“I want to make CD’s out of some old vinyl records, but when I plug a turntable I borrowed into my computer’s sound card the output is very weak and sounds terrible. What’s wrong?”
Most phonographs, or record turntables require a phono preamp be used between them and any subsequent audio gear because output levels of turntable cartridges are extremely low. Further, not just any preamp will do. You usually need a special phono preamp because it also has special equalization, known as RIAA equalization, to compensate for the way records were originally equalized in mastering. You can try other things, but you’ll find that there really is no substitute for a proper phono preamp if you want your records to sound anything close to how they were intended to sound.
Until a few years ago most stereo hi-fi receivers had a phono preamp built in (for obvious reasons). Nowadays it is increasingly likely you will have to buy one separately. There are units available from outfits such as Radio Shack, and some hi-fi dealers. Some pro audio equipment includes a phono preamp as a convenience for circumstances such as yours. One such device is Tascam’s CC-222 CD recorder, which is a great buy for those wanting to easily make CD’s from LP‘s.