Now that we all have thousands of songs on our hard drives, I'm tempted to import all my CDs onto my Mac and store the originals in a cool, dry place. While I have no problem saying goodbye to my discs, I won't sacrifice sound quality. I rip all of my tracks using hi-fidelity formats, and I circumvent my low-grade computer speakers by hooking my Mac up to the living-room stereo system. That's where the roadblock comes—when I connect the computer to the stereo, my tunes sound faded and distorted. How can you play music off your computer without it sounding like a faded cassette tape?
The trick is to bypass the built-in sound hardware. Your desktop's soundcard, not digital file compression, is the weak link in PC music. The audiophile writer Michael Fremer explained to me that out-of-the-box computer audio sucks for two reasons. First, the digital-to-analog converter—a circuit that translates binary bits into old-fashioned voltage—is low grade in most computers. Second, the converted analog signal is subject to all kinds of electronic interference from your computer's other hardware. That adds hiss, hum, and whiny robot noises to your music before it reaches the output jack.
Newer Macs and upmarket PCs solve the problem by punting on it. Both computers provide a fiber-optic output jack that runs a digital signal all the way to your home-theater console, where the digital-to-analog conversion gets done much better. If your machine or your stereo doesn't have a digital jack (and most don't), you're not completely sunk. Fremer's advice: If you can't splurge on fiber optics, at least relocate the digital-to-analog conversion process from the hostile environment inside your computer.
I put his counsel to the test by trying out a variety of add-on hardware devices for the past three months. It doesn't matter how old, slow, or crappy-sounding your PC is—these gadgets will bypass its internal hardware completely. Each unit connects to your computer via a USB port, which also provides all the power they need. For maximum bliss, run a USB extension cable as close to your stereo or theater inputs as possible. Park the USB audio converter there, then run a short analog audio cable the rest of the way to your hi-fi gear. This will reduce the amount of interference and degradation the analog signal suffers en route.
I ended up focusing on three simple adapters. Each of them noticeably improves your stereo sound without turning into a science project, and they all work on desktops and laptops, PCs and Macs. The only difference is price. Here's the best sound you can buy for $40, $100, and $300.
Size: Resembles a sand dollar.
Sound quality: 3 out of 5.
Best feature: No need to read the instructions.
Worst problem: Phone and Wi-Fi interference.
The iMic offers a cheap, instant upgrade for any computer. There's no software to install or switches to fiddle with—just a USB plug at one end and an eighth-inch audio jack at the other. Plug it in and your computer will recognize the device immediately. Then, find the control panel for sound output and make the iMic the default device. Once that's done, just use the iMic's output jack as you would use the headphone or line-out jack on your computer.
The iMic addresses Fremer's two gripes: It's got better digital-to-analog conversion than most computers, and it's less prone to computer-induced noise. The built-in amplifier is certainly strong enough to drive a pair of headphones at a reasonable volume. But the iMic doesn't deliver the same dynamic range (the span between the quietest and loudest passages in a piece of music) as the pricier units below. Both iMics I tested also sputtered loudly whenever my cell phone rang or my laptop's Wi-Fi card fired up.