To input music from a standard turntable or phonograph to a computer, the sound must pass through a preamplifier. This is where your stereo receiver comes into use. The amplifier boosts the signal from the phonograph to line level so that it is suitable for input into the computer. The amplifier also corrects something called an RIAA curve, which is a standard used by vinyl-record makers to equalize high and low pitches on every recording since 1955.
Connect the turntable to the receiver through the phonograph "in" jacks, as you would do if you were planning only to listen to records. Connect the receiver to the computer through the receiver's "line out" jacks and the computer sound card's "line in" jacks.
A USB turntable connects directly to the USB port on your computer. USB turntables have internal preamplifiers. Some models of USB turntables are able to digitize the audio and save it onto a CD or SD card.
There are a number of different software products to record and convert the audio into a digital format. Audacity is an open-source program, written by a team of volunteer developers, that records the audio signal and saves it in several different file formats. Audacity is a full-feature audio editor that lets you edit the audio file to remove excess noises and pops. You can even add effects like echo, fade in or out, and tempo changes.
Adobe Audition, a later incarnation of Cool Edit Pro, and FL Studio, also known as FruityLoops, are popular commercial-recording software programs. You can edit and manipulate the new sound file with these programs. Take advantage of any free-trial-offer periods to test the programs. Experiment with different software programs to find the one that best matches the condition of your albums, hardware configuration and your comfort with the program interface.
The process is time-consuming and often will require trial and error to get the settings correct. Your best efforts may never yield the sound quality you expect. You will get the most from the process when you transfer rare titles and albums that hold sentimental value for you. It is also a less-expensive alternative to re-purchasing your album collection in digital format. Any time you spend digitizing your music is also time you spend listening to your music, and that may not be such a bad trade.