I'll take you at your word the arm is properly configured. There are parameters other than VTF and VTA. Some you can control and other are set when the arm is attached to the plinth.
However, two issues. First, a pivoted tonearm scribes an arc across a record. That means you can only achieve a good average for being perpendicular to the groove. At most spots on the record, you're going to be slightly off. Change a setting to perfect that for one spot, and then you're off at others.
Second, since the diameter of the record decreases as move toward the record's label area, the spiral of the groove's arc tightens. That inherently increases distortion.
One problem could be that a record may have subtle permanent damage from prior playing. If that's the case, you may be stuck with the distortion. However, I would expect that condition to vary quite a bit from record to record in your collection.
While inner grooves inherently have more issues than the outer ones, that shouldn't automatically mean audible problems. If every record has the problem, I think you're back to a setup issue. You might try rechecking if the distance from the pivot point to the stylus is correct, and also double check to make sure your cartridge doesn't yaw to the left or right. Also double check the anti-skate setting. The centrifugal force increases as the spiral tightens.
Thanks Misstl. I'll experiment with the tracking force. If centrifugal force increases as the spiral tightens, is it better to adjust tracking with a bias towards more or less force. I assume that the readings on the gauge are just estimates anyway, so I would think changing anti-skating force is at best a rough estimate of what's needed.
I think your comment regarding the condition of my records may be correct. The inner track distortion does vary somewhat from record to record, but even still, there seems to be more distortion coming from the inner tracks of even the better records.
Your comment regarding perpendicular arms causes me to remember the old days when the Rabco arm was the state of the art. However, for some reason, I suspect that even straight tracking arms present their own engineering problems. I guess that's why most arms are still pivot types.
Do you think that a better modern arm, like a Rega RB 301, would do a better job? I was thinking about an upgrade anyway, matched possibly with a Clearaudio Maestro Wood or Ortofon 2M Black cartridge.
One other possibility is they missed something in the reconditioning of your Thorens - perhaps a tonearm bearing that is a bit worn, dirty or under-lubricated and has a bit more resistance toward the label area.
You might check if a local dealer will let you demo a newer turntable. If the problem goes away with the new model then you've clearly established the Thorens needs a bit more work.
I just had this same issue. I tried EVERY adjustment possible....and still did not fix it. Turns out my arm was not mounted in the correct position. Make sure that the distance from the platters' center to the pivot point is the same as the manufactures specifications. I changed to the correct armboard, set it up using a protractor....and now it sounds like a dream!
Sounds like an alignment problem.
Less likely is a worn stylus.
Audiofeil and Macd: As I mentioned, the tonearm is the original stock TP16, which came with the TT. Audiofeil, when you suggest that there might be an "alignment problem," what are you referring to? The cartridge, azimuth, overhang??
Thanks for the thoughts.
Would you say that there is equal distortion in both channels?
Make sure your cartridge is lined up with a protractor, if the cart physically looks like its level, I dont think azimuth would be the issue (could be wrong about this). Overhang is related to alignment, a protractor should take care of this.
Until you do this, you will never know. Just search for a free protractor for your arm on google. Expensive protractors are more accurate, but at this time you just want to get it somewhat dialed in so that you can eliminate variables. If all this is correct, I lean to four possibilities:
1)Your cart is not a good match for your arm (checked already)
2)Somehow the arm is not installed correctly (measure this!)
3)table is extremely off level (maybe why the Anti skate affects the issue)
4)software issues (very hard to test this since some records simply track better, even on a poorly set up TT)
Thanks Macd. When I called Grado, they said that the Sonata likes a 2 degree VTA, north of 180 degrees - flat. That is, the cantilever/stylus should "rake" a little bit. I'll need a protractor and allen wrenth. I'll report back after I checked VTA and made the necessary adjustment, if needed.
Im thinking on this one.. its not very typical and when I was in the business I did over 2000 turntable setups. So lets start with what its not
1) stylus problems exhibit throughout the record
2) alignment problems don't manifest this way
3) General arm problems are agnostic to position on the LP
The times I have seen issues with groove position have all been mechanical issues
noise at the juncture between inner and outer platter assemblies. mat design or aging issues where the mat isn't making good contact with the inner grooves
binding in the bearings because the platter is tilted relative to the arm. Issues with the antiskating mechanism binding or increasing drag during travel due to corrosion or dust. Counterweight mods touching the gimble at the end of play
one last thought. Its better to track about 0.25 gram heavier than the nominal/minimum weight recommended. This insures that inner grooves, irregular records maintain good stylus contact. Many myths about lower stylus pressure being better, in point of fact degraded tracking and worn stylii are what damages vinyl. I usually run my Grado Signature at 1.7 gm. This is kind of basic but I shouldn't assume you alredy know.
Sounds like God is telling you to upgrade...
David256 & Syntax: Thanks for the advice. I tried increasing stylus weight by .25 gm. That helped a bit. But I think Syntax may be right -- time to stop nursing the Thorens along and get a new TT and arm.
Don't be fooled by Syntax's sarcasm. ;-) What you are describing is the classic definition of mis-tracking due to improper alignment. Listen to Macd and Audiofeil. You need to learn to do this correctly yourself, or find someone local to you that can do it. It is surprising how "off" one can be and still get good sound.
VTA is basically stylus geometry, groove tilt. Its importance is determined by complexity of stylus shape...a simple elliptical like the Grado signature only has to be approximately right. Other more complex shapes become critical because the actual stylus playing edge is shaped/directional. VTA doesn't care where you are on the record circumference.
Alignment is basically trying to get the stylus parallel to the groove to the best approximation possible. I say approximation because with a round record and pivoting arm you will start to deviate slightly as soon as you leave your measurement point. If alignment is badly off stereo imaging is compromised because you read one channel ahead of the other.
None of these generate tracking distortion, only loss of musical detail.
Its entirely possible that all that is needed is a record weight or clamp to insure tight contact between record and matt because the record label height is causing space and vinyl resonance thats damped further away from the label. If the matt itself has no concavity for the record label area a better mat should be purchased.
Thanks Davide256: Your advice is helpful for all A'gon members who own turntables.
As far as VTA is concerned, based on the posts above, I will need to purchase a protractor. Where's the best place to get one??
Regarding alignment, I take your point about a round record and pivoting arm. How do I check and adjust alignment? Because I'm dealing with a stock arm, I assume the only adjustment I can make is moving the cartridge backward or forward in the mounting shell.
Finally, the mat and record clamp are great suggestions. Again, where's the best place to pick up that stuff? BTW, if the record clamp is heavy, I surmise that the extra weight could prematurely wear the TT platter bearing. Do you agree?
Thanks again. BIF
the Pro-Ject Align it Cartridge Allignment Tool
($169 at Needle doctor) is very similiar to the Denneson tool I used. This had the virtue that you could lock it into position and was accurate regardless of the spindle, arm bearing center distance because you adjust it to that distance. It also provides a mirror surface so that you can check and adjust the cartridge body to be parallel to the record surface. You can craft a tool yourself by taking a flat record size disc, etching a right angle, drilling the center hole for the record spindle, then etching a 1mm line separated grid at the mid point of the record playable area. I've seen a number of this design but they are a PITA because you use line of sight for the arm bearing center and its hard to adjust without accidentally moving the platter/alignment disc.
Alignment actually requires rotation ofthe cartridge body for final adjustment. There should be enough play to make the needed adjustment if the arm pivot point is located at the manufacturer designed distance from the record spindle.
I prefer clamps to weights, more pressure on the record, less weight on the bearings. height can be a problem with a closed dustcover. Sota products are good but pricey and tall. The JA Michell record clamp should be a good choice to avoid height problems, also available at Needle doctor.
Davide256, thank you very much. BTW, I checked Vinyl Engine for cartridge alignment tools. They have some very helpful and inexpensive tools available there, even some custom set ups for Thorens TTs. Thanks also for the advice on the TT clamp vs the weight. That makes a lot of sense. I'll make the adjustments and come back with a report. I've gotta believe that there are many other folks in the same position as me. So many thanks for the great advice!
on a related track, I highly recommend use of a record cleaning machine like Nitty Gritty with fluid scrub and vacuum suction. Airborne dust and stylus deposits hide detail and cause increased stylus wear so there is an easy to justify pay off. Beware of cheap substitutes as most of the benefit is driven by suction power and a suction design that insures the groove is wet scrubbed right before suction occurs.