Top audio wave is flat, bottom is ok

I am transferring music from vinyl to my computer. My first attempt was successful. When I tried a second record, the top audio wave was flat and the bottom one was ok. I closed and reopened Audacity, and this time both audio waves were working as before. That was the last one. Since then, for every record, the top audio wave is flat while the bottom one is ok. This happens with records that I had transferred before which did not have a problem. Can you help?

Shift+Command+4 and draw a box around some of the damage.

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That should put a picture file in your desktop. Post it here on the forum.

Scroll down from a forum text screen > Attachments > Add Files.

The odd part of the problem is not that it’s happening, it’s that it changes. That’s most unusual.

vinyl to my computer

How? Conditions, connections, and model numbers.


I just added the screenshot, hope you can see what. The crazy thing is that I had just recorded this album and everything was fine! I tried again just to get the screenshot and this started happening. This is also the first time that the bottom line is flat. Usually it is the top. A couple of times the problem got fixed when I rebooted my computer. But other times the reboot didn’t work. Hoping there is a simple fix to this!! That’s for responding!
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I just saw your How? question at the bottom. It is random, sometimes it works, most times it doesn’t. I am transferring from an Audio Technica 120 USB using a USB cable to my MAC Airbook using Mojave - and I have checked yes in System Preferences/Microphone/Audacity (latest download).

Since that “flat line” doesn’t appear to be “dead flat”, it’s looking like an analog problem (something in the turntable). Can you hear what the “quiet channel” sounds like? Pure noise and/or a reduced signal? You can run the Normalize effect and “Normalize channels independently” to bring-up the weak channel (hopefully) to the point you can hear it. That’s not a fix, it’s just to get an idea of what the problem is.

Do you have something to plug the analog connections into? (Your stereo or TV?) Test it with the switch in the “line” position.

If one side is dead/weak that proves that something is wrong with the turntable. If both analog channels work it doesn’t really prove anything one way or the other.

Thanks for reviewing. I plugged the analog connections (the RCA cables?) to my speakers, switched to the line position (it was already there), and both channels/speakers work. And then I noticed that Audacity was working too! All I did was plug in the RCA cables to the speakers. I had previously been listening on the computer or through my headphones. Anyway, I recorded three albums and I thought I had this solved. But then on my fourth album, there was no sound in my right speaker and I got the flat line again. I went into Mac system preferences and changed the sound output to USB Codec and viola it worked again. But then I couldn’t hear the replay on the computer. Anyway, all this to say, I think you must be right that this has to do something with the record player. I am giving up for today. Will start again tomorrow. Thanks for all the help.