I am digitizing my LPs and have got Audacity working (recording) but I am not sure where to set the input level. I am using a USM photo preamp with a gain adjustment. Thanks.
Depending on your hardware (soundcard, etc.) you may not be able to adjust it.
In the current version of Audacity the recoding level is combined with the [u]recording level meter[/u] and it shows-up as a little box that you can drag left-to-right.
Generally you need to adjust the analog level before it’s digitized, and with most USB interfaces you can’t adjust the recording level (unless it has an analog knob). Usually the slider won’t move or it doesn’t have any effect.
If the signal is too hot and you get [u]clipping[/u], lowering the digital level after it’s clipped doesn’t remove the distortion (but it can “hide” the clipping from Audacity).
The main thing is to avoid clipping. The analog-to-digital converter clips at exactly 0dB. The usual recommendation is to shoot-for peaks between -3 and -6dB, and then you can Amplify in Audacity after recording.
As long as you’re not clipping it’s not THAT critical… Nothing bad happens when you get close to 0dB and -12dB is probably OK. If you can’t get over around -20dB that might be “pushing it” and it also might be an indication of a problem. (-6dB is 50%, -12dB is 25%, and -20dB is 10% of the digital maximum.)