- Category: Tech Soup
- Published: Monday, 09 June 2003 00:00
Here's the trick. The frequencies that are added and removed are not random and they don't change from record to record. (Except for 78s that had no equalization) In fact, the equalization curve, is a standard developed by the RIAA. So every record made since about 1955 has used the RIAA equalization curve. And stereo receivers with phono inputs should more or less add and remove the right spice of frequencies to accurately reproduce your music.
If you were to try and play records without a proper preamp, such as using a tape or CD input on a receiver, the levels would be extremely low, hissy, and lack bass frequencies. If you were to plug directly into the mic jack on a sound card, the level might be acceptable but the sound would still sound hollow, hissy and lack bass.
What's so cool about a phono preamp is now you don't have to haul in your old clunky receiver just to play records into your PC. Essentially they have reduced the clutter factor from a full size stereo component to a pack of cigarettes. We first reviewed a unit from Terratec a while back but now several manufacturers make these little gadgets.
I've been using an Adcom preamp with my trusty old Technics turntable and Grado cartridge to record my records. It was a bit of a hassle because I had to run an extra set of patch cords from the preamp to my mixer and then to my computer. The Adcom preamp sounds pretty great. I have to say it beats most of the new preamp only boxes I've tested. However, with a little EQ and sweetening in the PC you can get away with the more convenient dedicated preamp.
A simple phono preamp black box works with all moving magnet pick ups and usually includes selectable input capacity and output amplification to fine tune the signal for your particular setup. These are powered through the game port or USB port on your PC. Then you simply plug your turntable into the Preamp and the Preamp output into line input on your sound card. Next open the mixer panel of your sound card to make sure the fader for the channel you plugged into is up. Any standard audio software can be used to record your records. You'll get the best results with a package that has good metering for setting your recording levels, such as Sony's (Sonic Foundry) Sound Forge.
As with any audio chain all the links have to be clean. My records are not in the best shape. I could use a new cartridge and my turntable has seen better days. However, with a little noise reduction and some sweetening in T-Racks I'm bringing my old records back to life. So if you are a vinyl junkie now you can get down to business cleaning up your old LPs and making those "best of" mixes you've promised all your friends.