Limiter effect glitch


I have run into a strange limiter effect while recording 24/196’000 vinyl rip on Audacity(latest, 2.0.3). it seems to limit the waveform from one side only(pic in attacement). I have seen this one before with my last turntable and when I changed stylus it fixed it. With my new Pro Ject Carbon Debut it seems to pick the limiter on sertain records (most of them). I tried to record with simple voice recorder (windows inbuilt) - no such effect (recorded with both simultaneously). The effect also is seen on Adobe Adition.

Any thoughts

Phono preamo: JET TC-720

That looks like a defect in your preamp or soundcard/interface. It sould be hard to do that accidently in software.

I tried to record with simple voice recorder (windows inbuilt)

What hardware is different? Maybe a high-pass filter would tend to hide the defect, but I assume there is no high-pass filter in Windows voice recorder software.

I have run into a strange limiter effect while recording 24/196’000

If it only happens at 24/196 you can use a lower resolution setting. That’s way-overkill for analog vinyl… It’s overkill for human hearing too! :wink:

I have seen this one before with my last turntable and when I changed stylus it fixed it.

I suppose that could be caused by a damaged/defective cartridge/stylus, but I’d be surprised if it only affected one channel… If the stylus hits some mechanical limit in one direction, I’d sort-of expect some “damage” in the other channel too. Plus, I think the RIAA equalization would change the waveform enough to “hide” the hard-limiting in the visual waveform.

If you zoom in really close on the waveform so that you can see the individual peaks, there may be a hint as to where the problem is occurring. If the peaks are cut off absolutely flat, then it is almost certainly “digital” clipping and so occurring after the A/D converter. If the peaks are “squashed” or otherwise distorted but not totally flat, then it is more likely to be occurring in the analogue realm - ie before the A/D converter.

My guess is that the pre-amp is overloading. There is no rule that clipping (overloading) has to be symmetrical - in analogue electronics it often isn’t. If your pre-amp is battery powered, check that the batteries are not getting low. If the pre-amp or turntable have level controls, try turning them down a bit - that left channel is precariously close to 0 dB on the positive going waveforms. It is safe to allow 6 dB of headroom (half the track height for the loudest peaks).

In the picture, the recording level appears to be a bit higher in the left channel, so the issue may not be only the left channel - it could be that the right channel is below the level of the problem.

Its usually on both channels and with some albums there is no clipping.

Here’s the thing with troubleshooting… You can NEVER know for sure what the problem is 'till the problem is solved. We can only help you guess. You have to change software & hardware until you find & fix the problem.

I say it’s very-likely to be a hardware electronics problem. If you want to test that hypothesis and hopefully narrow-down the problem, you’ll need to try a differnt soundcard/interface (or different computer) or a different preamp.*

If you are using a laptop with only a mic-input (no line-level input), that could be your problem. But, I’m inclined to agree with Steve and put my money on the preamp being the problem.

It comes down to starting with whatever hardware is easier or cheaper to swap. If you have access to another computer, it would be easy to try it out. Or you can get a PCI soundcard for less than $10 USD, but you might want a better soundcard if you determine that your soundcard needs to be permanently replaced. (Don’t get a USB soundcard for this experiment, because they usually don’t have a line-input, just mic-in and headphone-out.)

You’ve already tried different software and had the same problem with Audition, which would point-to a hardware problem. However, you didn’t see the problem with Windows Voice Recorder which makes the software experiment somewhat inconclusive (if you were using the same phono preamp & soundcard).


  • If the problem is in the soundcard/interface, you could potentially be fooled with a different preamp, a different phono cartridge, or a different record, if the output-level is lower and you never hit that “limit”.