[recordist]

I would like to use Audacity to apply a uniform increase in the level of some WAV files. Is this possible? I would like  to increase the quiet and loud parts of  the recordings by the same factor to compensate for the fact that I have recorded some tracks at too low a level. I currently have to turn up my amplifier to very high levels to play these tracks. I believe that if I am having to use the upper range of the volume control on my amplifier this may be introducing unecessary levels of distortion compared to an average level track player back through the same amplifier and speakers. How will I know how much increase to use without clipping the high volume levels?

 

[Ro-amp]

Go to effect-> amplify- > there you can choose the level of amplification in +/- dB, I think it will automatically default to the highest level without clipping (confirmed, make sure the allow clipping box is not ticked), if you want higher level tick the box and then if use the hard limiter in the Effect section.
Clipping will show as red bars
Cheers

 

[Slogra]

I believe what you are looking for "Normalize". This will increase the volume to the highest peak. Note that this will not even out the volume of different tracks because the average volume of a track is not the same as the peak of a track (if you know what i mean), but i don't think you are looking for that.
Quote:

I believe that if I am having to use the upper range of the volume control on my amplifier this may be introducing unecessary levels of distortion compared to an average level track player back through the same amplifier and speakers.

I don't believe a low volume track will ever hurt your amp/speakers, even if you set the volume control to quite loud.
The only problem comes when you play a really loud track after a really soft track .
 
Btw don't take nowadays CDs volume as a standard or example. Most nowadays CDs are WAY too loud and clipping all over the place! They go way beyond normalize and the sound is often completely destroyed. That is probably not what you want.