Noise when converting vinyl to digital

[kozikowski]

I split this into its own topic. Koz

This is similar, but different from the Sudden Noise post. My equipment includes: Audacity1.3x (beta), a MacBook with OS 10.4.11, Behringer UFO202 preamp (new) and a Panasonic Techniques SL20 single play turntable with diamond stylus tracking less than 1.5 g (1980s model that has a flawless playing record on a high end stereo system with Advent speakers).

I have been recording with Audacity for about 2 weeks and the first tries were with the 1.25x version. I have been recording both popular vocal and classical records of good quality, freshly cleaned before recording. The first 3 or 4 sessions were learning but went reasonably well.

Then yesterday I was recording some monophonic vocals of country/western variety with tracks from 1.5-3.5 minutes. I was using 16 bit setting on Audacity 1.25x and saving tracks as .aiff and mp3. Here is the experience: The first 2 tracks will record perfectly and then the third track will develop a buzz that starts off as a few crackles and then develops into a buzz that strongly competes with the music.

I tried noise removal and it muffled it a little but to no avail. I then downloaded new copy of Audacity 1.3x and the same thing happened, first two tracks perfect then noise from the third onward. I have tested this out with both classical and popular. Can you help me? Thank you....Lou Abbey

[kozikowski]

Just to connect the dots... You can't just plug a classic, high quality turntable into a UCA202. A classic turntable has no RIAA preamplifier like the USB turntables do. The music will be seriously peaky and gutless. The music on vinyl is not perfect. It's intentionally distorted according to some very firm rules. You need to restore the music before you can listen to it.

Phono Preamplifier
-- Two very nice phono preamps in actual use.
-- Honorable mention to the Hafler HD-101 preamp, no longer made.

http://www.phonopreamps.com/tc750lcpp.html
http://www.artproaudio.com/products.asp ... =13&id=109

You can cure this with Audacity equalization tools, but it's usually far better to use a "Phono Preamplifier" between the turntable and the computer.


Now, the problem you posted about. All of the questions in the other post apply. How full is your hard drive? Go > Computer > System Drive > INFO.

I think the first level maintenance would be to unplug and replug the UCA202 several times to make sure the connection is OK.

Then disconnect the turntable from the UCA202 and start a recording. Go for ten minutes -- or as long as it took the distortion to arrive the first time. Do you still get increasing noise?

Koz

[steve]

You can't just plug a classic, high quality turntable into a UCA202

The original post says "UFO202" (which unlike the "UCA202" does have a phono pre-amp built in).

[kozikowski]

Oops. 'Scuse me.

Koz

[billw58]

Is the UFO202 connected directly to the Mac, or through a hub? Direct is preferred.

Could you post a brief sample of the noise (a few seconds) in FLAC or AIF format?

-- Bill

[Lou Abbey]

Thank you for the quick reply. I can probably eliminate the preamp completely by routing the turntable through my stereo amplifier and then connecting to the computer. Your comment stimulated this idea and I have looked through my manuals and I can connect from the amp to the computer audio input port. I will try this tomorrow. This way I can eliminate the USB connector and the low level preamp, two potential problems at once. If someone can tell me how to post an mp3 file I can let you hear the buzz. Thanks for your active response....Lou Abbey

[kozikowski]

Maybe we don't need that.

Did you hook up the turntable ground lug? Classic turntables had three wires, not two. There was a thin black wire that formed the shield and ground for the turntable. Without it, the turntable will hum and buzz.

Koz

[waxcylinder]

As Koz just said - I note from looking at the UFO202 on the Behringer website that the UFO202 has a ground connection - were you connecting the little black wire from your deck to that grounding post?

WC

[Lou Abbey]

Yes, the ground has been connected all along. I tested it with ground off, and a different, louder, buzz was apparent and disappeared with reconnection. The noise that I am experiencing is more diffuse and integrated with the recording, like hard rain on a tin roof while you are trying to carry on a conversation. It does not appear until about 5 minutes or so into the session, so usually track 1 is clear. This makes me think it may be related to something that has to heat or function for a while before it malfunctions. thanks again for this conversation. It gives me hope....Lou Abbey

[waxcylinder]

Sounds more like a poor USB connection then - which is why Koz was recommending plugging and unplugging earlier. Can you try a different USB port (not a hub)?

WC