Radio Shack Optimus CD-3400 portable CD player Greenberg

Corey Greenberg reviewed the CD-3400 in July 1994 (Vol.17 No.7):

Forget ham radio, forget Paul Revere, forget the Information Hershey Highway—when it comes to spreadin' the news, there's no faster service than the Audiophile Grapevine. You want next-day delivery? Call FedEx. You want to get it there positively absolutely in a matter of minutes? Call an audiophile and pant about the latest breakthrough o' the week. It helps if you drop a name or two, but you don't even have to go that far—by the time the news travels across the country (a matter of minutes), every reviewer/dealer/pimp in the game will have already heard the thing and be ready to jump out a window, they're so pumped.



"HEY!! You gotta hear this new thing everyone's going nuts over!! It's way better than anything out there, and it only costs fifty bucks!! Noted Guru heard it, and he can't believe how insanely good this little thing is!!"

"Wait a minute—I'm Noted Guru, and I haven't even seen the thing yet!"

"Er...what number is this?"

Which brings me to the latest Audiophile Grapevine Special: the much-discussed RadioShack Optimus CD-3400 portable CD player. When a certain Noted Guru called me and said that this little $179.99 thingie was the first digital source he'd had in his system that sounded like music, I said, "Hmmm." When I heard that some of the NY Audiophile Society members were throwing the little RadioShack up against the likes of Krell Digital and preferring the RadioShack, I said, "Say what?!"

As the calls came in from all over the audiophile map, the testimonials got wiggier and wiggier: So-and-so heard it and gave birth to a mutant half-cow/half-baby; the reason it sounds so great is cuz it's really a hyper-tech Mitsumi CD-ROM drive that somehow found its way into a RadioShack portable CD player; if you listen to it long enough, it cures diphtheria; Rabin sent one to Arafat, and now they're engaged to be married; Bob Dole got one, and now he just sits in his office listening to Moby Grape CDs and flashing the peace sign at startled aides.

It all sounded too good to be true, and definitely too incredible to ignore. If this cheap RadioShack portable really did compete with the best high-end digital gear, it'd be the ultimate Real World CD player—portable or otherwise. The raves were coming in fast and furious, so I called Tandy and had them ship a CD-3400 so I could hear what all the fuss was about.

Technology: Unlike most portable CD players, the plastic-cased CD-3400 features a digital output in addition to the jack you plug your headphones into. The line-level outputs appear on a stereo 1/8" minijack—the same size as the standard Walkman-style headphone jack—and the S/PDIF digital output appears on a mono 1/8" jack.

What's that? Your kilobuck Audiophile-Approved digital cable don't got no 1/8" plugs? RadioShack sells an RCA-to-mono-miniplug adapter (part #274-378) as well as an adapter with a stereo miniplug on one end and a pair of RCA jacks on the other (part #274-369A), so you can hitch the CD-3400 up to your system with your own interconnects; I have no idea what this does to the impedance of the termination, but the adapter did allow the CD-3400 to lock with all the digital processors I had on hand.

The CD-3400 takes four AA batteries—twice as many as some portables. And if you want to use an AC adapter, you'll need one that supplies 6V DC on the center pin at at least 500 milliamps—quite a bit beefier than what most portables require in the way of juice. Again, RadioShack comes to the rescue with their own 6V/700mA AC adapter (part #273-1655), for 17 clams.

Internally, the CD transport is indeed a Mitsumi part—the whole player is apparently an OEM unit built by Mitsumi for RadioShack. I wasn't able to find out whether or not it's really a CD-ROM drive, but it certainly doesn't look as heavy-duty as any of the CD-ROM drives whose guts I've gandered. Digital conversion is handled by a single-bit NPC DAC, the SM-5817AS, which includes its own 8x-oversampling digital filter. As far as analog audio circuitry goes, yo' guess is as good as mine—the ant-nut-sized surface-mount op-amps didn't look at all familiar to this op-amp hound.

The CD-3400 has one feature you should definitely ignore: a four-position EQ circuit which applies treble boost, bass boost, both, or neither to the headphone output (but not the line output). Unless you hate yourself, choose neither.

System: I listened to the CD-3400 as a stand-alone CD player via its headphone jack, as a line-level source via its line-out jack, and as a digital transport driving the various processors I had on hand. For headphone listening, I used the killer Grado SR60s—the $69 marvel I reviewed last month. I also compared the CD-3400's headphone outputs to the sound of its line outputs feeding a HeadRoom Supreme portable headphone amplifier. I used RadioShack's #274-369A stereo RCA-to-miniplug adapter to connect the CD-3400's line-level outputs to my He-Man reference rig with a pair of Kimber PBJ interconnects: Audible Illusions Modulus 3 preamp or my homemade buffered job; Aragon 4004 Mk.II amplifier; Theta Data II transport and Generation III processor; NHT 3.3 speakers; Kimber KCAG interconnect and 4AG speaker cables; everything, including the RadioShack AC adapter, plugged into a Power Wedge 116.