Comparing two CD players uses our Audio Control Center, in particular our model 457, and optionally the remote control unit which is model 458. Real-time comparison simply means you can switch back and forth between the two CD players using the same CD. You can, of course, buy two identical CDs but the "fair use" laws in the United States let you make a backup copy of any CD that you personally own. If your computer has a CD writer, making a copy is simple. See the note below. (I don't know about the law in other countries so perhaps you should check it out.)

Connect the components as shown in the diagram using stereo RCA cables. Since this is not a permanent setup, just arrange the pieces fairly close together on a table or where ever is convenient.

Connect the stereo outputs of the two CD players to stereo inputs 1 and 2 on the rear panel of the model 457 with a pair of short stereo cables. Then, connect the 457's output #1 to your power amp's input. You can switch between inputs 1 and 2 using the rotary switch on the 457's front panel, or optionally, you can plug the remote control unit into the 457 (on the rear panel) and then use the switch on the remote control. Using the remote control has the advantage that you can sit in a comfortable listening position when doing the switching between players.

This kind of comparison can be very useful. Suppose a friend of yours has just bought a new CD player. With this setup you can easily and quickly compare his/her new one with yours. Can you hear a difference? If so, you may decide to upgrade. I have compared a new Pioneer model with a Teac that's about thirteen years old. I can clearly hear the difference on some (but not all) CDs. (The Teac, of course, won't play anything except CDs so I can't make a comparison on SACDs or DVDs.) However, if both players will handle the newer media you can make the comparison providing you have two identical SACDs or DVD-Audio discs. You can copy SACDs, like you would copy an LP record, but you can't make direct copies as you can with CDs. DVD-Audio discs can be copied but the software to do it is a bit specialized.

NOTE on copying CDs.
You can easily copy a CD by inserting it in the CD writer drive in your computer (CD writers are also readers), and then starting a "ripper" program which copies each CD track back to individual wave files on your hard drive. I use the Dart CD-Recorder (which is also a ripper) which came with Dart XP Pro (an audio restoration program). But there are many rippers available. A Google search on "CD ripper" found nearly two million English references: freeware, shareware and low-cost commercial software. So take your pick and just follow the instructions that come with your choice.

For "burning" the new CD, I like Easy CD Creator (version 5 or above). You may already have it as it often comes bundled with a CD or DVD writer. If not, you can order the latest version online from: Roxio. Just insert a blank CD-R in your writer and start the program (it may start automatically). Point to the folder containing your trackxx.wav files and add them to the record list. Then press "record". It's best to choose the lowest recording speed available (2X if possible) as this gives the best quality recording (because it reduces the sample-to-sample time jitter.)

The last step is making a CD label and a label for the jewel case spine. I use CD LabelMaker Easy. It's simple, easy-to-use and free. You can download it from: Memorex. CD labels and an easy-to-use applicator are readily available from any Office Max, Staples or other office supply store.