I just picked up the Panasonic SL-CT820. This is just about the smallest portable CD player you can get (to invoke a popular tech writing cliché, it's a "marvel of miniaturization"). Its vintage is December 2004.
I can't compare the Panasonic SL-CT820 to the Sony D-NE20, but I have the Sony D-EJ2000 (owned since 2004). The Panasonic has what they call a D.Sound digital amplifier – the Sony D-EJ2000 has an analog amp. I've read that the Sony D-NE20's digital amp doesn't sound very good, but the Panasonic drives both my Klipsch S4i and Alessandro MS-1 headphones to loud volumes without any audible problems – it has several equalizer modes, which I've turned off. So far, the Panasonic sounds very close to the Sony, edging it slightly with more extended treble and bass and a slightly more dynamic sound – most likely due to having more power to drive the headphones. They do each have a distinctive sound signature (though both are overall clean and neutral-sounding) – I'll post an update when I've listened to more music on the Panasonic. Most listeners wouldn't be able to tell they were listening to a digital amplifier, which is a good thing.
The Panasonic comes from the awkward era of MP3/WMA-playing CD players, and it also plays CD-R/CD-RW discs (this was a big deal at the time) as well as discs burned in the defunct HighMAT format. The Sony, on the other hand, only plays Redbook CDs, while its sibling flagship players, the D-NE10 and D-NE20, dabbled in MP3 files (and probably ATRAC3). This was truly the sunset period for portable compact disc players, though it took several years for them to completely vanish from store shelves. These were the last flagship players (iRiver also had the well-regarded SlimX iMP-550), desperately trying to navigate folders of newfangled MP3s on barely-legible LCD controllers as the iPod (released in late 2001) was becoming the predominant portable music player. Sony and the other manufacturers only produced budget CD players after hitting this high-water mark.
One critical difference between the Sony and the Panasonic is their power supply. Both players are only slightly larger than a CD disc, but the Panasonic is heavier, using 2 gumstick batteries where the Sony uses 1 and the Panasonic is built from what feels like aluminum, while the Sony's body is composed of an exotic magnesium alloy. The Panasonic manual claims an
incredible 45-hour battery life playing regular CDs, where the Sony gets about 10 hours. Also, the Sony doesn't charge gumstick batteries very well (internal resistance may be an issue), but the Panasonic seems to charge them properly. Both players also come with external battery packs: the Sony uses a single AA battery while the Panasonic uses 2 AA batteries for a claimed total 120-hour play time (internal + external batteries) – it's almost as if Panasonic was determined to double everything in the Sony.
The SL-CT820 uses 2 gumstick (prismatic) batteries – mine came with two Sony NH-14WM batteries. I'm currently trying the Vapex 1450 mAh gumstick batteries that I bought on eBay and they are working well. This player came with a UK power supply, but I found an AC adaptor (RFEA405C) from another Panasonic player (the SL-S160) with equivalent power and jack and it seems to charge the player properly. Get the proper AC adaptor (RFEA415C-1S) for the SL-CT820 in North America if you can, though.
Both players are attractive, although the Sony's magnesium-bodied dark charcoal design is a bit more distinctive – Panasonic sticks with their tried-and-true powder-coated silver look (strongly related to preceding, popular SL-CT800 and SL-CT810 players). In practice, both players are very similar in size and weight. You probably wouldn't take them on the go any more – we have better players (i.e., your phone or DAP) for portable use. The Sony has a charging cradle which the Panasonic lacks, but either player can plug directly into their AC adaptor. Both players feature bass boost and presumably some kind of buffer and mechanical anti-skip mechanisms. More interestingly, the Panasonic features 2 "3D" modes (DSP which seems to add echo) as well as a "Digital Re-master" mode for MP3 and WMA files.
Veterans of the CD era may argue that older vintage players sound better due to their beefier amplifiers or superior mechanical/build qualities, but these sunset players achieved the pinnacle of light weight, slimness, media flexibility, and long battery life. The battle against lossy files would be lost, but not before these high quality, high-tech players were released to a mostly-indifferent public.
