2. analog
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TT setup woes

I am having some difficulties in setting up a new (for me) analogue front end (Nottingham Hyperspace TT, OL Illustrious arm, Shelter 90X cart.). Intially I set the VTF to 1.9g; dialed in the overhang with DB protractor; and set the anti-skating bias at what the mft. of the arm said was a good starting point. The VTA looked and sounded a little off; but since the arm was as low as I could set it and it would be a week before I could get the collett machined so I could set the arm lower, I went ahead and tried it. It sounded wonderful. I listened to records all weekend. It tracked everything I played. Floated images out in space like I had never heard. Here's the problem. The next week I had another 0.100" machined off the outside of the collett. In my hurry to set the arm back up, I didn't notice that the wire cradle that holds the anti-skating bias bob weight had moved. The result was too much compensation. This was made apparent by the bad break-up, misstracking in the left channel on the inner tracks of one of my favorite albums. The anti-skating problem was corrected, but the buzzing on the albums played while it was off is still there. Records not played when there was a problem, seem to do OK. Also, the damaged (?) LPs seem to play OK on my old rig (MMF7, Clearaudio Vert. Wood). Both cart. have elliptical stylis. The sound now seems to be less satisfying. Female vocals have a slightly glazed or metalic sound to them and the imaging is not quite what I remember from my first sessions. How much of this is psychological due to my hearing it break-up; are the LPs in question damaged or is it still having problems with the TT setup; I don't know. Any help or suggetions will be appreciated. -JT
john_tracy
jameswei
883 posts
 
I'm not sure whether improperly set anti-skating can cause significant permanent damage to records unless they are played repeatedly. Your stylus pressure of 1.9 grams seems quite standard. I have seen improperly (anti-skate) compensated styli skitter out of a groove and rip across a record with about this much stylus pressure. Of course, if the stylus pressure were high enough, this wouldn't happen, but groove damage becomes more likely.

Your comments seem to suggest that damage to the LPs is a possibility. If so, perhaps the damage occurred only where the Shelter's stylus touched the groove, and this may be a different place than where the Clearaudio stylus touches the groove. I don't really know if the styli actually have different shapes, but if they do, perhaps one is narrower and contacts the groove walls further down, i.e., deeper in the groove, than the other stylus. With this, the Clearaudio is tracking the groove walls at a level that wasn't damaged, while the Shelter would be replaying the groove where it was damaged. Other possibilities exist depending on stylus shape specifics.

I hope you are right about the whole effect being only psychological. Good luck.
patrickamory
193 posts
 
The Shelter should not be super-sensitive to VTA... it sounds like you are having bigger problems with your sound.

Use the HiFiNRR record to dial in the antiskate. Then test it with some real-world records that have big peaks in the inner grooves (most opera and orchestral records should work).

What phono pre are you using, and what loading for the Shelter?

Patrick
twl
3,251 posts
 
This is something that is very hard to diagnose for certain, without being there. I think that you are going to have to make the determination yourself, from your listening and adjusting process.

Even though damage to the record is unlikely, it could have happened. Playing ok with anouther rig and cartridge does not preclude possibility of damage, because the cartridge may trace a different area of the groove, depending on the stylus shape and dimensions, as Jameswei said.

I would also check the azimuth because the machining of the collet could have changed vertical alignment, and re-check all the cartridge alignments. The large VTA movement you did when you re-installed the machined collet could have affected the overhang adjustment slightly.

That sounds like a very nice rig, so it should be awesome sounding. Good luck.
dougdeacon
3,338 posts
 
Not much to add to what the others have said, except to suggest re-cleaning the affected LP's. Perhaps the excessive sidewall pressure ground some dirt into one sidewall. Certainly couldn't hurt to try.

Regarding VTA, I haven't heard the 90X but unlike Patrick we find our 901 to be VERY sensitive. Arm height changes of .04mm or so are clearly audible on the large majority of records. I am building a list and we're re-setting arm height with every change of label or record thickness. Boy that's fun :( Worth it when you find the magic spot though.
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