Crackle in one channel on AT440mlb

Discussion in 'Audio Hardware' started by Al_D, Nov 29, 2015.

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  1. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    I have read this is a problem that can occur with the AT440mla, and I'm certainly getting it on some records with my mlb.

    It's always in the same channel, no matter which record, suggesting a slight misalignment problem.

    I'm having trouble digging up the information that might tell me what this is.

    Has anybody got any suggestions as to how I can improve this, or is there any specific information around in the forum already that I haven't managed to find via the search?

    I'm aware that the microline stylus will sometimes exaggerate problems that other styli will not necessarily bring out at all. This does seem to happen with a surprising number of my records though, and it's always that same channel. Eg, On some of the records, the problem is there with my Shure M97xE too, but not as bad.
     
  2. JimSpark

    JimSpark I haven't got a title

    On those records where your Shure produced crackles, does it always crackle in the exact same passages on your AT, only louder? Or is happening in different passages each time?
     
  3. ceedee

    ceedee Forum Resident

    Location:
    northern england
    bias set wrong or cart not aligned properly i would have said. maybe table not level
     
    Al_D likes this.
  4. jimbutsu

    jimbutsu WATCH YÖUR STEPPE

    It's got to be an AT thing more than other carts though - I have a 150MLX that is usually nice and quiet, but when I do get crackle, it's always on the right channel. I've seen other reports on the 150 as well.
     
  5. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    Yep, same passage. Louder is maybe the wrong word, it's 'worse' though. On the Shure it could be a very light crackle that is undetectable unless you know what you are listening for, on the AT it's a definite crackle.
     
  6. Agitater

    Agitater Forum Resident

    Location:
    Toronto
    If it's happening with both cartridges, and if it's happening only when playing inner grooves on certain LPs, then it's most likely just inner groove distortion. Not much you can do about that.
     
    c-eling likes this.
  7. c-eling

    c-eling They're made of light,We never would have guessed

    Most likely, and with the AT's micro it's picking it up more, I've experienced no IGD on my MLX, check your anti-skate, could be that or just basic groove damage
     
  8. OcdMan

    OcdMan Senior Member

    Location:
    Maryland
    The last time this happened with me (bad/exaggerated crackle always in the same channel), the manufacturer determined the stylus was faulty.
     
    rebellovw likes this.
  9. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    No, it's not IGD, I get excellent results where that is concerned.

    It's at the very start of most of the affected records, often coming in just as the first track starts.

    Example linked below. This is one where I get no hint of the crackle with the Shure. Weirdly other Stiff Records albums I have also exhibit the crackle, but on those it's still partially present with the Shure.

    https://www.dropbox.com/sh/u90z7pvvoqf3h48/AAB-yvY2EwiHY6RHgIalPNtOa?dl=0
     
  10. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    Thanks for the info. It wouldn't explain records where I get the crackle with both carts I suppose.
     
  11. OcdMan

    OcdMan Senior Member

    Location:
    Maryland
    The explanation was that the stylus was riding unevenly in the groove and picking up noise that shouldn't have been picked up at all and, at other times, exaggerating noise that should have been much quieter. The problem went away with the replacement stylus which also sounded better all-around to boot. If it happens on more than a handful of records and it's very pronounced, I'd be concerned about it.
     
    Al_D likes this.
  12. Michael Ries

    Michael Ries Forum Resident

    Location:
    St. Paul, MN
    I've noticed something similar since I've started using the 150mlx. It doesn't seem as frequent as the OP is describing, but I've noticed it on a handful of records that didn't have that issue on my Denon DL-110. The AT cart was aligned by the dealer, and I've only made a couple minor tweaks, but I'm pretty confident it's not an alignment issue.

    I've chalked it up to smaller stylus profile exposing problems I could not hear before. Some records seem to have less surface noise than before, others (though not many) have revealed some extra noise like described above. Since I don't hear any mistracking otherwise and no IGD, I've decided to leave it alone for now. This stylus does seem a bit more fickle than others I've used, but it seems like if I were to adjust for a problem LP, I could introduce problems on the majority that are playing wonderfully.
     
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  13. The FRiNgE

    The FRiNgE Forum Resident

    I do not think the problem is with the stylus. Some members have advised to check the bias (anti-skate) which is fine, but also I do not think that would cause hard crackle (a healthy cartridge/stylus can tolerate zero bias and still sound good.. the bias is not the problem)

    I think the records are bad, a damaged groove. Some of the records may have been played once or more on a record changer, or with a chipped stylus.

    Have you purchased your records new, or used? Are some of the records from one collection from a previous owner?
     
    OcdMan likes this.
  14. OcdMan

    OcdMan Senior Member

    Location:
    Maryland
    I agree that it could definitely be the records. All of those are great questions. It's not an anti-skating issue and it would take a noticeable azimuth tilt to screw up one channel badly, judging by some of the crazy tests I've run over the years. With the crackling problem I had, I already knew the setup was perfect and I knew the records were from multiple sources and most were in excellent condition. So that just left the stylus as the culprit.

    With that said, in the past 16 years that I've been using MicroLine styli, they are almost always the quietest stylus in the groove versus other types even with the average "yard sale" record. I can't help but wonder if what seems to be an increase of complaints/observations about MicroLine styli being 'really good but more noisy than other types' indicates that something has changed with the stylus manufacturing or quality control. Maybe fewer are being rejected because they've relaxed their standards.
     
    Al_D likes this.
  15. jimbutsu

    jimbutsu WATCH YÖUR STEPPE

    I would agree with everything mentioned here except that my experience, like the OP, is that it's always *one* channel. That's the part that drives me nuts. How would one determine if the issue was a faulty stylus? I've had some stuff that's played dead quiet, so it isn't a thing that effects every record.
     
  16. Crackly right had channel at the start of a side? I get this a lot with the 440MLa. I'm pretty sure I've never had it happen with brand new vinyl. After puzzling over this for a few years, my best guess is that the shape of the stylus might just be picking up groove damage, caused by antiskate problems on whatever deck played the disc previously.

    Check the headshell azimuth. If you are able to adjust and it is rotated clockwise (this is off the top of my head, so hope I have this the right way round); this will make the crackle worse, so see if that needs correcting.
     
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  17. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    Some used, some new, various sources.
     
  18. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    I used to have this right-channel static problem at the start of many used LP sides with my M97xE/Jico SAS combo on my AT-LP120 table, but with a Denon DL110 on my Denon DP37F table, it's vanished. I've been thinking it was the notoriously wonky anti-skate on the AT-LP120, and the next time I set it up, I'll see what I might be able to do.
     
  19. JBStephens

    JBStephens I don't "like", "share", "tweet", or CARE. In Memoriam

    Location:
    South Mountain, NC
    I don't know what anybody else hears, but I don't hear an equipment issue, I hear a record cleaning issue.
     
  20. Baron Von Talbot

    Baron Von Talbot Well-Known Member

    This sounds like a bad contact within the cartridge. Sometimes the signal comes through, sometimes not-that is why you hear the crackles.
    You have to replace it I fear. Contact AT if the do repairs and what that costs.
     
  21. Oyster Black Pearl

    Oyster Black Pearl Forum Resident

    Location:
    UK
    My 440mlb is doing the same. I have about 40 hours on mine now, and there's significant crackle on the right channel of the first track of every record I play. I also have a repetition or echo of loud passages in the right channel, Led Zep's "Good Times, Bad Times" is an annoying culprit. None of this occurred with my previous 2m Red cart/Blue stylus combo. Having said that, the 440mlb is more to my taste, otherwise I'm very happy with it.

    Adjusting azimuth has improved matters, but it's still there.

    My records are pristine, I've even re-cleaned some which have been played only once or twice to rule this out. The crackle is still there, even on brand new vinyl.
     
  22. The FRiNgE

    The FRiNgE Forum Resident

    Hello again Al_D, a few thoughts here, and also for member "Oyster Black Pearl", At this point, I do not think there is any mechanical issue with the cartridge/stylus, nor any issue with the records. However you do have the crackle in the right channel only at the outer edge of the record. The causes can be multiple, but here's what I think is happening.

    Premise:
    1) Your AT-440MLA has a line contact stylus. A line contact stylus contacts a long, narrow vertical swath of the groove, so it will track also the upper part of the groove, just keep that thought. The Ortofon Red or Blue are elliptical, which track only the lower half of the groove, no contact with the upper part.

    2) All records (99%) from 1957 to present are pressed with a "groove guard" lip or a ramp to assist automatic changers and manual stylus drops on the record. This is to prevent the stylus from skating off the edge of the record. The ramp is notorious for causing a strong skating force inward, sometimes causing an unstable arm to jump a groove.

    3) All pressed records have a ridge at the very top of the groove. This is caused by the stamper release from the pressed record. This extrusion can sometimes be very close to an adjacent groove, so the narrow margin causes a slight warping into the adjacent groove. The signal of a groove bleeds into the next one, known as pre-echo or post-echo, but ONLY at the upper part of the groove near the flat. (or near the surface of the record) The mastering engineer must allow enough margin between the grooves to minimize or prevent pre-echo/ post echo. The deeper parts of the groove are not affected by the adjacent groove.


    The result:
    1) The AT 440MLA is tracking in part, the upper section of the groove, the part most prone to pre-echo/ post-echo. It is also the upper part of the groove that is most susceptible to any micro-surface scratches, and "surface noise". The line contact can reduce surface noise on certain records, but increase it on others. The Ortofon Blue is an elliptical, so it tracks only the deeper part of the groove, and entirely does not contact the upper part at all. So, the Ortofon will not pick up any pre-echo/ post-echo distortions in the groove, or far less of it. These are not stylus issues, just the pluses and minuses of using a certain stylus shape

    2) The reason (I think) you are getting echo only in the right channel is due to the ramp on the record. The ramp introduces azimuth error. The cartridge may be set up perfectly, but you'll always have errors at the outer edge. Because of the record incline at the outer edge, the area of stylus contact becomes unequal on the left and right sides, so the sylus may come into excessive contact on the upper groove edge on one side. The line contact is more sensitive to this error vs an elliptical. This is not a stylus defect nor a record defect, since this is how records have been pressed for decades. The pressing with just an outer "groove guard" lip is superior to the pressing that is inclined (a ramp).... although some pressings with only the lip can also be inclined slightly at the outer edge.

    3) The crackle likewise on the rt channel comes from azimuth error at the outer edge (again caused by the incline or ramp of the record surface) Once again, since the line contact stylus normally tracks very nearly the entire vertical swath of the groove, it tracks also very near the upper section. Any azimuth error can perturb this to the point of mistracking, and/or tracking at the very top of the groove, where there is the extrusion, (or ridge) and the rougher part of the groove wall. This will usually occur more in one channel than the other. At the outer part of an LP, the noise would occur in the right channel. Ortofon Blue elliptical stylus is less affected by azimuth error. The stylus does not track the upper groove wall at all, so these symptoms do not appear.
    _________________________________________________________________________________________________________

    You may want to check the azimuth of your stylus just to make sure. If there is even the slightest lean, just a small correction could improve your play quality immensely. Other than that, I do not believe at this point that you have any defects causing the noise and pre-echo. It's the occasional something that has to be lived with when using a line contact type stylus. Your cartridge may be set up perfectly, and still you'll get the occasional crackle or pre-echo. It's a vinyl thing.

    My thoughts are based on 30+ years experience, plus a few assumptions made on this enigmatic problem, (I have personally not experienced this problem on one channel, however favor a hyper-elliptical stylus)
    rock on,
    Steve VK
     
    Last edited: Jan 17, 2016
    Rekkerds, dbsea, tin ears and 4 others like this.
  23. jimbutsu

    jimbutsu WATCH YÖUR STEPPE

    Thanks for all that info, Steve - this is really interesting. Do you think that the (presumably proprietary) profile of the AT Microline stylus is why it seems to get talked about with their carts more than others?
     
  24. Oyster Black Pearl

    Oyster Black Pearl Forum Resident

    Location:
    UK
    Seconded, what a brilliant post, thank you!
     
  25. Al_D

    Al_D Forum Resident Thread Starter

    Location:
    Bristol, UK
    Thanks for sharing the knowledge, this has been very helpful in understanding what is happening. It seems to happen a lot on records released by Stiff Records, and they do seem to be pressed with a slight incline at the edge so this is a good explanation. However, the crackle can persist for a few tracks, getting better towards the middle of a side. I guess a lot of it is just the increased contact with the upper groove picking up small surface defects.
     
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