I have owned a Sony MZ-R50 for about a year and use it extensively for keeping me company during long plane flights and rental car jaunts while traveling on business. Although it's a great unit, there are little features about it that I find irksome during extended trips. Many of these small annoyances have been fully rectified with my recent purchase of Sony's excellent play-only MZ-EP11.
The MZ-EP11's best feature is the effortless slot-in loading design- all brands of Minidiscs that I own (Sony, TDK and Maxell) can be easily loaded (or unloaded) with one hand (even the occasional TDK and Maxell disk lots that don't slide freely in the MZ-R50 clamshell) . I have found that it's easy to load disks in the dark while driving with this unit, a feat that I can't easily accomplish with the clamshell design of my MZ-R50. I've had no trouble playing any of the 150ish disks in my collection (all recorded off my MZ-R50 or a friend's Sony 320 deck). The unit is supplied with a stick remote that is virtually identical to the one that comes with the MZ-R50 (but without the semi-useless track-mark button). I find that it's just as easy to use the buttons on the player itself (it has play, stop, << and >> buttons) than to use the remote (it requires twisting action for play and fast forward/rewind functions which are awkward to do with one hand while driving). Since I rarely use any of the optional play features (repeat track, repeat disk and shuffle), I don't use the remote at all. Sony wisely put the power-on light, headphone jack and play buttons on the short side surface of the unit so everything is in sight when the unit is put into my shirt pocket (this is where I keep it while flying). The volume controls are close to the top for easy access in a shirt pocket. This is far more convenient that the button layout on the Sony MZ-R50 which has buttons on the top of the unit and the headphone jack on the side panel so it's awkward to use while sitting in a shirt pocket. Although some of the newer play-only units are smaller and lighter, I don't mind the size and weight- it's still smaller and lighter than the MZ-R50- I don't find either unit objectionably heavy.
I used to worry about damaging the LCD display of the MZ-R50 while cramming it into my briefcase, but the MZ-EP11 player has no such display and I don't miss it (I only really need it while recording). Since the MZ-EP11 has a pilot light next to the play buttons, it's easy to tell if it's on without the display. The case is extremely rugged and I don't worry about crushing it. It also looks great. I've already dropped it several times from desk height with headphones on (accidental tugs)- all three times it didn't miss a beat while playing. It's built very well and is much less fragile than its recorder cousin. One other nice surprise- the player recognises disks recorded in mono from the MZ-R50 so I can tape favorite NPR programs in mono (like Car Talk) and listen to them on the road.
There are several drawbacks to the MZ-EP11, mostly minor carps. I miss having a true line-out jack- I have to plug my cassette adapter into the headphone jack at full volume when I use it in the car. I bought the US version which came with a pair of rather lame folding headphones with the world's shortest cord. Since I don't generally use or take the remote, I've replaced them with a set of Koss Porta-Pro headphones which give slightly louder volume, superb sound and better bass (I don't even have to use the mega-bass feature to get good lows). The US version does not come with a battery or charger; the unit came with just a felt pouch (nice but never used), the remote and a set of headphones. The MZ-EP11's battery compartment can take an optional rechargeable NiCad gumpack (NC-6WM- $12.95 plus $38.95 for the dedicated charger from Sony- ouch!) or a standard AA battery. According to a Sony service rep I spoke to on the phone, there are no other commercial gumpacks that fit this unit, but I don't really believe this. Battery life with an alkaline AA battery: 5 hours (not confirmed by me; just Sony's manual spec.)
On average, I use the player about 10-30 hours/week. Being somewhat ecology minded, I did not want to generate alkaline battery trash, but my luck at maintaining NiCad batteries has never been good- with their stated playing time of only 2 hours on a charge, I'd have to carry at least 8 of these pricey NC-6WM gumpacks for a roundtrip between Boston and San Diego (I do this trip often) or carry extra AA batteries. I solved the problem by switching to 1500mAh AA-sized rechargeable NiMH cells which I purchased off the Mouser Electronics web site (http://www.mouser.com). The stock number is 622-1500AA and they cost $3.60 each (I bought 4 batteries for $17.43 including shipping). Fully charged, they each last about 7.5 hours- just enough for most commercial flights even with a layover. (Your mileage may vary). I store the extras in a penlight for convenience. Many of the other Sony players have similar battery gumpack/AA dual use battery compartments, so these tips may be widely applicable.
I modified my Sony Discman D-465 to charge these batteries to full capacity. This disc player takes Sony's venerable BP-DM20 NiMH battery pack (another expensive $35-ish Sony part). The modification was remarkably easy to do- This BP-DM20 battery has a plastic center which holds 2 individual AA units together- it presses on a small microswitch to activate the charging circuit in the player. This prevents the player from charging standard alkaline AA batteries (which are also accepted by the unit). Since this battery is accepted by a lot of Sony devices, these comments may be of general interest to anyone who wants additional rechargeable NiMH AA battery power without having to buy a lot of expensive BP-DM20 batteries, gumpacks or extra chargers.
To modify the D-465 unit, unscrew the 5 Phillips microscrews on the back and pry the 2 halves of the case apart. CAUTION- YOU DO THIS AT YOUR OWN RISK! Once apart, you'll see the microswitch which activates the charging circuit. On my unit, it's a white part the size of a small sugar cube soldered directly to the underside of the main board. I simply tied it closed with a plastic coated twister-tie from a loaf of bread (trim off the excess). This way, it can be reversed at a later date if I give the player to someone likely to try something stupid like putting in AA alkaline batteries with the power pack connected (caution- explosion or leak hazard). If you attempt to do this, always insert pairs of rechargeable batteries in similar charge condition (full vs partial charge) so you don't accidentally overcharge one of the batteries. To charge the batteries, press play, then stop. At that point, the charge symbol on the LCD should start pulsing. If the batteries don't start charging (this can happen if there was already a set of charged batteries in the unit prior to use), unplug the power cord from the unit, press play, then plug the power back in. Press play, then stop and charging should start up again. I use the device when I've accumulated 2 batteries that no longer work in the MZ-EP11 due to discharge. I've not tried to do this mod with other Sony BP-DM20 compatible devices, so you're on your own.
Subsequent to my own mods, I discovered several web sites that sell AA NiMH batteries and chargers inexpensively (see http://nimhbattery.com/gp-130aah-aa-nimh-batteries.htm and http://www.steves-digicams.com/nimh_batteries.html) along with a nice FAQ on NiMH batteries (http://nimhbattery.com/nimhbattery-faq.htm). I've not purchased products from any of these suppliers.
Like the MZ-R50, the MZ-EP11 is not the most current iteration of player in the Sony line, but it's a great, basic sturdy unit with good looks and great sound and the price was right for me. I purchased mine on sale at Crutchfield for $179 ($186 with overnight delivery). They included 3 blank MD's, a pair of fresh alkaline batteries and a coupon for a free cassette adapter and a cigarette lighter plug (I haven't received these yet). I've noticed that many stores still carry the unit (saw some at Best Buy in Cambridge, MA a few weeks ago and spotted quite a few this week in New Orleans at many of the electronics shops down on Canal Street).