Okay so I have successfully digitized over 500 LPs to date using Audacity. Now all of a sudden the top and bottom of the signal appears clipped. I didn’t make any intentional setting or equipment changes. Please see attached pic. Does anyone know what setting is doing this?
There’s no volume control on the turntable. However, I did find that the RCA cable that connects from the Vincent phono pre-amp to the turntable had a loose connection at both ends. Will try again tomorrow night.
So it looks as though you have a Vincent PHO 701 Phono Preamplifier MM/MC or similar.
When digitizing LPs, an analog signal is converted to digital at one location. So ask yourself, where in your system is this occuring? Since the output of the turntable is analog and the output of the USB cable is digital, that means the place to look is within your preamp.
So while it is possible that a poor connection in your RCA cables (or lack of a ground wire) could be contributing your your issue, it is more likely that there is a level issue.
This clipping could be caused for instance if you have a MM (moving magnet) cartridge with a high output and your Vincent is set for a MC (moving coil) cartridge which could typically have a lower output. Then again, if you have a crystal pickup system or if the turntable already has a built-in preamp then “an external phono preamplifier is not necessary.” (see 701 manual, page 28) and this could cause the clipping that you see.
So, make a note of the position of the MM/MC switch on the back of the preamp, then change it to see if this corrects the issue. Note that there are additional adjustments at the bottom of the unit (see pages 30-31) that have the potential to correct the clipping issue (no promises).
It does look like a hardware problem… Maybe it’s time for you to tell us about your hardware…
Okay so I have successfully digitized over 500 LPs to date using Audacity. Now all of a sudden the top and bottom of the signal appears clipped.
With the same hardware? What were your levels previously? Did they ever go above -6dB (50%)? Some records are louder than others so, is it possible this is the first time it’s happened? Or the 1st time you noticed it?
The digital-to-analog converter will normally clip at exactly 0dB so it looks like the clipping is happening before the signal is digitized.
Jademam nailed it on the head! Thank you sir, quite impressive. The MM/MC switch was depressed to the MC position. I must have inadvertently depressed it when re-securing the RCA jacks and ground wire on my PHO-701 while diagnosing another issue which I will post in a new thread. Originally I had set it to MM to align with my Ortofon Bronze cartridge.