Hi everyone,
I’ve searched far and wide for an answer to this problem. I’m sure it has something to do with a form of clipping, but I am not sure. Here goes (see and hear attachments):
I record vinyl with audacity and a small UA202 USB interface to my computer. When I listen back to some recordings, there are these unpleasant clicking sounds. Zooming in on the wave in the respective place, it seems that the wave just breaks down completely for a milisecond and then goes back to normal levels immediately. Also, these faulty recordings look like the top and bottom edges of the waveform have been cut off (i.e. they clip). But the levels don’t reach 0 db while recording — they don’t even seem to get that close. I’ve solved this problem by recording these discs at rather low volume, but I would still like an explanation for this phenomenon: Why does the recording clip and break down when it doesn’t seem to clip originally?
Thanks!
UA202 USB interface
What’s a UA202?
Koz
Do you have your music system AUX-Out connected to a Behringer UCA-202?
– Your USB interface doesn’t have a clean connection to the computer. Hub? Splitter? USB Sharing?
– The machine is paying attention to something going on that has a higher priority than Audacity does. Zoom? Skype?
–You’re trying to do live sound production with internet storage. Audacity hates clouds.
Turn off the internet. Disconnect the CAT-5 cable or shut down the WiFi. Restart the machine and try again. If you get something complaining bitterly that the world will end if you do that, then you may have found the culprit.
There is an Audacity setting that can affect gaps like this.
Audacity > Edit > Preferences > Devices > Buffer Length. Buffer length can be set by trial and error and the problem comes when the continuity doesn’t always break. You’re never sure if you did something or if it solved itself for a while.
It’s insanely handy if you can make it break all the time, or make it worse. We can work backwards from that.
Koz
Hi Koz, thanks for taking the time. Yes, it’s a Behringer USB Interface set up like you guessed, sorry for not clarifying that right away.
Changing the buffer length around didn’t do anything. I disconnected the internet and didn’t have any other programs running and the problems persist. I changed the USB cable, too. It runs directly into the computer, no splitters involved, and the temporary data is stored on the computer, not online.
I also was wrong in my first post: The problem persists even at lower volumes. The breakdowns appear when a lot of signal is coming through, i.e. when a bass drum hits. Weirdly (coincidentally), I’ve only had this issue with records at 45rpm (which are cut louder). I used to run an aux into the Line in at my old PC, which I don’t use anymore. Never had anything such as this, so it has to be related to the USB interface. Maybe there’s an overload of signal within the interface? The recording seems to be limited when I record the respective discs. The wave looks normal when I record, but when I import the .wav into Audacity, it looks clipped around the 0,5 marks.
I don’t really know how to make this worse. Volume, buffer length, etc. don’t seem to change the outcome much.
When you record the work the blue waves are much taller than they are later, after you Export the WAV files, open them, and play them back? No effects, filters, or corrections?
Is the green USB light on the UCA202 on?
Has it ever worked?
Koz
Nope, no filters or anything of the sort. The recording is faulty from the beginning, but it doesn’t look as stunted as it does when I re-open the file in Audacity.
The USB light is on. It has worked, and it even works perfectly with different records that I record into Audacity on the same day/right afterwards.
With respect to the illustration where the blue waves are sliced off at 50%. The next time you record it’s not sliced off at 50%? Are the waves ever sliced off lower than 50%?
Koz