I'm still getting inner groove distortion (among other problems)

Discussion in 'Audio Hardware' started by SurrealCereal, May 14, 2019.

  1. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    I've posted a thread about this before and alluded to it in another, but I've had some newer developments so I thought I'd just start a new thread. Like the title says, I've been experiencing inner groove distortion on my turntable, including brand new records. In addition to distortion, the inner grooves have also been more prone to skipping and locking into a single groove perpetually. Once the needle gets into the dead wax, I usually only have a couple seconds before it jumps back into the last few seconds of music. Also, I've noticed that when I drop the needle into the outer dead wax/blank groove (I don't know what it's called) it will usually skid over all those grooves and occasionally some of the first few seconds of music. A lot of these problems are more recent developments, so I fear whatever is wrong is getting worse.

    In trying to combat this, I've replaced my cartridge, adjusted the anti-skate (though I'm not really sure what I'm doing with it), and used one of those alignment protractors (I'm not 100% sure I'm using that correctly either).

    My turntable is a TEAC TN-300 and my cartridge is an Audio Technica AT95E.
     
  2. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    RE: skipping at the lead-in groove, that suggests non-working anti-skate or a cueing mechanism problem.

    RE: locking at the inner groove, that could be a dirty stylus, or a turntable that is not properly leveled, or a badly pressed record. Records with bubble warps near the center or odd dishing warps can also cause that problem.

    Sounds like you've got multiple things going on.

    The first thing I would do is get the turntable on a proper rack and get it leveled. You want to level both the plinth and platter, check multiple positions. I would use some kind of torpedo level for this. If the feet are adjustable level that way. If not, use business cards to get the TT leveled.

    The next thing I would do is check to make sure the anti-skate is working at all. To do this, you get a blank CD or laser disc and crank up the antiskate until the stylus stays put. Does it work or does it continue to skate toward the center? Now, to be clear I don't suggest setting your anti-skate with this way. It's merely a test to make sure the anti-skate works.

    Look up Peter Ledermann's videos on YouTube about setting anti-skate and do it that way - at least that is the way I prefer. There are many different philosophies on how to set anti-skate BTW.

    Next thing will be to check your VTF. If you do not have a digital scale, get one. They are cheap, usually no more than $15. Calibrate the scale and set at the manufacturer's recommended value.

    Re: the stylus, clean with Blutak or a Zerodust type cleaner or a small stylus brush. You can use AT liquid cleaner but I don't recommend using it often. You also want to make sure you only clean the tip and don't get the fluid up the cantilever and into the suspension.

    Re: alignment, learn how to use the Conrad Hoffman program and align for Stevenson using an accurately printed arc protractor.

    Now after all that is done, observe tracking behavior on a flat, well pressed record. Are you still experiencing skipping at the lead-in groove? If so it is likely a problem with the turntable's cueing mechanism or something and it might be time to make a warranty claim if it's not something that can be easily fixed. Watch out for the cue lift not going down when you lower the stylus on the lead in groove. If the arm is smacking the cue lift because it's not lowering properly near the tonearm pivot, that's a problem.

    IGD should be dealt with after everything else listed above. Here is the hard truth: you will never be able to fully eliminate IGD with that cartridge on all records.
     
    Last edited: May 14, 2019
    Shawn, Aftermath, Kyhl and 4 others like this.
  3. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    This. Hes right about pretty much everything here.
    Level the table, check anti skate and set it so that the arm only moves very slowly in on deadwax areas or a CD, re align and try again.
    But remember, IGD will always be audible on that cart stylus.
     
  4. Raunchnroll

    Raunchnroll Forum Resident

    Location:
    Seattle
    Thats good tracking cartridge in that range. It sounds like a TT set up issue. The above advice is a good start. Gotta emphasize the VTF though as much as the anti-skate. They all affect each other. As far as IGD, once its all running fine, IGD should be very minor with that cartridge. Its not a $800 cartridge so don't fret it. And one last thing, view the stylus and cantilever to the cartridge/headshell. The stylus/cantilever should be perpendicluar and centered.
     
    Last edited: May 14, 2019
    SurrealCereal likes this.
  5. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    Thank you for the detailed reply. I will try to follow your advice.
     
    zombiemodernist and patient_ot like this.
  6. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    Let us know how it goes and ask about anything.
     
    SurrealCereal likes this.
  7. Thorensman

    Thorensman Forum Resident

    Try lowering the arm by hand after releasing cueing device

    I suspect tha skipping at start will no longer be a problem
    You must have correct VTF
    Set bias as per manufacturers instruction.
    You can check it with a test record.
    Stick to band1.( trust me,)
    Now with motor off, arm lowered into groove. You should have a clearance between underside of arm
    And cueing device
    If cueing action is slow this will definately cause one of your problems
    Cartridge orientation in headshellwill minimise inner groove
    Dirty records usually cause of distortio

    If problems persist, put arm in static balance position
    This is done by sliding back counterweight till arm floats
    Switch off bias.
    Now with turntable LEVEL
    Arm shoulf dip when gently tapped and returm to starting positio
    Arm should not swing in or out
    When tapped in or out
    It is assumed that platter is level
     
  8. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    My plinth seems to be pretty much level, but I’m not so sure about the platter. The bubble stays within the lines anywhere I put the level on the platter, but in some spots it’s dead center, whereas in others it falls closer to one line. Is there something I should do about this or is the difference negligible?

    I tried testing my anti-skate with a CD, but the needle stayed put no matter what I set the anti-skate dial to. Does this mean my anti-skate is definitely broken or should I go buy a laserdisc from a thrift store to try it on a larger area?
     
  9. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    1) Try leveling with playing cards or business cards. What kind of level are you using for this? It could be you need to level it better or it could be the platter is manufactured poorly.

    2) You can buy a laser disc if you want for peace of mind. If the arm fails to skate at all toward the center with the anti-skate dial set at zero, something is very wrong.

    How long have you had this turntable? Is returning it an option? You still have some things to try but this is starting to sound like a defective unit to me.
     
    Shawn likes this.
  10. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    warped platter? Shouldnt be too bad if the plinth is leveled though.

    Anti skate is working, but it seems its too strong perhaps? It should allow the arm to skate inwards if its low enough.
     
  11. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    I’m using a 24 inch spirit level. It’s probably a bit too big for my purposes but I don’t think I have anything smaller. I was still able to fit it on both plinth and platter at multiple angles without anything getting in the way.

    I gave the CD trick another try and it still doesn’t appear to be moving at all. I did notice that when I turn the dial from zero to three while the CD is spinning it moves the needle slightly closer to the outer rim of the CD. I don’t know if that means anything, but it at least suggests my anti-skate is doing something.

    I’ve had it for a couple years now so I doubt returning it is an option
     
  12. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    I just noticed that my platter bobs up and down at some points when it spins. I remember now that it’s done that ever since I got it, but I had forgotten about it since I didn’t know that was a bad thing.
     
  13. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    Well the anti skate is working somewhat at least. My guess is that its spring based and just has the spring way too tight.
     
  14. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    Then thats probably why you cant level it perfectly. Hard to say how much of a problem that is without seeing how bad it is first hand however.
     
  15. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    Right, if the anti-skate being cranked up causes the stylus to move outwards then that means turning it up is doing something - increasing the anti-skate. However, with the anti-skate turned to zero that would mean that most styli are going to skate toward the spindle when lowered, even if the platter is turned off and not moving. So it would maybe appear that the spring inside the anti-skate dial mechanism is too strong. If you wanted to, you could try replacing it with a different spring that allows a different range of adjustment. Just be aware that depending on how the arm is made, it may have not been designed to be disassembled after it was put together.
     
  16. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    That sounds like a warped platter. If the warp is bad enough it could cause issues like you've described upthread. You can try gently removing and reseating the platter to see if that helps - it's possible it may not be seated correctly but a warped platter is also possible. FWIW warped platters are fairly common on Hanpin/Ya Horng TTs.
     
  17. SurrealCereal

    SurrealCereal Forum Resident Thread Starter

    I took the platter off and inspected it. I didn’t notice any signs of being warped, especially not to the degree that it bobs when in use. Is a warped platter usually something you can see or detect with a level and ruler? I put it back in place and it’s still bobbing in the same way it was before
     
  18. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    You would only be able to see it while it is spinning. If the platter checks out as being flat and true when inspected multiple ways (the same way you would check or car or bicycle rim for runout), check the spindle and bearing housing that the platter sits on. That could be bent or not straight. Then there is the matter of the precision of the hole drilled in the platter and how the spindle fits there. If it is off or made to sloppy tolerances you may notice some weird bobbing or shifting when the platter spins.
     

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