Upgrading your AT-LP120 turntable

Discussion in 'Audio Hardware' started by Ben Adams, May 30, 2012.

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  1. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    Last autumn, I purchased an Audio-Technica AT-LP120 turntable based off the great online reviews I read. Since then I have been in a battle to get it to sound its best. I'd like to pass on a few things I've learned.

    1) Replace the felt slip mat with a rubber mat. This shouldn't be too hard, even though rubber mats aren't something you can just find at a local shop anymore. They seem ridiculously expensive online, but check your local thrift shops for used turntables. Here in Phoenix, TT's seem to go for about $10 at Goodwill. Find one with a decent thickness rubber mat, and you're all set.

    2) When replacing a cartridge, use the Technics Overhang Gauge to measure your overhang. The AT-LP120 uses the same geometry as Technics turntables with S-shaped tonearms. DO NOT USE BAERWALD GEOMETRY OR A MOFI GEODISC. They will result in improper cartridge alignment. Instead, use the Technics Arc protractor available here. (You'll have to scroll down a little ways to find it.)\

    3) Finally . . . remove the built-in preamp, as per this video. Yes, you heard right. Open up the bottom of your TT and yank that sucker out and then utilize an external phono stage, either a dedicated pre-amp or a receiver/amplifier with phono input. The built-in preamp is a piece of garbage. If you're using it, it adds an unpleasant digital tone to the playback, almost a graininess. Believe it or not, it also accentuates surface noise and sibilance!!! If you bypass it using the switch on the back of your turntable, there are still capacitors in the signal path which will make it sound dark and closed-in when their capacitance is added to that of your external pre-amp.

    I removed the internal pre-amp from my AT-LP120 last week and the sound quality increase was immediately noticible and significant. If you go to the Needledrop thread, you can find this post I made with several examples of the same piece of music which should convince you.

    Hopefully this post will save current and future AT-LP120 owners the months of constant and fruitless readjustment I spent with mine. I am very, very happy with this turntable now. :cheers:
     
  2. JBStephens

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

    Location:
    South Mountain, NC
    Pay a little more and get a good aftermarket Sorbothane. This will help to dampen the ringing of that flyweight platter. And don't forget to upgrade the interconnects while you're in there. I've also found that it needs the antiskate set a little higher than the tracking force. The PL120 is very versatile, and with a little aftermarket help, can actually be good.
     
  3. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    Good point on the sorbothane, because that platter can ring . . . but I wanted to clue people in on my secret for finding rubber mats cheaply. :)

    Thanks for the tip on the antiskate. That's so non-intuitive that I hadn't tried it.
     
  4. RPhelps

    RPhelps Forum Resident

    Location:
    Athens, GA
    AT-LP120

    1) Replace the felt slip mat with a rubber mat. This shouldn't be too hard, even though rubber mats aren't something you can just find at a local shop anymore. They seem ridiculously expensive online, but check your local thrift shops for used turntables. Here in Phoenix, TT's seem to go for about $10 at Goodwill. Find one with a decent thickness rubber mat, and you're all set.

    I will definitely try this.

    2) When replacing a cartridge, use the Technics Overhang Gauge to measure your overhang. The AT-LP120 uses the same geometry as Technics turntables with S-shaped tonearms. DO NOT USE BAERWALD GEOMETRY OR A MOFI GEODISC. They will result in improper cartridge alignment. Instead, use the Technics Arc protractor available here. (You'll have to scroll down a little ways to find it.)\

    I will look for one of these techniques overhang gauges.

    3) Finally . . . remove the built-in preamp, as per this video. Yes, you heard right. Open up the bottom of your TT and yank that sucker out and then utilize an external phono stage, either a dedicated pre-amp or a receiver/amplifier with phono input. The built-in preamp is a piece of garbage. If you're using it, it adds an unpleasant digital tone to the playback, almost a graininess. Believe it or not, it also accentuates surface noise and sibilance!!! If you bypass it using the switch on the back of your turntable, there are still capacitors in the signal path which will make it sound dark and closed-in when their capacitance is added to that of your external pre-amp.

    I won't be removing my pre-amp because I might want to resell this table and looking at that video tells me once you remove this it would be most difficult to replace it. I do use a dedicated pre-amp in place of the built in one though.

    thanks for all :righton:
     
  5. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    You'll need to order one online. I included a clickable link in my initial post. They're $6 plus shipping, and it was the single best investment I've made for this turntable.

    Just FYI, this is the single change that will give you the best sound. Even though you're using an external preamp, the signal from the AT-LP120's tonearm is still running through its pre-amp circuit board before it hits your pre-amp, and the additional capacitance is adversely affecting the signal -- so that what you're getting through your dedicated pre-amp is darker and more congested. I was shocked by the difference once the interior pre-amp was removed, I really was.

    However, if you need to sell it, I understand why you wouldn't want to perform this surgery! :) I plan on passing this TT along to one of my brothers when I'm done with it, so that wasn't a concern.
     
  6. action pact

    action pact Music Omnivore

    When I had an AT-PL120, I replaced the mat with a DIY cork mat.
     
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  7. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    How did you feel it improved the sound?
     
  8. action pact

    action pact Music Omnivore

    Mainly I found that it tightened up and enhanced the bass, which is one of the sonic weak points of the AT-PL120. At that time, my stereo wasn't particularly revealing, so I can't comment on it with any more authority.
     
  9. motorcitydave

    motorcitydave Enlightened Rogue In Memoriam

    Location:
    Las Vegas, NV, USA
    Good info there, Ben.
     
  10. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    Thanks. :cheers: I just don't want anyone else bashing their head against the wall like I did . . . especially regarding the cartridge alignment. It took me MONTHS to find the info that this TT is a close enough copy of the Technics 1200 that the Technics Overhang Gauge is what's needed. In the meantime, I actually paid a local shop to align my cartridges and they wound up sounding worse than they did before. :realmad: Using the Technics Overhang Gauge, I found that the carts should be set back quite a way in the headshell. Baerwald alignment had the carts almost all the way at the front of the headshells. A pretty major difference in overhang. . . .
     
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  11. Robin L

    Robin L Musical Omnivore

    Location:
    Fresno, California
    I suspect a sorbothane mat would work in a similar fashion.

    Something I only really just found out—you want your 'table absolutely level, no matter what. I just moved my STD 305-M/SME III onto a perfectly level [and physically rigid] countertop. Now that the turntable is on a level surface, IGD is lower, tracking overall is improved. Previously, the table was only slightly off, with a forward tilt of less than a degree.
     
  12. motorcitydave

    motorcitydave Enlightened Rogue In Memoriam

    Location:
    Las Vegas, NV, USA
    You're welcome, and I agree. That's a great tool for Technics and A-T 'tables.
     
  13. Emperor5353

    Emperor5353 Forum Resident

    I have this tt and I am immediately going to change from that felt mat....I will be terrified to pull out that pre-amp though :(
     
  14. Mark Downing

    Mark Downing New Member

    Location:
    Huntertown, IN
    Thanks to everybody for your information on how to "upgrade" my AT-LP120-USB turntable; based on my past experience with AT cartridges I know I can get better sound out of my Audio Technica AT95E and my AT440MLa cartridges by removing the built-in phono stage. I will add that I bought a Turntable Toys Cork Audiophile Mat and it did tighten up the bass and pretty much silenced the platter/flywheel noise.
     
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  15. FrankieP

    FrankieP Forum Resident

    You guys weren't kidding about this modification and how it significantly changes the sound of this turntable. The difference is indeed night and day especially in the high frequencies. I did a needledrop before and after the modification for comparison and you can download the files in the "Post Your Needledrops (Part 5) thread (post #417). I also did a video and will be uploading it to YouTube as soon as I finish rendering it out.
     
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  16. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    The pre-amp in this 'table is like a speed limiter in a truck. Pull it out and see how the performance increases dramatically. . . . :D

    Got a change since that original post, though. I strongly recommend Stevenson alignment for this deck.
     
  17. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    I live in an old house that shifts. I have to re-level all the time. Just a little off and the whole thing falls apart.
     
  18. Beattles

    Beattles Senior Member

    Location:
    Florence, SC
    Try putting 2 floor jacks and a doubled 2X10 under the floor 4 - 5 ft in front of the TT. Not to hard to do if you don't mind crawling under the house.
     
  19. Mojito Bonanza

    Mojito Bonanza New Member

    I have one question: Is it possible to use Ortofon Concorde Arkiv or Ortofon Concorde Pro with this turntable? Will it be good?

    Thanks for any answer.
     
  20. Joshua T. Anderson

    Joshua T. Anderson Well-Known Member

    Location:
    Ohio
    Thanks for posting this. Quick question for you, after removing the pre-amp, is there ANY way to still record your records using the USB connection, or does bypassing the pre-amp eliminate that capability completely?

    Thanks!
     
  21. The USB connection is on that circuit board. You'll need another way, such as an external preamp with USB.
     
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  22. Joshua T. Anderson

    Joshua T. Anderson Well-Known Member

    Location:
    Ohio

    Ahh, thanks for the heads-up! Do you know of any good/affordable external pre-amp's with USB? I want to remove my pre-amp from the TT, but I also want to retain the ability to record my LPs (and turn some of them into hi-res audio DVDs).

    Thanks!
     
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  23. Ben Adams

    Ben Adams Forum Resident Thread Starter

    Location:
    Phoenix, AZ, USA
    Here you go. http://www.amazon.com/ART-USB-Phono-Plus/dp/B000BBGCCI
     
    vertical likes this.
  24. Anderlfs

    Anderlfs Well-Known Member

    Location:
    Amazon
    You told to don't use BAERWALD GEOMETRY OR A MOFI GEODISC. But when downloaded the "Technics Arc Protractor" (available here), the pdf file shows "The Technics Baerwald Arc Protractor". I'm a bit confused because I searched everywhere and just finded this one. Help!

    About an external pre-amp with USB I recommend this one: http://turntablelab.com/products/pro-ject-phono-box-dc-usb-phono-pre-amp
     
  25. After fiddling around and around with that alignment on my SL-D2, I gave up and went back to the standard Technics method: Align front to back with the overhang gauge (per manual), and centered in the headshell. That's how the AT95E came setup. Audio-Technica doesn't supply the overhang gauge, but KAB sells one for ~$6.

    (It wasn't until later that I came to the conclusion that I wasn't having cart issues with the M97xE, but turntable issues with the SL-D2. I need the tonearm either serviced or replaced. I think that's where my channel problem is.)
     
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