Inner Groove Distortion

Discussion in 'Audio Hardware' started by Spitfire, May 18, 2007.

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  1. Spitfire

    Spitfire Senior Member Thread Starter

    Location:
    Pacific Northwest
    Can somebody give me a quick explanation about inner groove distortion? How come some records seem to have quite a bit and others don't have any (at least none that I notice)? Is this record dependent or do some turntable/cartridge combinations handle it better? Thanks
     
    Fleet Fox likes this.
  2. Onward

    Onward Forum Resident

    Location:
    Oslo, Norway
    Kevin Gray has a pretty good explanation over at RTI:

    http://www.recordtech.com/prodsounds.htm

    So in short it's a combination of treble content in the mix, instruments and voices used, record lenght and the shape of your stylus (assuming your turntable is in proper alignment). And possibly some other factors that I have overlooked :)
     
    Heckto35 and Still Life like this.
  3. TONEPUB

    TONEPUB Forum Resident

    Location:
    Portland, Oregon
    Honestly, I think it's a mixture of both...

    Sorry to be so vague. A lot does depend on your arm, cartridge
    and how well they are setup too.
     
  4. MMM

    MMM Forum Hall Of Fame

    Location:
    Lodi, New Jersey
    Hyperelliptical/MicroRidge and other long, narrow styli should help a lot.

    Once I tweaked my Rega 3 w/V15 VxMR just so, it's virtually eliminated. Not even on Steve's records (some of which are VERY hard to track/trace correctly, cut no compromise as they are) or hot 12" singles. I bet most people with this cartridge, or the Type V, have similar experiences. I plan to be buried with my V15... :love:
     
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  5. DrJ

    DrJ Senior Member

    Location:
    Davis, CA, USA
    Yep Martin - totally agree. Love the V15VxMR, it's a remarkable tracker. Even on my humble Technics table, no inner groove mistracking. I need to pick up a second one for backup, too bad they're so expensive on the 'Bay. Wonder if, with the vinyl resurgence, we'll ever see Shure start this series up again (highly doubt it but we can dream).
     
  6. Tubeman

    Tubeman New Member In Memoriam

    Location:
    Texas
    Here's a post I got from another site.
     
  7. JoelDF

    JoelDF Senior Member

    Location:
    Prairieville, LA
    Not to question Kevin's expertise, but I always thought that in the stereo record groove one channel is the side-to-side movement and the other is the up-and-down movement - thus translated by the needle up the shaft with coils on either side (sent to one set of wires) and above and below (sent to the other set of wires) the other end of the shaft inside the cartridge.
     
  8. DrJ

    DrJ Senior Member

    Location:
    Davis, CA, USA
    JoelDF: I'm no expert (and I'm definitely not Kevin!) but I think what you're thinking of are a very small subset of older records (78s) that had vertical (as opposed to lateral) groove information; go to this web site and scroll down to the "Groove Type" section for an explanation:

    http://www.78rpm.com/rescat/tech_info_page.htm
     
  9. TONEPUB

    TONEPUB Forum Resident

    Location:
    Portland, Oregon
    Me Im going for the OM40, which was reported here as the only accurate cartridge on Earth...

    I read it so it must be true!
     
    Heckto35 likes this.
  10. MikeyH

    MikeyH Stamper King

    Location:
    Berkeley, CA
    As you get nearer the center of the record, the groove velocity reduces (in fact the linear speed of the groove is about 1/3 of the speed in the centre that it is at the rim). It's like playing the start of your record at 15ips on tape and slowing it down to 3 3/4 by the end of the side. Basic frequency response is affected, due to the cut waveforms becoming shorter. In the limit, high frequencies become too small to move the stylus. A narrow stylus profile helps (though not as much as you'd think) as does accurate set-up (any error is more significant at the inner radius). Any friction in the arm will show more at the inner grooves too. Mechanical 'semi auto' features can cause a lot of problems.

    Many 'classic' good sounding albums are programmed to have 'less challenging' tracks at the ends of sides. The playing field is more level with tapes and CD.

    As your stylus wears, it picks up more dirt (and vinyl groove material..:yikes: ) as it traverses the side, and this just adds to the problem. I always regard increasing end of side distortions as an indication that it's that replacement time again.
     
    2xUeL likes this.
  11. lukpac

    lukpac Senior Member

    Location:
    Milwaukee, WI
    Are you actually getting one, or just joking?
     
  12. Vinophile

    Vinophile Active Member

    Location:
    Cambridge, UK

    Probably a joke on nin but I'm getting one after I buy my SET :goodie:
     
  13. John Carsell

    John Carsell Forum Resident

    Location:
    Northwest Illinois
    Agreed.

    Try the Mr. Blue Sky test from a good vinyl copy of ELO's Out Of The Blue.

    Mr. Blue Sky is the last track on side 3 and if somethings not right you'll hit inner groove distortion at the half way point in the song. It's also very obvious.

    I had this problem with the Shure M97xe and when I went and changed it to the Audio Technice AT 440 MLa and got it all aligned and everything the inner groove distortion disappeared.

    However if a record gets one too many plays with something outta whack the inner groove distortion most likely will be there for good.
     
  14. nin

    nin Forum Resident

    Location:
    Sweden

    I'm still breaking in my OM40 but already it have DESTROYED my old MC-10 Supreme cartridge. But I need some torture test records to see how good it tracks them. Any suggestions?

    Edit: Btw, the guy that told me about the OM40 they did here in Sweden is the guy behind these speakers: http://blog.stereophile.com/he2007/051307Sjfon/
     
    Heckto35 likes this.
  15. nin

    nin Forum Resident

    Location:
    Sweden
    Don't have it (have no classical music at all).
     
  16. TONEPUB

    TONEPUB Forum Resident

    Location:
    Portland, Oregon
    Well, when I was cleaning up my office I found an OM-10 still in a box, don't even remember where it's from. So, I'm going to put it on my SL-1200 clone (the AT version) that I use to play 78's and get an OM40 stylus for it and see just how well it does.

    With the Shure V15 gone, I'm looking at a number of decently priced MM carts to suggest to our readers.

    Used to have Ortofons in the old days and they were quite good, so who knows, maybe I'm missing the boat?
     
  17. Onward

    Onward Forum Resident

    Location:
    Oslo, Norway
    Nirvana - Nevermind ,universal willem makkee 320-version, polly and something in the way are good tests for vocal sibliance.

    The DSOTM 30th anniversary is a tough one too...
     
  18. nin

    nin Forum Resident

    Location:
    Sweden
    I have the DSOTM 30th, I will try it next week!
     
  19. shane

    shane Active Member

    Location:
    Oswego, NY, USA
    I've heard the term before but never really experienced it until just now. I'm sitting here listening to the New Pornographers "Electric Version" and it started sounding real distorted. I look at the record and it ws indeed towards the inner groove. What causes this? Is it pressing related or a cartridge issue? If its the latter what can I do to prevent or fix it? Thanks.

    Shane
     
  20. paulw

    paulw New Member

    Distortion with pivoting tonearms is a fact of life (or geometry) hence the importance of set-up to minimise this. The only way to negate this distortion would be with a linear tracking arm or supposedly the likes of the RS Labs RS-A1 arm (I’d really, really like to give one of these a try) with its swivelling headshell. To reduce this inherent distortion the cartridge position (sometime known as overhang) is set so that its arc across the record is as close to a straight line as possible (Tangential segment??) which of course in reality, is a physical impossibility. That’s obviously a very simplified statement so don’t take me to task over it. This is why 12” tonearms have reduced distortion, their arc will be closer to optimum, indeed the longer the arm the better for this (but worse for other factors). Now, once you’ve set-up your turntable & cartridge as per manufacturers guidance you should have minimal distortion. Again, it is perhaps worth pointing out that the alignment protractors you get supplied with any pivoting arm will be a compromise, as in most instances they’ve taken one of the three main principles;

    Baerwald: - The distortion at the beginning, the middle (where it’s high) and the end of the record must be equal.
    Loefgren: - Alignment must minimize the distortion across the record.
    Stevenson: - Distortion is more important at the end of the record so let’s minimize it by assuming a null point at the end of the record, i.e. at 60.325 mm (IEC standard end of the record).

    Stylus tip wear will also usually be more evident at the inner grooves as will incorrect bias on highly modulated tracks.

    Paul
     
  21. av-geek

    av-geek New Member

    Location:
    Richmond, VA
    Distortion on the inner tracks also comes from the simple fact that there is significantly less velocity under the stylus on as the tone arm tracks towards the center. Because more vinyl is passing under the stylus on the outer tracks of a record, higher frequencies are recorded with much broader deflection. In the inner tracks however, the higher frequency waves are recorded much closer together where they are subject to more wear through playings.

    The advantage to inner grooves however is that because there is less velocity under the stylus, surface noise is less. In the sixties, most rock groups would record their best songs on the outer most grooves of the record.
     
  22. Graham Start

    Graham Start Forum Resident

    Location:
    Toronto, Canada
    I'm surprised that nobody mentioned it yet, but using a cartridge with a fineline or microline stylus will greatly reduce inner groove distortion.
     
    Heckto35 likes this.
  23. william shears

    william shears Forum Resident

    Location:
    new zealand
    You got it! $89.00 will buy you the Audio Technica A440MLa. Say goodbye to inner groove distortion, say hello to clean, crisp groove tracking.
     
    Heckto35 likes this.
  24. Buzzcat

    Buzzcat Forum Resident

    Location:
    Madison, WI
    And $1600 will get you a uni-pivot VPI Scout. Poof! IGD gone!
     
  25. paulw

    paulw New Member

    I'd argue that neither of the above is correct - the better the tip the more prone it is for showing alignment issues, get an old style tip like that sported by the Denon 103 (spherical) and you can be more sloppy in your set-up. Unipivots, tend to tame both frequency extremes, by their design nature, so again don't highlight the problems so much.

    Best thing is just to get the set-up right.

    Paul
     
    AmericanHIFI likes this.
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