Audacity Forum

Trying to record from vinyl (through line in of an external sound card) and getting a quiet but annoying kind of ringing noise. It must be coming from the turntable in some way from the sound of it, and the fact that I don't get it when recording from tape. However, when I listen to the recording, even through the soundcard output the noise just isn't there, it only appears when I actually play back the audacity recording.

Any ideas?

Recoding of the start of a record:
http://dl.toofiles.com/vaaoje/audios/noise.wav

There appears to be a ringing around 3900 Hz that repeats once per revolution of the disk. What turntable and cartridge are you using? Is anything loose on the turntable? Is the cartridge securely attached to the head shell? How are you connecting the turntable to your computer (through a pre-amp, etc.)?

-- Bill

It's a Thorens TD166 MKII with Grado cartridge going through a project pre amp then into the amp and a line out to the soundcard (creative x-fi).

I've taken the plate off and checked everything, can't hear anything rubbing or making a noise. Cartridge is on firmly, but looking at the record there is a tiny warp - not large enough that it should effect anything and I get the same noise on any record I try. I know it must be coming from the turntable but it doesn't appear when I just listen to a record normally, only when I listen to a recording I've made using audacity. Could I be amplyfying a tiny problem by running it through all the stages?

Could I be amplyfying a tiny problem by running it through all the stages?

Stages such as?

Koz

The spectrum of the 'noise' sample looks like a comb ...
this can be caused by feeding back a delayed version of the signal.
Look for sources of feedback, e.g. check you are only recording the turntable, (the not turntable and the output of Audacity).

The feedback could be mechanical (rather than electrical) via the turntable arm, (adjust the arm counter-weight),
However that type of feedback would be audible on the output from the turntable, not just on the recording.

If loudspeakers are being used (rather than headphones) there could be acoustic feedback ...

adjustable rubber-damped feet ensure that the Technics SL-1200 series are well-insulated against acoustic feedback

http://en.wikipedia.org/wiki/Technics_S ... _strengths

The age / type of turntable mat may be to blame ... http://groups.google.com/group/rec.audi ... 0999?hl=en

@Trebor:
Edit the recording to remove the vinyl ticks (choose to retain a section between the ticks), apply a high pass filter 200 Hz 48 dB/octave, then amplify. You can clearly hear the ringing coming and going every 1.8 seconds. If you do a plot spectrum at this point you can clearly see the peak at about 3900 Hz.

As for why the OP can not hear it while recording, it could be that he can't turn it up loud enough while recording to hear it without causing feedback ... or some other effect. My guess is that the sound is coming from the turntable. It sounds like something scraping on the platter every so slightly - but that doesn't make sense as you'd think the platter mat would damp it out. In fact I can't duplicate it with my Thorens TD160.

I'm mystified.

-- Bill

billw58 wrote:... you'd think the platter mat would damp it out.

Maybe the (25 year old ?) rubber has gone stiff with age.

billw58 wrote:... If you do a plot spectrum at this point you can clearly see the peak at about 3900 Hz.

If all else fails can notch out 3909Hz ...

Seems feedback was the problem. Unplugged the input to the souncard from the amp while recording and it's perfect now. Not sure why it's fine to leave it all plugged in when recording from the tape deck but not from vinyl, or why I couldn't hear yje noise when listening to the recording output, but I won't lose any more sleep over it.

Thanks all for taking the time to look and reply.

The turntable system is a pure mechanical process. The disk revolves and causes the needle to vibrate. Anything else in the room causing vibration can make the needle vibrate, too. It doesn't have to be coming from the desk underneath the turntable. Loud enough sounds can cause the record itself to vibrate. That's deadly.

Tape is magnetic not mechanical, and as long as the tape is moving past the heads, it doesn't matter how loud your speakers are. Try just turning them down or using headphones.

Koz

When I was a kid the only music source we had at home was a tape recorder/player.
My uncle had a turntable and a big collection of LP's. Sometimes he would land us the turntable and some records and we (my father and I) would make a... eerrrm... backup copy to tape of the records.
The room where he had the equipment had a window to the street.
I remember one time, when we were in the middle of such a process my mother went out and passed in front of the window and decided she needed to get our attention so she knocked on the window with her keys and shouted something... Later when listening to the recorded tape we could clearly hear the key hitting the window and my mother's shout (not so clear as the knocking).