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

I just took mine out. Using a Project phono box mm. Sounds awesome, I feel dumb for waiting a year to do it.

 

I've got a question on this:

Before the removal of the preamp, the turntable grounds to the RCA on the shielding of the two channels, correct? Wouldn't this be possible post-removal? Thus why is an extra ground cable necessary? I don't think my receiver (which I'm currently using for a preamp until I can afford a Pro-Ject Tube Box DS) even has a "ground" input for the phono.

Thanks.

 

All I can tell you is that I followed a YouTube video when I removed the preamp, and they attached a ground wire in the video. And mine hums if I don't hook up the ground.

I believe it was grounded internally to the built-in preamp, which means if you remove the preamp, you have to add a ground.

 

I'm having some bother doing this as the video misses bits (or at least doesn't provide a visual reference). The right RCA cable has a red wire and another wire, the left RCA cable has a white wire and another wire. I assume the other wires are both grounds.

Then the grey wire coming out of the circuit board 9tone arm) has a Red (R) wire, a White (L) wire and a ground wire. So I connect red to red; white to white and ground to ground. So do I connect the ground wire coming out of the circuit board to both of the ground wires in the RCA cables or one of them? If one, which one?

Please help.

 

I completed this a few days ago and WOW what a substantial difference. Sounds like a different TT, fantastic! It has opened up the highs & mids, resulting in better bass as well. The difference is truly stunning. Special thanks to Ben Adams as I would not have attempted it without his confident recommendations. I say to all AT-LP120 owners DO IT. If you don't feel confident doing it yourself, take it to a technician (certainly no more than 1 hours labor). If you want a really good TT for about $300, buy an AT LP120, get a rubber mat and perform the surgery without hesitation.

 

Nice going! Happy to hear you opted to make this tremendous modification. It really does make it a totally different turntable. I got mine when they were still going for about $200 even. I am so happy with how this turntable performs at such a budget price.

 

I wish I could answer this, but it's been years since I missed mine.

Can anyone else who did this recently answer this question?

 

I finally worked it out, hence my success. You attach the 2 ground wires to the one ground wire. Thanks.

 

That was you! Oops, sorry.

 

I've got a PL120 (pre-op) and after reading this thread I'm thinking of taking it to someone...still to nervous to DIY.

In the meantime way way back people were talking about mats.
I have a cork mat that I did make myself and I'm very pleased with it, but I'm worried now about the tone arm height. The mat is 1/4" thick. What should I set my tone arm height to?

 

Anyone have detailed instructions on removing the preamp from an AT-1240?

 

Should be level, I had the same question go here and look at the picture in the thread http://forums.stevehoffman.tv/threads/vta-adjustment-questions-cork-platter-mat.448997/

 

This is perfect - thanks! Now to work up the courage to perform surgery on my TT!!

 

So my girlfriend was out of town for a few days, I got a little board and decided to rip open the lp120 and change the tonearm wires (I already ripped out the preamp a few months ago).

I set out thinking I would take a bunch of photos. But honestly I just forgot and took a few when I remembered.

The idea was to bypass the circuit board completely and solder the tonearm directly to rca jacks that I mounted. I used this wire. 1877 5-Litz-7 Tonearm Wire. Why my friend works at a store and I got some cheap. Normally costs 35 euros a meter



First I unsoldered the five cable that go to the tonearm (that pass throught the sheath) I used these wires to pull the new wires through the sheath and tonearm. I made the mistake of removing the black cable (ground). It was soldered to a screw hidden in the tonearm. I just yanked it out. It was a total PITA to put my own ground cable back in. I had to fully dissassemble the tonearm. I recommend leaving it.




There are two screws that need to be taken out of the tonearm to access the soldering posts. I didnt have a tiny screwdriver so I took out a screw in the tonearm pivot thingy just to the left of the raise lower pulley. Then I wiggle the tonearm out of that little contraption and took the screws out.



Then I desoldered the old wires and soldered the new ones in. Not the hardest solder job but requires a little bit of experience (I am no expert). The posts are really small and the wires are rediculously thin. I drank a bit too much last night and my hands were a little shaky today. Sorry, no photos, I was in the zone and forgot.



After I reassembled the tonearm. Next thing I did was unsolder the sheath and the ground wire that were attached to the board. I soldered those two together with the ground wire I ran to the tonearm.



Next I drilled the holes for the rca's and added a ground lug.



Assembled everything back together. Finished product. The ground cable looks weird (just some scrap multiconductor cable I had)

I've only listened for a few hours but I think that sound has definately improved. I'm not good with technical descriptions. The noise level is lower, the soundstage is larger. Bass is better also. More detail.
When my girlfriend got home, she said it sounded amazing before I even told her I did anything and she normally tunes out my music.

Why do this? I figured why not. There's only so much you can do with a tt made of a bunch of plastic parts. I moved to Europe for my girlfriend and she bought me this turntable (I had a nice vintage Thorens in the US which I sold). Since it was a gift I'm sorta stuck with this for a little bit (been almost 2 years now). And I figured if I messed it up in the process (not saying I ripped it open) and I would just use it as an excuse to buy a new one.

I'm very happy with the results. Overall I payed 15 euros for the cable and 5 euros for the rca jacks and 50 cents for the ground lug. Seems like money well spent to me. It took me about 2.5 hours and I lost about an hour dissassembling the tonearm for the ground wire. There was a piece I had to screw back in inside the tonearm that was very hard to do.

So if you have a little bit of time, a few extra bucks and a little soldering experience go for it.

Also I am no expert. I am an electrician by trade but electronics are not my specialty. My first time rewiring a tonearm

Any criticism (constructive), advice or questions are appreciated. I would be open to ripping it back open to improve on the cabling or something else.

Next task, I'm gonna make my own rca cables.

 

I would love to see the pictures of your work, but they aren't showing up for me. It sounds like you did a very nice job. I've also wondered about re-wiring the tone arm with better wires.

 

ah. sorry. give me a few and i'll repost them. I guess linking to google drive doesn't work

 

I'll just repost the whole thing. Let me know if it works. If so can a gort delete my first post where the pics don't work

So my girlfriend was out of town for a few days, I got a little board and decided to rip open the lp120 and change the tonearm wires (I already ripped out the preamp a few months ago).

I set out thinking I would take a bunch of photos. But honestly I just forgot and took a few when I remembered.

The idea was to bypass the circuit board completely and solder the tonearm directly to rca jacks that I mounted. I used this wire. 1877 5-Litz-7 Tonearm Wire. Why my friend works at a store and I got some cheap. Normally costs 35 euros a meter



First I unsoldered the five cable that go to the tonearm (that pass throught the sheath) I used these wires to pull the new wires through the sheath and tonearm. I made the mistake of removing the black cable (ground). It was soldered to a screw hidden in the tonearm. I just yanked it out. It was a total PITA to put my own ground cable back in. I had to fully dissassemble the tonearm. I recommend leaving it.




There are two screws that need to be taken out of the tonearm to access the soldering posts. I didnt have a tiny screwdriver so I took out a screw in the tonearm pivot thingy just to the left of the raise lower pulley. Then I wiggle the tonearm out of that little contraption and took the screws out.



Then I desoldered the old wires and soldered the new ones in. Not the hardest solder job but requires a little bit of experience (I am no expert). The posts are really small and the wires are rediculously thin. I drank a bit too much last night and my hands were a little shaky today. Sorry, no photos, I was in the zone and forgot.



After I reassembled the tonearm. Next thing I did was unsolder the sheath and the ground wire that were attached to the board. I soldered those two together with the ground wire I ran to the tonearm.



Next I drilled the holes for the rca's and added a ground lug.



Assembled everything back together. Finished product. The ground cable looks weird (just some scrap multiconductor cable I had)

I've only listened for a few hours but I think that sound has definately improved. I'm not good with technical descriptions. The noise level is lower, the soundstage is larger. Bass is better also. More detail.
When my girlfriend got home, she said it sounded amazing before I even told her I did anything and she normally tunes out my music.

Why do this? I figured why not. There's only so much you can do with a tt made of a bunch of plastic parts. I moved to Europe for my girlfriend and she bought me this turntable (I had a nice vintage Thorens in the US which I sold). Since it was a gift I'm sorta stuck with this for a little bit (been almost 2 years now). And I figured if I messed it up in the process (not saying I ripped it open) and I would just use it as an excuse to buy a new one.

I'm very happy with the results. Overall I payed 15 euros for the cable and 5 euros for the rca jacks and 50 cents for the ground lug. Seems like money well spent to me. It took me about 2.5 hours and I lost about an hour dissassembling the tonearm for the ground wire. There was a piece I had to screw back in inside the tonearm that was very hard to do.

So if you have a little bit of time, a few extra bucks and a little soldering experience go for it.

Also I am no expert. I am an electrician by trade but electronics are not my specialty. My first time rewiring a tonearm

Any criticism (constructive), advice or questions are appreciated. I would be open to ripping it back open to improve on the cabling or something else.

Next task, I'm gonna make my own rca cables.

 

WOW! Very nice work. I'm impressed.

 

Close up of the wiring

 

I'm just not brave enough to attempt anything like this. I have a hard enough time just getting electronics to work properly outta the box. I'm very interested in this kind of stuff but its nothing I would ever do even if I has the time.

 

Hey, so I'm having the same issue you mentioned earlier, where the Red wire has an extra cable, and so does the White one. (so there's four wires on the RCA vs just the three, red, white, and ground, off the tonearm board). Then there's the little ground wire that was connected to the spring mounting. Can you clarify which one goes to which? Obviously, red to red, white to white, but what about the three grounds left, and the little spring mount wire? Do I need to add another extra wire like some people have mentioned here?

Please help.

 

The two other wires are the common or negative wires for the rca cables. Put the two commons together (along with the common/negative wire that is attached to the circuit board/in the gray cable). Then a seperate ground wire to your amp (connected to the spring)

 

Well done, enjoy.

 

You connect the two grounds wires (from the RCAs) to the single ground wire (off the tone arm board). You then connect the little spring mount wire to a length of wire (which you'll need to supply), this wire will be the ground which you connect (earth) to your preamp or receiver.

 

Ok awesome, thanks! So I've got it wired properly now I'm hoping. The ground wire (the one I added) is hooked up to the preamp. a Denon "Multi Zone Home Entertainment Component." Do I need to run a separate ground from this machine to the electric box in the wall? My father insists that I do, but I dunno, I didn't have to do that before? He says I should plug a second ground wire into the ground slot on the Denon, and have that run into the wall—so essentially there'd be two cables plugged into the Denon's ground screw: one coming from the LP120 and one going to the wall. Is this necessary do you think?

Cheers, and thanks for the help! I don't know much about electronics.