I don't know what burner program you use, but on the mac, I use Roxio Toast which comes or came with a utility called Spin Doctor. This was effective in removing pops & some scratches. But you'd need to re-equalise to boost back the frequencies because it filters out the higher frequencies. Pops & cracks tend to be very high frequency & only last for a few milliseconds so they're often easy to find when viewing on an edit window. The quieter ones are difficult to get rid of though as are some other scraping type noises. Checking Audacity I notice it has click removal & noise removal. I'm not sure if they came with the program or were 3rd party downlds. It takes practice to learn to use those types of tools safely & knowing how much to add back when equalising.