Audio-Technica AT-LP120 Preamp Removal (Detailed Instructions Video)

Discussion in 'Audio Hardware' started by FrankieP, May 20, 2013.

  1. crdemers72

    crdemers72 New Member

    Location:
    Madison, WI
    Yep, you are right, the cartridge needs to go just a couple degrees toward center and then it lines up on the protractor like a champ. I actually thought the Shure was more dynamic, had less tinny highs and rounded out the bass for me (over the stock 95). I guess the fact I do process it through my surround sound amp has an effect but I also process CDs through the same effect on the amp. Even in 'pure' mode, records sound better (in general) on that cartridge than the stock cart or a CD. I bet you'll have great luck with the 440MLb but at $199 from WalMart, that's a bit of a reach for me right now!

    Wish I still had my Maiden records, though. Where's the jealous emoticon? :)

    - Colin
     
  2. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    If you check the math he included the cost of the turntable in there. So $750. And you shouldn't include the cost of the pre amp, or stylus brush and record brush, since other set ups you'd need that as well.
     
  3. MikeInFla

    MikeInFla Forum Resident

    Location:
    Panama City, FL
    @Ben Adams have you seen this video that mentions your blog?

     
  4. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    No! I'll have to check that out when I'm off work! Thanks for bringing it to my attention.
     
    MikeInFla likes this.
  5. adm62

    adm62 Forum Resident

    Location:
    Toronto, Canada
    I stand corrected.
     
  6. DarkAudit

    DarkAudit Well-Known Member

    About the only thing unique to the LP120 is the $30 counterweight upgrade. About everything else can be moved on to the next table. Like maybe if you happen to be hanging around your favorite electronics repair shop and just happen to notice an SL-1200 sitting in the display case. And look! It's payday AND all the bills for the month were taken care of already. Merry Christmas to you! :D

    Yeah, that happened. I have an LP120 I tweaked per Ben's blog post and lost the urgency to go out and find a 1200. The one i have just fell into my lap. The 120 is now part of the backup system.
     
  7. ltusler

    ltusler New Member

    Location:
    Minneapolis
    Has anyone else simply added another set of RCA cables? I just soldered the set at the same point on the main board that the wires from the tone arm appear and I use a external phono amp. So now it has 3 ways to connect it. Its very sensitive, if you blow on the needle, you can hear that out of the speakers.
     
  8. Michele Magnardini

    Michele Magnardini New Member

    Location:
    Reading
    I've decided to remove the bloody pre-amp board this morning, after using the LP-120 in phono mode with a humble ArtDJ (that I love btw) for about 2 years.
    That circuitry can really colour the sound even if bypassed! I'm flabbergasted by how more lively and detailed the TT sounds, even with my modest setup.
    Word of advice, proper grounding is a must if you attempt this mod.
     
    Jam757 and DarkAudit like this.
  9. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    OK ready to do this. Need to make sure I have all the tools first. Looks like I need a phillips head screw driver, wire cutters (maybe a kind that'll strip wires too?), small wire caps, and electrical tape.

    One thing I am not clear on - where can I get the cap for the ground wire? Or can I just strip the end of that and wrap it around the external preamp ground screw?
     
  10. illadvised

    illadvised New Member

    Location:
    San Francisco, CA
    Not sure how active this comment section still is, but I just performed this mod last night and the audio is coming through really faint and scratchy. Rewatching the vid again now, I realized I forgot to connect the RCA ground to the channel wire ground. Would this cause aforementioned faint/scratchy sound? Hoping to take another crack at it and rectify it tonight.

    For clarification, do I connect both RCA ground wires (one from red, one from white) to the channel wire ground (twist capping 3 wires in total)?

    Thanks!
     
  11. illadvised

    illadvised New Member

    Location:
    San Francisco, CA
    You will need an extra wire for the ground, long enough to run out of the back and connect to your preamp and/or receiver with a phono stage. I just used some spare speaker wire. Also for the end of the ground wire you can do what you suggested, but I'd recommend a small spade like the one used in the vid which you can buy from any hardware store. While you're there you should also pick up a crimper (if you don't have one already) which you'll need to attach the spade to the stripped end.
     
    guidedbyvoices likes this.
  12. illadvised

    illadvised New Member

    Location:
    San Francisco, CA
    Please disregard. Figured it out as soon as I got home from work. Working like a champ. Thanks again for putting this together, FrankieP!
     
    Ben Adams likes this.
  13. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    I'm goin in
     
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  14. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Done and up and running!!!!

    Took two hours to do, thirty minutes to put it all back together. And no hum, sound is working. Now for some critical listening.

    Took two hours and that's with me seriously confused as some of my wires inside looked a little different, and the small grey caps I had, smallest my hardware store had, were still too small to tie the rca to the board. Those are some very thin wires. I used electrical tape instead of the caps.

    What confused me was there are two different sets of ground wires that really threw me.
    The rca had red plus ground and white plus ground. Red to red, white to white, and two unsleeved grounds from the rca to the one ground

    That Rca ground wire is completely separate from the ground wire needed to go from the cut ground wire on the circle hook out the back to the preamp. I at first was trying to tie the ground for the preamp to the rca ground, which would've been four grounds tied together. Once I figured out it was separate I was good to go. crimping the spade connector to the preamp side of the ground wire was simple

    Thanks so much to this thread and the original post with the how to video. It was all super helpful. I'm very inexperienced with this kind of work so it was a challenge but doable.

    In first pic the preamp is the green board at top.

    [​IMG]
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    [​IMG]
     
  15. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    One other thing that confused me - there was a set of skinny wires from the bigger green board that end in a little plug into the internal preamp. After I unplugged it and removed the preamp, I wasn't sure where it should go. Apparently it goes nowhere. No idea what it did before but doesn't seem to be affecting anything
     
  16. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    Well? How does it sound? :D
     
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  17. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Trying a few things out. I think its a little brighter. Possibly less turntable rumble. I noticed on my Beatles Revolver mono reissue where before I thought maybe they mastered it to avoid sibilance, now the s's come through clearer. It was one of the few albums I had an issue with s's since getting an AT440mlb cart and use that alignment. Not that they were distorted but like they weren't there. I played it before the surgery to be sure. Weird.

    Not sure yet overall, still early. My gut says if bypassing the internal and using the Schiit Mani was an 8 of 10 improvement, this is more subtle but noticeable, like a 3 out of 10.

    I'll check in after I've had time to try more stuff out.
     
  18. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    After listening to about ten records of different styles and genres, I'll say this is about a 4 out of 10 improvement to sound. The preamp alone, a good cart, good speakers were dramatic improvements. This is not as dramatic but I feel like it's a bit cleaner and defined, a little brighter.

    Overall I recommend the removal of the internal preamp. It's a cheap DIY improvement and if you're doing things like paying $30 for a heavy counterweight or $25 for a mat, then this is a tweak worth doing.
     
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  19. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Since I removed the preamp, I feel like static pops are much more pronounced than before. Anyone else have that issue? Now it's possible since it got hotter and AC running, plus my dry climate, that it's just been a static-y time, but the pops are louder than the music at times.

    I do have a rubber mat, spin clean my records and use a carbon fiber brush, and happens on new clean vinyl

    Any ideas?
     
    Last edited: Jun 28, 2017
  20. draden1

    draden1 New Member

    Location:
    des moines, ia
    I just removed the preamp a few weeks ago and now I'm noticing more sibilants during playback. I have an at440mlb and while listening before when bypassing the internal preamp the sibilants weren't this pronounced. Not sure if this is normal for everyone or what? I would agree with a lot of statements on here that after the removal the highs are a bit clearer and that background noise is reduced quite a bit.

    Overall, I'm glad I did the mod but would like to hear other people's impressions if they've noticed the "s - sh - see" being more up front.
     
  21. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    I have the same cart, no issues with sibillance. I do notice static pops are much louder than before, that's my only negative from the mod. Recheck the alignment of your cart maybe?
     
  22. draden1

    draden1 New Member

    Location:
    des moines, ia
    Thanks for the reply. The funny thing is that I didn't have such forwardness with sibilance before the mod. The first thing on troubleshooting this was to realign the cart, I used the Technics overhang gauge and then used the protractor from the AT website they recommend for this TT. Sibilance is not on every record or even every song from records that have it on a few songs. I'm thinking that I just have to get used to the differences between records and the mod has now made things even clearer than they were.
     
  23. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Not sure which protractor AT recommends but see this site from @Ben Adams

    Scouring the Bins: Tweaking an Audio-Technica AT-LP120 Turntable

    I've had zero issues with sybilance using it. My cart sits almost all the way back and tilted slightly in
     
    Ben Adams likes this.
  24. JohnO

    JohnO Forum Resident

    Location:
    Washington, DC
    The cart might look visually perfectly aligned, but you can go a little further. Loosen one screw and turn the cart in, the front of the cart, toward the spindle about 1/8 mm - the tiniest little bit. And listen. Do the same, turn the cart about 1/8mm away from original, (or now 2/8mm away). And listen. If one way sounds better regarding IGD or anything else, that is your new normal. Then you can repeat or experiment with even smaller movements.
    You have been aligning the cart body, and that's good, but you're doing it visually. But, the cantilever could be a few microns tilted, such that you can't see it. And on the cantilever, the stylus tip point itself could be a few microns off. Narrowing it down by ear, or using a $25,000 alignment machine, gets it better.
    You do not have to expect or accept that even a $50 cart must have sibilance, and yours is better.
     
  25. marcob1963

    marcob1963 Forum Resident

    Welcome to the Club. I've haven't had any increased clicks & pops since removal. Maybe you've got static issues. I know many are particular about the labels on records, however if you dunk your records in distilled water and let them dry, that will kill static for a while. Labels won't be damaged unless they have air bubbles. Also, your records may require a more thorough cleaning now that your TT is more revealing or it could be an alignment issue.

    I'm using an AT440mla, someone has posted a link to Ben Adam's blog a few comments above. I recommend the use of the Protractor that Ben suggests and dial in the numbers he recommends. That's how I aligned my cart and sibilance has been almost non existent.
     
    Ben Adams likes this.

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