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

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

  1. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    I feel dumb for waiting three years to do it. My second new one was three days old when it got modded. :thumbsup:
     
  2. Martindfletcher

    Martindfletcher New Member

    Location:
    San Diego

    In all honesty the difference after the would require a hearing issue not to notice. Bigger difference than a cartridge update.

    I prefer this method though

    AT-LP120-USB Preamp removal - Vinyl Engine ยป
     
  3. djiceberg729

    djiceberg729 New Member

    Location:
    Miami, FL
    I am about to do this to my LP120, what do you guys use to cover the hole left by the USB plug? I'm concerned with dust etc getting into the internals
     
    Last edited by a moderator: Jan 27, 2017
  4. raq0915

    raq0915 Forum Resident

    Location:
    \New Jersey
    Im still extremely nervous to do this. To be entirely truthful, Im thinking about just saving up and buying a new TT all together for fear of ruining my 120 by removing the preamp
     
  5. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    I didn't remove the USB plug from the case. I just don't use it, since it doesn't connect to anything. :D
     
  6. djiceberg729

    djiceberg729 New Member

    Location:
    Miami, FL
    Oh ok, for some reason I thought it was built onto the preamp and would leave a hole in the case. Thanks!
     
  7. Ben Adams

    Ben Adams Forum Resident

    Location:
    Phoenix, AZ, USA
    Huh. I could be remembering incorrectly. I'm at work or I'd look.
     
  8. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    Or you could pay around $75 and have a professional do it. I called a stereo shop asked specifically about the procedure and they said they were familiar with it. They quoted me the price of one hour labor to do each TT. I brought in the two and they were ready for pick up three days later. Now it was a bit of a hassle to pack them up and drive to some unknown neighborhood in North Seattle twice but overall well worth it. I guess it depends on where you live and available options though. Super highly recommended if you are able to find someone to help ya out!
     
  9. Joey Pactwa

    Joey Pactwa New Member

    Location:
    Orange County
    Hi there,

    After scouring the forums and realizing that after years everyone is still active on the forum (thank the vinyl gods), I've decided to sign up and ask you guys something that has been bothering me ever since I took out the preamp out of my LP-120.

    After following numerous guides on YouTube and taking the courage to do it myself, I successfully removed the preamp (via heating the solder method and not the cutting method) out my TT but with one small problem: there seems to be a slight buzz on my right channel coming from the speaker. This isn't the usual ground hum you get when you don't have the ground to an external preamp (btw I'm using the USB phono plus), but very similar and only in the right channel. I can still use the record player for casual listen, as it only is truly noticable when nothing is playing, but if I were to start recording music to my computer, I know it would be extremely noticable. Not to mention that it also indicates I did something wrong and that irks me more then anything.

    Anyways, any help needed. I'm sure someone out there will be able to help me out with this one.
     
  10. AppleCorp3

    AppleCorp3 Forum Resident

    I've decided to go for it this coming weekend.

    I'm a bit apprehensive considering that my model is a PL-120 which folks have said is different on the inside, but based on the videos I think I've got the gist of it.
     
  11. The Slipperman

    The Slipperman Well-Known Member

    Location:
    Boise, Idaho, USA
    I did this procedure but tied the wires together, no solder. It worked great, unfortunately I can't really suggest anything to fix your problem that you probably already haven't thought of (maybe cut the soldered parts off of your right wire and try tying the two ends together).
     
  12. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Starting to finally consider doing this to mine. No soldering experience very little mechanical experience. Is this something that could be done in a few hours? Or is it longer?
     
  13. djiceberg729

    djiceberg729 New Member

    Location:
    Miami, FL
    I'm a technical invalid and just did this in about 3 hours. Sounds so good
     
    guidedbyvoices and Jam757 like this.
  14. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    It seriously is an eye opener. They should just release a non-usb version to avoid this hassle. Congrats on your successful surgery! You'll now want to play every record you own.
     
  15. AppleCorp3

    AppleCorp3 Forum Resident

    The non- USB version was the PL-120 but still has the built in preamp.

    There are no vids online on how to do that mod, unfortunately.
     
  16. guidedbyvoices

    guidedbyvoices Forum Resident

    Location:
    Alpine, TX
    Awesome. Looking now for a preamp. Did you buy an external preamp and live with it a while before removing? To hear the difference between bypassing the preamp vs removing it?
     
  17. Jam757

    Jam757 Forum Resident

    Location:
    Seattle
    I should have clarified non usb and non preamp.
     
    AppleCorp3 likes this.
  18. djiceberg729

    djiceberg729 New Member

    Location:
    Miami, FL
    I got a Hagerman Bugle2. I did try it for like 3 seconds but knew that I was going to end up removing it so didn't really pay that much attention.
     
    guidedbyvoices likes this.
  19. Joey Pactwa

    Joey Pactwa New Member

    Location:
    Orange County
    So to comment back and give an update, it appears that it could have been a number of things: 1) Cheap wires 2)Dirty Grounding in my house. My dad had me remove the wires and put in wires that are shielded, those real expensive ones. The sound is now 99% gone, with the 1% happening when I put the gain and my speaker volume all the way up. It seems that the cheap cables were, well cheap and pickup interference from other cables around the area. Glad that this problem is fixed.

    HOWEVER, now I have a new question for the readers of this thread: Motor noise and slight pitch changes when playing back. I've only dealt with belt drives in the past, so I know that some motor noise may be experienced, but how much and how loud? Also, I notice that maybe half way through any given record, when I hear long prolonged notes (i.e. an open guitar note for a few seconds) I can hear the fluctuation of the pitch ever so slightly. It almost creates a cool chorus effect to it, but when you have listen to a certain song for over ten years, it sticks out like a sore thumb. Any help with this, or is this the nature of records? (Also some backstory, I've listened to records for years, but it wasn't until I got this TT that I've begun to really LISTEN)
     
  20. P2CH

    P2CH Well-Known Member

    The main reason I chose to leave the preamp in my LP-120 is because I don't use the deck for critical listening. It was mainly purchased because it can spin 78 rpm. But too, I want the ability to have a TT I can plug and play into audio systems that don't contain a phono preamp.

    I currently have it plugged into my 1946 Sparton radio console for playing LP's while I attempt to get a little exercise while using a glider. It's surprising that such an old system can sound pretty good with just a 10" electromagnet single cone speaker. I hear things in recordings I don't normally hear, maybe because all of the other things normally heard from the other drivers takes away from it?

    It's also sort of nostalgic too.
     
  21. crdemers72

    crdemers72 New Member

    Location:
    Madison, WI
    I got the LP120-USB this Christmas and ALMOST returned it due to the cheap RCA cables, overall sound, incessant skipping and "skidding" into the first part of an album (grrrr...not cool on my vintage Metallica albums!). However, once I learned about how sensitive this turntable is with settings, I made the following adjustments. These are NOT cheap and require a lot of fiddling around, but are worth it!

    * Balancing with a dead accurate level: $Free
    * Printing off AT's protractor for the AT 120: $Free
    * Using calipers to make sure distance from end
    of arm is exactly 52mm from the needle: $Free (w/ $50 set of calipers)
    * Cheating on the above step with AT's gauge: $15 from Amazon
    * Mirrored protractor (Stevenson A): $15
    * Cork/rubber mat from Amazon: $30
    * LP Gear Shure M97xE setup with headshell: $149
    * Improved heavier counterweight (AT-CW1): $30
    * Center record weight with "balance" bubble: $30
    * Record cleaning brush / system: $30
    * Scale to measure stylus force: $15 (so, so, so worth it)
    * Stylus cleaner: $10
    * Isolation pad since the kids are heathens: $80 (probably should have used a soft spiky sound tile cut to shape)

    So far, we are up to $404, which is a good bit more than my wife paid for the turntable itself. However, I set it up with the above parts, and I went from "I'm returning this s***" to "Wow, this is pretty awesome sounding." The trick with the needle is that on a protractor, to get it right and make the stylus track properly, you need to make a SLIGHT adjustment in the cartridge so the cartridge is not completely straight-looking in the headshell. A mirrored protractor makes this adjustment obvious, even though I did it successfully with the paper cutout to check. Also, the proper initial tracking force (just on the Shure M97xE) is 2g WITH the attached needle brush down, which is how I use it. At 0g, the AS works as advertised in mid-air. At 1g, I needed a little over 1 AS, but at 2g, the AS does not work properly on test records but I found a sweet spot using headphones of just under 3 (around 2.75). The needle on the Shure is a different shape than on the stock cartridge, which could cause a difference. The height adjustment is almost a joke; anything but the lowest setting makes the weighted end of the tonearm too high during playback.

    At this point, the needle tracks fine even on longer LPs, no more skidding into the first song and no more grumble toward the end of longer records (Master of Puppets by Metallica and other longer LPs gave me issues originally). In fact, there was no more skipping, even with me walking near the record player. The turntable now sounded REALLY good and I was impressed. So good that my wife wanted to listen to old metal with me one night. I have some original CDs from the '80s of Metallica, Megadeth and Testament and the LPs ALL sound better, even the picture discs (...gasp!). The CDs are awful next to the LPs (the changer is a nice albeit an old Denon carousel).

    I also did discover later that the original stylus was damaged (the needle was bent to one side). Could've been me; I don't know.

    So, $654 in, what else needs doing? I am going for the pre-amp removal and replacing it with an aftermarket model. I am also going to replace the RCA cables and solder in some shielded Monster cable I have from the 90s. I'm also connecting a ground wire using spade connectors into the spring grounding post to the pre-amp outside.

    * Removal of junky internal pre-amp: $Free (w/ $100 in soldering supplies)
    * ART USB pre-amp: $80
    * Monster cables (recycled from VCR cable): $60 back in the day
    * MIT Terminator cables from pre-amp to amp: $100 back in the day
    * Ground wire: $Free (Using black wire from spare 14g electric cable to spade connectors out)

    So, this brings the total to $894 (but I am recycling cables). $734 if you subtract the cables. Is this turntable worth $750?

    Yes. So much so that I am getting rid of my existing CD changer and getting a single-disc higher-end model since it sounds horrible next to the turntable. I may even switch out to my single-disc Yamaha CD player from 1989 and see if there is an improvement. At the exact same volume levels, the TT sounds better, hands down every time. The only way you can tell it's an LP is if you hear an occasional pop. Overall I am already very happy with the turntable, but think it will be amazing with the pre-amp removal. It's a pricey piece of gear, yes, but in a suitable sound system it's worth every penny. You can get another turntable for $750 but you probably wouldn't take it apart to tinker! I'll post results after I replace the pre-amp this weekend.

    - Colin
     
  22. Rentz

    Rentz Well-Known Member

    Location:
    Texas
    Finally did mine this weekend, took maybe an hour. Would have been less if I had wire strippers that handled smaller gauge wires. Sound improvement is pretty good with a uturn Pluto preamp.

    I did mine with wire twist on caps rather than soldering, in hindsight I could have saved a lot of effort by just soldering new wire straight to the board.

    Some tips for others that might help in the future:
    Make sure if using the twist cap method not to cut the wire too short from the preamp. I cut a little too much off which made it a lot harder to strip enough wire down to twist to the rca.
    If you're eyesight isn't the greatest I'd highly recommend a hands free magnifier with a light, would have been way easier for me with one.
    Make sure your wire strippers can handle the thing gauge wires, will save a lot of effort and wire.

    Taping the spacers on with some masking tape made reassembly super easy

    If you have a soldering iron and are comfortable doing it I'd recommend either soldering the wires together and putting heat shrink over the connection or wiring straight to the board. I thought the twist cap method would be quicker and easier but it really wasn't
     
  23. The Slipperman

    The Slipperman Well-Known Member

    Location:
    Boise, Idaho, USA
    I noticed that about the cartridge, it needs to be a little off center pointed towards the center as I recall. So you liked the Shure M97xE with heavy metal on this turntable? I tried out the Shure with original Iron Maiden LPs and a couple of others and thought it was way too quiet. When I have money to burn, I want to try out AT's 440MLb stylus.
     
  24. adm62

    adm62 Forum Resident

    Location:
    Toronto, Canada
    Plus about $300 to buy the TT so that's about $1200 invested, plus all the work. For me that would be very questionable.
     
  25. crdemers72

    crdemers72 New Member

    Location:
    Madison, WI
    I included the $250 (it was on sale) for the turntable in the final calculation :). Goofed on that one... If you got decent cables nowadays you may spend $60 for both sets to and from the pre-amp. Back in the 90s though people paid $$$ just for cables with buzzwords...I was one of them.
     
    Last edited: Feb 21, 2017

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