Audio Solutions Question of the Week: Why Am I Hearing Audio in Only One Channel from my A-T Turntable?

This is the first post in our new “Question of the Week” series. Each Wednesday our Audio Solutions team will address a question they frequently receive and provide detailed steps to help you get the most out of your Audio-Technica gear. This week they discuss a problem that can result from improper turntable setup.

Audio Solutions Team

Question: The audio from my AT-LP120-USB turntable only plays on one channel. How do I fix this?

Answer: The most common cause of either no, intermittent, or distorted audio on one side of the AT-LP120-USB, AT-LP240-USB or AT-LP1240-USB turntables is improper calibration of the tonearm assembly prior to setting the vertical tracking force for the stylus (needle). This improper calibration causes the actual tracking force to be much heavier than what the stylus force gauge ring suggests and, thus, heavier than what the stylus assembly can handle. This excess tracking force typically causes the left channel to have no, intermittent or distorted audio. It is possible, however, for the right channel to be affected instead. Excessive downforce causes excessive deflection of the stylus cantilever. This excessive deflection causes the tiny magnets attached to the cantilever (there is one magnet for each stereo channel) to become misaligned with the corresponding pole pieces, which extend from corresponding coils inside the cartridge. The misalignment of the magnets results in no, intermittent or distorted audio on one side of the stereo signal.

Below we describe how to isolate the problem to the turntable or the stereo device it is connected to, how to properly calibrate the tonearm, and how to set the required tracking force. We’ve also provided a link to our YouTube video that walks you through the setup of the AT-LP120-USB turntable (with the currently supplied AT95E Cartridge). The video may also be used as a general guide for setting up the AT-LP240-USB and AT-LP1240-USB turntables as well.

AT-LP120-USB Turntable Setup Video

To isolate the problem to the turntable or the stereo, the first thing you need to do is swap the RCA plugs at the stereo amplifier or receiver to see if the problem moves with the swap or stays on the same channel. If the problem moves with the swap, the turntable is at fault. If it stays on the same channel, the problem is with the stereo. If it is, indeed, a problem with the turntable, check for proper operation of the cartridge/stylus assembly by lightly brushing the tip of the stylus assembly with a soft brush or the tip of your finger when the tonearm is sitting idle and clamped in the tonearm rest. If you hear the brushing noise on both the left and right channels, the turntable itself is operating properly. But there is, more than likely, an issue with the operation of the stylus assembly when the tonearm is down on the record.

Turn the power dial on the turntable to the off position. Next, confirm that the counterweight assembly is installed on the tonearm correctly. Stand in front of the turntable like you would to operate it and look at the counterweight assembly on the rear of the tonearm. The black stylus force gauge ring on the counterweight should be facing you. It is possible to install the counterweight assembly backwards, with the ring on the back side of the weight, facing the rear of the turntable. This makes it impossible to calibrate the arm and set the tracking force correctly, and can result in an excessive amount of downforce at the stylus/cantilever assembly.

After verifying that the counterweight assembly is installed correctly, rotate the entire counterweight assembly (NOT just the black stylus force gauge ring, which can turn independently of the weight) in a clockwise direction (to the right) until the zero on the ring lines up with the black centerline marked along the top of the tonearm. Confirm the position of the tonearm when the counterweight is set at zero. Is the arm floating perfectly level in the horizontal plane, parallel to the record surface and about 1/8 of an inch above the tonearm rest? Or is the cartridge end of the arm angled downward toward the record (or still sitting in the tonearm rest)? Or is the cartridge end angled upward toward the dustcover?

If the cartridge end of the tonearm is angled upward or downward, the arm has not been properly balanced and zeroed and will need to be rebalanced to float perfectly level. Begin by rotating the counterweight assembly in the appropriate direction: clockwise (to the right) to raise the cartridge end of the arm or counterclockwise (to the left) to lower it.

After balancing the arm, use the clamp on the rest to lock the arm in place. Rotate the black stylus force gauge ring (the ring ONLY, not the weight itselfthe ring will turn independently of the weight) until the zero lines up with the black centerline marked along the top of the tonearm. Finally, to set the actual tracking force, rotate the entire counterweight assembly counterclockwise (to the left) until the desired tracking force (as indicted by the ring) aligns with the centerline on the arm. For the provided AT95E cartridge (green colored stylus assembly) the recommended tracking force is 2.0 grams.

If proper balancing of the tonearm and proper setting of the tracking force does not correct the audio problem, inspect the four pins in the tonearm socket that receives the headshell/cartridge assembly. All four pins should protrude roughly the same distance. If a pin does not appear to be protruding as far as the others, that pin may be hung up and not making adequate – or any – contact with the corresponding pin on the headshell. The pins are spring-loaded in the socket. Typically, depressing the pin with a small non-conductive tool such as a chopstick, toothpick or cotton swab will cause it to pop back out to the correct distance. You may need to depress the pin a few times to make this happen. Reinstall the headshell/cartridge assembly and hand-tighten the locking collar on the end of the tonearm till snug.

If neither the tonearm balance nor the socket pins is the problem, the stylus tip may be damaged or the cantilever may be askew or rotated. It is important that the turntable NOT be running (the platter should not be turning) while you are attempting to balance the tonearm. If you should inadvertently drop the arm onto the edge of the rotating platter, the stylus or cantilever could easily be damaged by the platter’s raised aluminum strobe dots.

We hope you found this advice helpful. Be sure to check back each Wednesday for a new “Question of Week.” And, remember, if you need assistance with your Audio-Technica gear, please contact our Audio Solutions Department. We are always happy to help!

Audio-Technica

52 Comments

  1. I just went through your blog and i really appreciate for the advice given. i guess i am gonna check the site every week.

  2. loss of sound on 1 channel try moving pre-amp selector swictch backwards forwards i’ve had to do this three times with my month old deck (at-lp120usb) so far it’s worked but it is concerning

  3. Hi,
    My player powers on but does not turn over…any ideas ?
    Only have a few times use.
    Model AT-LP120-USB

  4. Hi, I’m having problems with my at-lp60 skipping at the beginning of albums, and also off an on distortion which seem to come out if my right speaker more so than the left speaker.. I have had this player for about 2days and am quite new to the hole seen, any help would be much appreciated!! Also have tried dif record, and tried cleaning them..

  5. Hi! First thing,thanks for this blog. I’m having problems with my AT-LP120-USB. After a little more that 2 years of use, I am encountering either no, or intermittent sound on left channel. The problem moves when swapping the cables. I had followed the indications in this blog with no success. What’s next?

  6. I have experienced nonstop issues with the setup of the AT-LP120bk, tonearm drift, inaccurate lowering of the arm, VERY distorted audio (if I actually can hear audio), and +8 hours of frustration trying to troubleshoot the problems, finding solutions and implementing various protocols. I contacted my point of purchase for exchange/refund, and they would not accept a return due to the equipment having something in it that is considered HAZMAT. I’m not a seasoned pro, but I’m also not a beginner either, at this point I’m ready to throw the unit in the garbage. I expected a much higher quality product, and I’m extremely disappointed with the “Christmas present” that I have received this year.

  7. This is exactly the fix I needed, which is to say, I was just wasn’t following the calibration instructions correctly. The video instruction set me straight. Both channels clear as a bell now. Thanks!

  8. I have this very same issue. No sound on left channel. I tried brushing the tip gently and I hear sound only on the right channel. What would be my next step here?

  9. Hello, I would like to know why when I replace the needle with ATN95E the left channel sounds less mor than the right channel?
    And when I reconnect the original needle provided by the turntable AT-LP120-USB sounds great.
    Could be the new needle is damaged?

    In advance thanks al lot for you help.

    Regards

    Mario

  10. What can I do if I tried the brushing the stylus technique you described and I still only got sound out of the left channel when I did that?

  11. Balancing the tone arm worked!! Thank you so much for this information.

  12. Thank you so much for the clear instructions – I purchased this as a gift for my daughter and when I heard it several months later noticed the distortion. Now it sounds fantastic.

  13. I have a different problem. I love the turntable and what it can do, but connected to my olde carver amp and preamp with ESS Heil amt1b it sounds dull. I’ve swapped cartridges from my other unit with no change. Any thoughts ?

  14. I have contacted them and got an email ask No questions. I replied and it’s now been 3 weeks since my return email with no response.

    • Hi Bill, we can have our Audio Solutions department email you directly to help resolve your issue if that’s okay with you. Is the email you’ve listed here the best way to get in touch with you? Thanks! – A-T USA

  15. Thanks much for the insights, was hearing lots of distortion
    through my left speaker.
    Went through the whole gamit of diagnostics, and was ready to return the turntable until I found this site. Went though the entire arm setup again and it sounds great now. Something to be said about reading the set up instructions the first time.

  16. Thanks so much for this post. I’ve got this exact problem and went through all the troubleshooting steps as directed. The problem is definitely with my turntable. Interesting I had sent it in to AT for service and the report was that “it passed all tests as expected”. It’s a problem with the turntable but I’m not sure what to do next. Any advice?

      • Happy to email but I need to share an update here first. Having lost confidence in AT customer service and repair, I found a local guy who would look at it and, sure enough, it was a faulty connection to the pre-amp board. It cost me a couple hundred bucks but I didn’t have to send in the turntable for service and wait for a few weeks with the risk of getting the same “passed all tests” result. The gentleman who worked on my turntable said it was clear that it had never been opened. It unfortunately leads me to believe that they didn’t even look at it. It also makes me wonder if this is a frequent enough problem that merits its own blog post. So, back to the top line, I’m happy to email but I got my problem resolved elsewhere.

        • Hi Don, we are so sorry to hear about your negative experience with your A-T turntable, and we have forwarded your comments to the appropriate personnel. Thank you for bringing this to our attention and for the blog topic suggestion. We will definitely look into this issue further. Thank you! – A-T USA

  17. I really hope someone can help me with this. I bought my LP-120 a little over a year ago. Set everything up including tone arm balancing and anti skate. All was fine until a couple of months ago when the signal out of my right speaker wasn’t coming through. If I picked up the tone arm and reset it it would work for a bit but no more than a few seconds. So I recalibrated everything again and this time downloaded the stylus protractor to make absolutely sure. Now I’m getting hit and miss signals from both sides but mostly the right. I’d really appreciate any help you guys can give me.

  18. AudioTechnica LP60 turntable sends left and right signal to my home stereo amp and speakers just fine BUT it’s usb output sends left channel only to either of my PC computers. One computer is windows 7, the other is windows 10. I am recording using Audacity, set for stereo but i only get the left channel signal on both tracks no matter how i set up the audacity tracks.

  19. I have meticulously calibrated the tone arm of my AT-LP 120 USB using related protractor and pressure gauge.Besides, the TT is rested upon a perfectly levelled plinth. And yet, it is detected that the ANTI SKATING KNOB of the turntable is not at all functioning. It remains dumb all through its dialing from minimum (0) to maximum (7) position. As a consequence, instead of remain static, the tone arm is invariably sliding from the edge towards the center when placed on any blank DVD for testing. Please, suggest how to rectify it.

  20. Followed all steps. Brushed the stylus only got sound from right speaker

  21. REpost to my comment from March. I have calibrated, re-calibrated and re-re-calibrated this thing more than I can remember and checked all contacts and pins. I even bought a scale specifically to measure the counter weight. EVERYTHING is perfect and the problem still persists. Oh, I even bought a new Ortofon cartridge. I’m convinced there is an issue with the internal wiring of the turntable. At this point I’m ready to just toss it and buy a RELIABLE turntable. Oh, the “assistance” I got from AT customer service was nothing more than an email describing everything in this article.

  22. Hi, I’m looking for feedback on how to dampen the rumble from either the turntable platter or the motor. Not sure. The noise is more distinct when the volume is turned up and when it’s either a quiet song or in between songs. It’s bringing me to the point of selling it for a better turntable or doing mods which will mean spending more money and affecting the value, but wanted to get your thoughts on it.

    PS the platter itself is slightly warped and the rumble is more pronounce when it hits the dip of the warp. If I was to getting a better engineered platter, where would I go to replace it? I can also take video with sound and send a link to illustrate the problem.

    Please, any help would greatly appreciated.

    Thank you

  23. The right channel on my Audio-Technica AT-LP-120-USB serial number C16230022378 either doesn’t work or stops working after 1-2 records? I have recalibrated it per the instruction on this blog but it does not help. I have replaced it with my son’s LP-120 and the system works great. I have calibrated my son’s LP-120 and it works fine? Can I get this repaired?

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