Waveform Clipping

[able211]

I cannot get the wave envelope inside the levels. It worked fine for a few LP's that I recorded, now I get considerable clipping of the wave form, and turning down the input doesn't do anything. I'm using 1.3.beta with Vista.

[steve]

If it's a USB turntable, have a look underneath the player to see if there is a volume control hidden there.

[able211]

No, there isn't a volume control on the usb turntable, which is a Tevion make. I've un-installed Audacity many times, without success.

[steve]

Uninstalling Audacity won't fix the problem because the problem is not in Audacity. The problem is that either the input signal is just too hot (too big a signal going into the Analogue to Digital converters) or Vista is messing with the sound. The first of these can happen if the vinyl has been recorded very loud, for example some DJ mixes, and the only solution to that problem is to turn down the gain control on the record player (if it has a gain control). Let's hope that is not the problem.

The other option is also very common because Vista (and Win 7) often assume that any USB audio device plugged in is a USB microphone, and so set the recording level really high. To fix this problem you need to go into the Windows Sound Card settings.
Right-click over the speaker icon in the System Tray > Recording Devices
Right-click on the USB device, click Properties then the Levels tab and adjust the volume slider.
There is also an option somewhere in there for setting the recording quality. It should be set to "44100 Hz CD Quality Stereo".

[able211]

Thanks for reply. I can reduce input that way, but I then get a "squaring off" of the waveform, in other words, clipping.

[steve]

I don't think there's much we can do about that as the clipping is occurring before the signal gets to Audacity. However, I'll ask for a second opinion in case anyone else has any ideas.

[Trebor]

Maybe a driver problem ?

Tevion USB TT manual - driver.png (6.75 KiB) Viewed 1538 times

[/url]
http://www.unisupport.net/download/5056 ... ual-EN.pdf

You may wish to disconnect from the internet when using the turntable for two reasons ...
#1 programmes connecting to the internet may momentarily interrupt Audacity when you are capturing your vinyl, causing tiny gaps in your recording.
#2 Windows Vista may automatically download another USB driver via the internet, which could be the cause of your clipping problem ...

In most cases, Windows already has the necessary driver installed or can automatically download it from Windows Update. If Windows installs a device driver automatically, you'll see a notification indicating the device is ready to use.

If a device works fine but then fails after you update its driver [or driver is updated automatically] , the problem is with the new driver. Roll back to the previously installed driver. For instructions, see Restore a driver to its previous version.

http://windows.microsoft.com/en-US/wind ... SB-devices

[Gale Andrews]

USB turntables almost never come with special drivers and if there are none on the CD that includes Audacity then I doubt any special drivers will be installed. If that's the case, all Windows will do is install the device so that it appears in Windows Device Manager and register Microsoft generic USB Audio class drivers to work with the device. You can always look in Device Manager in the Windows Control Panel (right-click over the device > Properties) to see what driver is being used.

I doubt there will be anything simple you can do if you want to use the USB cable. If the cartridge is replaceable you could take it to a hifi shop and see if you can get a lower output cartridge. If the cartridge is ceramic (cheapo USB turntables may still use those) it will have a high output. Magnetic cartridges will be lower output (and better quality).

Otherwise you can try taking the RCA leads from the turntable, plug them into an RCA stereo > 1/8 inch TRS adaptor, then connect the adaptor to line-in of the computer and set Audacity to record from line-in. Many users in this position get an acceptable result that way and usually Audacity would be able to control the input directly too.

Or just take the turntable back and get an Ion USB turntable. Most Ion models have a gain control and have a more reasonable output level.



Gale