Recording Vinyl

[simon]

Bit of a long shot but I thought I'd ask

I've tried to record some vinyl on my laptop using Audacity so I can burn a CD to play in the car, but there's something not quite right. It's a long time since I last did something like this using my old desktop system and the soundcard software and it worked well enough then.

But whilst I have sound being recorded through the laptop's microphone input there's an odd waveform that sounds like a clicking noise. This happens when the phono stage is connected directly to the laptop with no record playing, see the first screenshot.

When I play a record the music is superimposed on this clicking noise, and there seems to be some distortion on it too, or perhaps it's just the underlying problem that's cocking the signal up? See second screenshot.

I'm using Audacity 1.3 beta and the laptop's internal sound card is a Realtek.

Anybody got any ideas?

[colin.hepburn]

Hi Simon
Yep I think the phono stages output will be on the high side I have a usb device I plug into the computer usb socket and I then plug the input of this device into the tape out on the amp so just try plugging the computer into the aux/tape out off the amp

[Andrew]

I tend to use an analogue volume control as well as the phono, to get the levels right, that is, of course, assuming too much volume is your issue.

Andrew

[Mike H]

The usual problem I find is the laptop's power supply adds a buzz on the signals if anything earthed is plugged into it. Hence I use isolation transformers in the audio link.

But also see above, input level is easily over the top without a means of controlling it.

[simon]

Hi Simon
Yep I think the phono stages output will be on the high side I have a usb device I plug into the computer usb socket and I then plug the input of this device into the tape out on the amp so just try plugging the computer into the aux/tape out off the amp

Hi Colin,

I don't have any tape outs, I'm a bit more, er, hairshirt than that . Not sure about the input level being too high - I reduced the level of the soundcard and the recording level in Audacity so that it wasn't saturating. But I get the peculiar clicking noise with no signal from a record...

[simon]

I tend to use an analogue volume control as well as the phono, to get the levels right, that is, of course, assuming too much volume is your issue.

Andrew

I could try running it through the passive pre, but I wanted to keep it as simple as possible. I'll give it a whirl tomorrow if I get chance.

[simon]

The usual problem I find is the laptop's power supply adds a buzz on the signals if anything earthed is plugged into it. Hence I use isolation transformers in the audio link.

That's very interesting Mike, I'll try running it from the battery tomorrow too.

[colin.hepburn]

I have this software but I haven't used it yet but I see it has click track and other settings under the generate tap could it be one is set to on of something
Just an idea a setting you may have mist

[The Stratmangler]

Any chance of posting an audio clip of the interference somewhere on't t'interweb ?

You might need to open a freebie account here to do it www.mediafire.com

[Mike H]

The usual problem I find is the laptop's power supply adds a buzz on the signals if anything earthed is plugged into it. Hence I use isolation transformers in the audio link.

That's very interesting Mike, I'll try running it from the battery tomorrow too.

Yep turn the mains off and it all goes quiet just like that. Actually that's how I used to do it before sorting out the audio link.

And before anyone asks this applies to both my notebooks using completely different USB audio adaptors. Actually the older notbook is worse for the noise so probs depends how the SMPS mains adaptor gizmo is designed as well. And there's no mains earth on these.

 

[simon]

Hmmm.

Doesn't make any difference whether the laptop is plugged into the mains or not, but there was a completely different waveform tonight - much more irregular, random almost. No idea why this might be.

But I tried taking the signal from the output of the passive pre to the laptop (rather than direct from the phono) and it seems to work... The difference is a selector switch and a stepped attenuator. But with the volume turned up full to maintain the signal it seems to works... But why I don't know. I'll try recording a side later and see what happens.

Any chance of posting an audio clip of the interference somewhere on't t'interweb ?

I was going to but a 12s clip is over 2MB! S'pose I could convert it to MP3 perhaps.

[The Stratmangler]

Any chance of posting an audio clip of the interference somewhere on't t'interweb ?

I was going to but a 12s clip is over 2MB! S'pose I could convert it to MP3 perhaps.

It took less than 2 minutes to upload this http://www.mediafire.com/?8fq440e6w3u26mu , and my DSL is not the fastest either.

Chocolate Noddy to the first one to post the time signature of the title track of the album the track is from.

[simon]

Blimey that was quick. It uploaded over 4MB in less than a minute.

Clip of "silence" here: http://www.mediafire.com/?sh4opfuixwyaqy9
Clip of music here: http://www.mediafire.com/?giqgv7mqh11x9z8

Hope it works...

[simon]

Chocolate Noddy to the first one to post the time signature of the title track of the album the track is from.

You're having a giraffe right? Odd bits reminded me a little of The Flaming Lips - who (or what) is it?

[pre65]

4-4 ?