a suggestion to try, not a prescription.  Maybe reducing offset will help - unknown.

I don't think any of this alignment crap has much to do with the problem.  Vibrations in a particular frequency range are being reflected back to the cantilever.  The solution is in the armtube, tube coupling, undamped pivot, or internal armtube damping.  The anti-skate situation in the orig 9" arm is a separate issue that impacted on, and enhanced the problem.

That's my guess and I'm sticking to it. 
neo


 

[Wayner]

I just threw the 10mm out there, and didn't even think about it for a minute. A little touchy are we. Stevenson has the greatest error at the beginning.

It certainly can be about cartridge alignment, cause that is what sets the offset angle. If you think that longer arms are better, then the longest alignment is better, because the offset angle is the lowest with the Lofgren B, PERIOD. It has an impact on tracking error and anti-skate.

[Wayner]

[Gzerro]

If you want to check a protractor to see what it is, or close to, measure the distance from center spindle hole to the inner null. They are:
Stevenson - 60.325
Baerwald - 66.0
Loefgren - 70.3

I just measured this.

The Mint LP Protractor is 66mm. The VPI Jig is 67.5mm.

Rechecking, it is clear using the Mint I am ending up with about 1mm more overhang.

Does this make any sense? Both tools seem pretty much idiot proof, but that has never stopped me from screwing up before.

[robbiesurp]

I get the same:

Mint: 66mm
Vpi Jig: 67.5mm

This is odd that we are ending up with opposite results of Mint vs VPI Jig overhang.

Are you keeping the arm tube parallel to the surface of the alignment gauge when you are setting overhang? I find that I have to reset VTA to account for the different thickness of the 2 gauges. Of course you also have to check the VTF when you change the VTA. I don't know if any of these factors might account for our discrepancy.

I'll check out the tracks on the Hi-Fi Test record and report back.

[robbiesurp]

VPI Classic 1 w/stainless steel tone arm(12.3 eff mass). Benz Micro Ref S Cart. Mint Tractor Alignment. VTF 2.2g


Hi Fi News Tracking Test:

4 tracks at the end of Side 1:
-Track 1: Clean
-Track 2: Clean
-Track 3: Clean
-Track 4: Distortion Both Sides

Side 2 tracking Bands:
-All Clean

When I first played the last track on side 2, I was getting some light high end distortion in the right channel. I twisted the tonearm wire one more time and the track plays clean. I have twisted the tonearm wires so many times back and forth that I have no Idea which setting is No Twist any more. So I'm not sure if I have 1 or 2 looser twists now.

I'll play some music and see if the extra twist helps.

[neobop]

I just measured this.

The Mint LP Protractor is 66mm. The VPI Jig is 67.5mm.

Rechecking, it is clear using the Mint I am ending up with about 1mm more overhang.

Does this make any sense? Both tools seem pretty much idiot proof, but that has never stopped me from screwing up before.

Should be the other way around.  Maybe your Mint is for a different length arm.  Either that or your arm mounting distance is off.  An arc protractor is rather straightforward you probably didn't mess up.   There is a possibility that you have the wrong VPI protractor? 

Maybe you should get a conventional Baerwald protractor and check.  It should be in complete agreement with the Mint.
neo

[Gzerro]

Should be the other way around.  Maybe your Mint is for a different length arm.  Either that or your arm mounting distance is off.  An arc protractor is rather straightforward you probably didn't mess up.   There is a possibility that you have the wrong VPI protractor? 

Maybe you should get a conventional Baerwald protractor and check.  It should be in complete agreement with the Mint.
neo

I am sure I have the correct VPI jig (the one for the 10.5 wouldn't fit). I verified my pivot to spindle distance is 222mm which is correct from what I am able to find.

I am sticking with the VPI alignment for now.

None of these setup changes have had any effect on the sibilance issue. I think your theory of the origin being something with the arm and/or cartridge is probably correct and this is just a red herring. I am going to follow it through though until I get it figured out.

Thanks again for all the kind assistance from Neo and Wayner.

[Gzerro]

I found a solution to the VPI Jig vs. Mint Tractor issue, mostly in this whitepaper:

http://www.vinylengine.com/vpi-tonearm-geometry.shtml

They are both correct.

Per the Whitepaper the VPI Jig for the JMW-9 results in overhang of ~16.8mm. Per Conrad Hoffman's arc protractor calculator (wow what a great little program), Baerwald alignment for JMW-9 should be 17.3mm overhang - just a bit longer.  This assumes 222mm pivot to spindle.

For the 10.5 Classic arm it is opposite. The VPI Jig overhang per the whitepaper for the 10.5" arm should be 15.6mm. Hoffman's calculator for Baerwald alignment indicates an overhang of 13.98 - a little bit shorter.

Lastly Conrad Hoffman's printout exactly matches the Mint Protractor.

 

[robbiesurp]

I found a solution to the VPI Jig vs. Mint Tractor issue, mostly in this whitepaper:

http://www.vinylengine.com/vpi-tonearm-geometry.shtml

They are both correct.

Per the Whitepaper the VPI Jig for the JMW-9 results in overhang of ~16.8mm. Per Conrad Hoffman's arc protractor calculator (wow what a great little program), Baerwald alignment for JMW-9 should be 17.3mm overhang - just a bit longer.  This assumes 222mm pivot to spindle.

For the 10.5 Classic arm it is opposite. The VPI Jig overhang per the whitepaper for the 10.5" arm should be 15.6mm. Hoffman's calculator for Baerwald alignment indicates an overhang of 13.98 - a little bit shorter.

Lastly Conrad Hoffman's printout exactly matches the Mint Protractor.

 

Nice work! Now it makes sense. I hope i didn't side track your thread with my protractor alignment questions. I now doubt that this problem has much to do with different alignment overhangs anyway.

I look forward to your further investigation. I've been trying to figure this out in my own system for the last 6 months or so. I think we are hearing a similar phenomenon. I've moved back to the VPI alignment as well and I'm going to try and make small adjustments to see if i can find the culprit.

Also, I noticed in your profile that your system is situated in an L shaped room. My system is in a room with a close wall (5 feet) on the Left side and an open room on the right side. Does your room also have a  wall on the Left side and no wall on the Right side? I have no idea if this would produce the effect we are hearing, but I'm curious if we have this arrangement in common.

[Gzerro]

Also, I noticed in your profile that your system is situated in an L shaped room. My system is in a room with a close wall (5 feet) on the Left side and an open room on the right side. Does your room also have a  wall on the Left side and no wall on the Right side? I have no idea if this would produce the effect we are hearing, but I'm curious if we have this arrangement in common.

My room is similar to what you are describing. It is along a "Long Wall" at the bottom of the L.  The left side is closed off, and the right side is open to the foyer. Also, behind the LP and to the right is open to the dining room.

If you want to test if it is a room issue, I would suggest just swapping the cables on the back of your turntable left for right. Does the sibilance move to the left or stay on the right? You could also try listening through headphones.

I am curious what you will find. I will try this also.

Tom

[robbiesurp]

Hey Tom, I switched the left and right inputs and the sibilant sounds moved to the left side. So it's not a room issue here at least.

I have noticed that overall the table is sounding very good with the VPI alignment and the phantom right channel sibilance is less frequent and lower in volume. It really is fairly subtle here, but just loud enough on some shh and ess sounds to draw your attention away from the center image. Also if a vocal is panned left I don't notice any sibilance in the right channel.
 
I balanced the tonearm and figured out which wire twist gives a slow outward motion, so I have 1 twist going right now.

I'll report back if I figure any thing else out.

[Gzerro]

Hey Tom, I switched the left and right inputs and the sibilant sounds moved to the left side. So it's not a room issue here at least.

I have noticed that overall the table is sounding very good with the VPI alignment and the phantom right channel sibilance is less frequent and lower in volume. It really is fairly subtle here, but just loud enough on some shh and ess sounds to draw your attention away from the center image. Also if a vocal is panned left I don't notice any sibilance in the right channel.
 
I balanced the tonearm and figured out which wire twist gives a slow outward motion, so I have 1 twist going right now.

I'll report back if I figure any thing else out.

I found the same thing pretty much, although once I got the anti-skate fixed the sibilance sometimes seems to come from the center or left, but still more frequently from the right. It took 2 twists on my arm to get to an amount of anti-skate that allows me to pass the test tracks.

The only suggestion I haven't tried yet is to use Lofgren B alignment per Wayner's earlier suggestion. When I get a chance to try that I will report back if it makes a difference.

[robbiesurp]

I was trying out some damping fluid on my JMW Classic arm and I noticed that the spike on the Unipivot base didn't seem as sharp. I'm gussing that this is a problem, but it may look worse magnified. Here are some pics from my cheapo USB Microscope:






I've tried to be gentle with the arm, but maybe I bumped the spike at some point. I'm guessing this may be the cause of the sibilance I can't get rid of. The pics are from behind the arm base, so it's bent toward the platter.
 
I've contacted VPI to see if they can help.