Removing The Pre-amp From An At-lp120

Discussion in 'Audio Hardware' started by tylershippit, May 4, 2015.

  1. tylershippit

    tylershippit Well-Known Member

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    I recently bought an at-lp120 and am overall very happy with the turntable. Luckily my receiver is an old technics model from the mid 80's with a phono input so I don't have to use the built in pre-amp and listen to that god awful buzz.

    However, I've read some articles online that suggest removing the built in pre-amp altogether drastically improves the sound produced from the turntable, however I'm hesitant to take apart my table due to the fact I just bought it and I'm relatively inexperienced with modding turntables.

    Has anybody here removed the built in pre-amp from their lp120 and can vouch for the sound improvement?
     
  2. TimmahTao

    TimmahTao Well-Known Member

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    Yeah, it's a flaw that doesn't get talked about very often. Even when you disengage the pre-amp of the LP120, the signal is routed through the board and picks up that buzz or interference. You'll void your warranty and I hope you are handy with a soldering iron, but you'll get sound that is just better, assuming the phono amp in your receiver is actually better. The mid-80s were not the best time for vinyl.

    I think there is misunderstanding about what market the LP120 is targeting. It is not an audiophile product. It is not a prosumer or dj product. It's meant to be the high end option for the casual listener or DJ starting out with vinyl looking for an affordable option. It has a built in pre-amp because the targeted consumer is someone who wants a mechanically robust deck with full adjustments, who might not have a dedicated vinyl set up with a high quality phono stage. Look at any turntable made by a company with an audiophile line and you'll see that they don't have pre-amps. Neither does any turntable made before the recent resurgence.
     
  3. tylershippit

    tylershippit Well-Known Member

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    I was originally eying up a Rega Rp1 but after shipping I was looking at about a 700 dollar table and since a local electronics store carries audio technica products I managed to grab one for about 400 dollars. I think I'm going to try to save for a Rega or a Pro-ject while using the AT for samples and casual listening. but as a whole, you are right. the lp120 definitely markets itself as something it isn't.
     
  4. TimmahTao

    TimmahTao Well-Known Member

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    Yeah, I think that the Debut Carbon DC might have been a better option for you.

    AT doesn't actually market the lp120 as a audiophile turntable, but the consumer market has seen it's similarities in form and build to the Technics 1200, and assumed that it was equal. Because it's such a ubiquitous design and a decent player for what it is (high quality consumer), it gets tossed around as the default suggestion for a lot of people. For a lot of listeners it IS a good fit. It's decent sounding, robust, and relatively inexpensive to integrate into the existing set up of a person trying vinyl seriously for the first time.

    It's not a good fit for an audiophile and never has been. Audiophiles aren't just along for the new vinyl fad; they never stopped listening. That's why companies like Rega, Thorens, and Linn still exist, as well as the more esoteric brands.
     
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  5. Corycm

    Corycm Well-Known Member

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    Dammit. @TimmahTao pretty much beat me to the punch while I was in a meeting. Listen to him.

    It's not a crime to be learning about equipment, so don't feel like you got duped. Certainly nothing wrong with outgrowing equipment (anyone who lives with you and has to deal with your closet full of post-upgrades may disagree).

    That said, I'd love to see some competition in that $250-275 space when people ask me what to buy for their first. I want people in this hobby with me, not kept out. It's an attractive price point for a starter.
     
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  6. TimmahTao

    TimmahTao Well-Known Member

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    BLAMMO!
     
  7. Brando

    Brando Well-Known Member

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    Are there any online tutorials for this?
     
  8. Brando

    Brando Well-Known Member

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    If you bypass the preamp do you also bypass the usb out, because I like having that option?
     
  9. NoCo_Dave

    NoCo_Dave Well-Known Member

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    I don't have this turntable, but did find a video:




    I wouldn't necessarily recommend doing the way this guy did, using wire nuts to reconnect the outputs and I'm not sure what board is left between the cartridge and outputs, that would bug me. But at least it seems to take out the USB and preamp board.

    @Brando, it does look like preamp gone means the USB is also gone.
     
  10. TimmahTao

    TimmahTao Well-Known Member

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  11. Onefoofighter

    Onefoofighter Member

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    I've had my ATLP120 for a year now and have been incrementally upgrading it. I've replaced the felt mat for leather (looking to get a cork one soon maybe), upgraded the cartridge to the AT440mla, and added an external preamp Art DJ Pre II. This seemed to be the last upgrade and also most invasive one.

    I followed that video and easily removed the preamp two days ago. You just need the right tools, like a good wire stripper, small enough wire nuts, and an extra wire for the ground. My wire stripper is really old and wasn't doing a good job on the really thin wires, so I used a scissor carefully. I have some wire nuts around in my house and luckily they were just small enough. If it isn't catching because the nut is too big, try folding the wire in a little loop on the end and it should be wide enough to catch the thread. It took me about an hour to do this. As for the extra ground wire, I used some speaker cable and stripped the ends on both sides and spliced them together into one. Probably not necessary as I could have peeled the cable apart. It's connected to my preamp now.

    I haven't done extensive listening yet but I've noticed right away that the noise floor has dropped away and I don't hear as much low rumbling noises. I don't hear echo I used to hear through the speakers when I would tap on the table my turntable is on. Overall the unwanted noises of spinning seem to have been drastically lessened by this. As for frequency responses and sound, I can't immediately comment. I thought it sounded pretty good before, but with an easy modification I can theoretically get better sound.

    It will knock out it's USB out functionality, but I personally have never used that function before. If you really need that option, then the viable option would to get a preamp which has a USB out like this below.

    http://www.amazon.com/gp/product/B0...rd_t=36701&pf_rd_p=2091268722&pf_rd_i=desktop
     
  12. JoeU

    JoeU New Member

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    I need help with the Amp removal.
    I removed the amp and thought everything was good and when I plugged it in to my new preamp (Pro-Ject Phono Box MM), I was receiving buzz (hum).
    Checked everything and all looked good.

    I removed all the solder points and re-soldered (a lot cleaner) and again... buzz (hum)!

    I have again removed the solder points and need someone to tell me if I have a continuity problem.
    Are all red, white and black on the same plate?
    Red, white and black all have continuity when checked.
    The speakers are working fine, but I can't seem to get rid of the buzz.

    Ideas?
    Do I have a faulty preamp?

    Un-soldered
    IMG_1926.JPG
    Re-soldered
    IMG_1936.JPG
    Extra Ground (to preamp)
    IMG_1937.JPG
    There is continuity between A - B / A - C / B - C (Is that correct?)
    IMG_1926.JPG
     
  13. mcherry

    mcherry Spam Slayer ☠️ & Moderator Extraordinaire

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    I forget, @Ben Adams you know something about this, right?
     
  14. JoeU

    JoeU New Member

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    Any help would be appreciated.
    I have watched videos and done research and everything looks good but I'm dealing with the hum.
    Someone changed the tone arm wiring and I'm not sure if that would help.
     
    Last edited: Sep 3, 2018
  15. Ben Adams

    Ben Adams Well-Known Member

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    mcherry and HiFi Guy like this.

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