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

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

  1. draden1

    draden1 New Member

    Location:
    des moines, ia
    Thanks for the suggestions, I am going to try that protractor linked a couple posts back and see if that makes a difference. I'll report back what I find.
     
  2. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    I would rate the sonic upgrade of the pre-amp removal a 10 out of 10. It was not the least bit subtle and the smartest thing I ever did with my system.
     
  3. picassoson

    picassoson Well-Known Member

    Location:
    New York City
    I'm not good at mechanical stuff, but gave this a try - and ended up ruining my turntable... so I just bit the bullet and bought a refurbished Technics SL-1200MK5.

    One of these days I'll probably try and open up the hood again, and undo the damage. I actually didn't mind the sound of the internal pre-amp... even though I know the EQ rolled off the top-end and probably boosted the mid/low end. I actually personally prefer that kind EQ, but now have the option to control it a little more with my Marantz receiver.
     
  4. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    What did you do wrong that ruined the turntable? Your lesson learned could help someone else thinking of trying it.
     
  5. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Did you try bypassing the internal preamp and using an external preamp first? My experience was bypassing and using a schiit mani was an 8 out of 10 bump, removing the internal a 3 out of 10.
     
  6. picassoson

    picassoson Well-Known Member

    Location:
    New York City
    You can see what I did here:

    At-pl120 Preamp removal

    I think I cut the wrong wires, and then when I tried to re-solder them my solder job may not have been great. In my turntable there was an extra board connected to the pre-amp which I'm still not sure what the hell it did. I can get sound out of the turntable now, but there is terrible distortion and playback is at a really low volume.
     
  7. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Ah man, that sucks. I'm not technical, and definitely confused the hell out of myself, and that was with the same model. I imagine trying it with a slightly different model was even moreso.
     
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  8. draden1

    draden1 New Member

    Location:
    des moines, ia
    I tried the protractor from above and I was virtually there already. I tried one last try with the Technics overhang gauge and found I was a bit too forward so I moved it back in the head shell, then I tweaked it ever so slightly inward per another comment above. Voila, while turning up the volume again to loud levels the forwardness of the "s, sh, c" has been tamed. All is well again, can't wait to go through my records, thanks again everyone that chimed in!
     
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  9. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    It never fails to amaze me how some of the smallest adjustments can make a big difference!
     
  10. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    Glad that old blog is still helping folks!
     
    guidedbyvoices likes this.
  11. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    I took my two AT-120 turntables to a shop and had them remove them for $70 each. When I picked them up the preamp boards were in a little baggy. I did use tutntable preamps before and still do. I think the purpose of the removal is that you cannot truly bypass the on board preamp. I have the AT95e cartridge on one TT that I mostly use with headphones (80% of my listening) and a Shure m97xe, Azur amp, and Kilpsch Heresy's on the other, sounds amazing. I may even lean toward the At95e for a more balanced and warm sound over the m97xe. The preamp removal was a great improvement although maybe I do hear a bit more surface noise, not sure.
     
  12. Channel Z

    Channel Z Forum Resident

    Location:
    Illinois
    I also removed the pre amp in mine to excellent results. Bought the overhang gauge for better alignment (why this very cheap simple tool is not included with the turntable is baffling). The other very cheap upgrade is a cork mat. I purchased a 12 inch mat at Home Depot for less than$5.00 that works great. The bass was flabby sounding with the original felt mat and now is tightened up substantially. 3 upgrades that definitely made a difference that cost me less than $15.00 and some time, this is with the AT95e cartridge I am still using.
     
  13. Disionity

    Disionity Active Member

    Location:
    Missouri, USA
    Could anyone with the upgraded counterweight give me the approximate weight? I'm wanting to see if I can modify the stock one and would like it to weigh roughly the same as the official upgrade. I believe somebody on here achieved this by wrapping solder around the middle section. Will this even work that well or should I just pony up the $30?
     
  14. Clint Anderson

    Clint Anderson New Member

    Location:
    Eau Claire, WI
    just removed my preamp, instantly found the change noticable and amazing
    maybe if the turntable had sounded like this when i got it i wouldnt have gotten the technics sl-qd22 sitting next to it
    i just twisted up the wires and put some shrink tubing and electrical tape on them to hold them all in place and keep them from bumping around
    maybe if i feel really motivated someday i will take it apart and solder it but for now its great

    also regarding the counterweight, i bought the counterweight for a ortofon cart i had that was way light, in retrospect, i wish i had tried using something like a magnet, etc to weight the tonearm more, i feel kinda like the counterweight, which i think is just a few oz more, 7oz? is kind of a rip off at $35 or whatever
     
    Jam757 likes this.
  15. brimuchmuze

    brimuchmuze Forum Resident

    I'd be curious to hear a before and after needledrop.
     
  16. Clint Anderson

    Clint Anderson New Member

    Location:
    Eau Claire, WI
    so did anyone ever determine what the board is that is between the tonearm and the preamp?
    what is its function and can/should it removed or bypassed as well?
     
  17. thesituationist

    thesituationist New Member

    Location:
    USA
    Total vinyl noob here - nabbed an LP120 on Black Friday. Out of the box with the internal preamp, I found the sound quite dark and rolled off in the treble. I'm a big fan of bright audio - Klipsch speakers are my go-tos, for example. Needless to say, this doesn't seem like a great match, thus far. I have a setup where it's easy to do quick A/B testing against the same song coming out of my PC->DAC, and I vastly prefer the clearer treble of the latter.

    I almost immediately ordered a DJ Pre II preamp in the hopes it would make a big difference, but in terms of the darkness and overall sound character, I was underwhelmed with the magnitude of any changes vs. the internal amp.

    So now my predicament - if my main goal is to get (significantly) brighter sound, which of these is going to get me the most mileage?

    1. Removing the internal pre-amp, but keeping the setup identical

    2. Replacing the stock cart with a fairly cheap one (<$100) that's more known for bright characteristics

    I would assume (2) will yield the more pronounced change, and I'd almost prefer that to voiding the warranty and risking turntable death so soon. If that's correct, does anyone have any recommendations?
     
  18. Stefan

    Stefan Forum Resident

    Location:
    Montreal, Canada
    I'd put an At120eb cartridge on it. You should be able to find one for about $100 and then later on if you want even better tracking (the 120 tracks just lps just fine) add either an ATN44MLb or the newer VTN40ML stylus. All of these will be be much brighter and great trackers
     
  19. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    I found removing the internal preamp improved clarity but didn’t affect eq type stuff, not like a cart or preamp affects the sound.
     
  20. marcob1963

    marcob1963 Forum Resident

    Removing the pre amp is a must, the improvement will surprise you, it is quite significant. I think you'll find that the "darkness" will lift and the treble roll off will go.

    I'm running an AT440mla cart on mine and its a great synergy, particularly if you like bright (I would describe it as detailed).
     
  21. thesituationist

    thesituationist New Member

    Location:
    USA
    Thanks for the replies. Sounds like the cart replacement is the way to go.

    I see the AT100e is available for a bit under $100, and it looks like it's the predecessor to the 120e mentioned above. This comparison against the 95e (which, frankly, sounds embarrassing there) sure has me thinking it will be just what the doctor ordered. Any last minute cautions against this option?

    Also, is there any reason to get anything other than another AT-HS1 ($20) in the same price range for the headshell to pair with it?
     
  22. thesituationist

    thesituationist New Member

    Location:
    USA
    The saga continues...

    AT100e came in today and I promptly installed, expecting an epiphany-type change. Instead, I found the sound still considerably darker and more rolled off than my DAC when routed through the ART DJ Pre II.

    What's intriguing and could possibly be useful for others in this thread: I found a few mentions here, and on the YouTube instructions, claiming that it's the bypass circuitry that's severely rolled off, whereas using the internal pre-amp is less so. Switching back to the internal and now using the AT100e, it does almost seem as if the AT100e->internal amp is noticeably brighter than AT100e->bypass->ART. I have no means of recording to do a definitive test, though.

    I will likely to performing the internal preamp removal soon and update further. If I had it all to do over again, I wouldn't have bought the LP120 in the first place. Between the TT, amp and cart/tonearm, I'm pushing $400 and still don't have the sound I was looking for unless I void my warranty. On the plus side, I've learned a hell of a lot the past couple weeks, having never owned a TT.
     
  23. marcob1963

    marcob1963 Forum Resident

    The preamp removal is the key, that's where a substantial sonic improvement will come from. It will make a far greater difference then swapping the AT95e with the AT100e.

    Also, you want to get rid of the felt mat and replace with rubber (or something else), that will result in the tightening of bottom end.
     
  24. nosliw

    nosliw Well-Known Member

    Location:
    Ottawa, ON, Canada


    Scroll to 20:09 for the sound comparisons of the built-in on the LP120 versus his Nikko Pre-Amplifier Beta 20. Also, the video I embedded is by far the most in-depth and most graceful way of removing the built-in phono preamp, which the others simply ripped it out completely.
     
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  25. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    The preamp and a cart upgrade you likely would’ve had to buy to jump into the vinyl hobby anyway, and can be taken with you most likely to the next turntable. For someone with a very precise understanding of the sound they want from vinyl, you may need to go bigger than a $400 investment.
     
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