I give the MDS-JE510 a mixed review.
When I listen critically to LP and CD copies through my Magneplanars, I notice a reduced soundstage and a definite softening of frequencies above 10,000 hertz. Sometimes I detect the absence of the transient "snap" from my Shure V-15 cartridge and CD player. Using an equalizer, I have had to boost the upper range by 2-3 db. in order to closely match the original. I'm awaiting later versions of ATRAC to remedy these deficiences.

On the other hand, the editing and features are superior to cassette. No longer is it required to adjust the bias. Background noise is absent. No more dropouts and worn tapes. No more wow/flutter.

I sincerely hope the Minidisc format is here to stay and that we soon have a wider selection of higher-end decks.

From what I've read on this page I see almost everyone likes this one. As for me I have two doubts about this deck. First is the loading mechanism. I'm not sure whether my problem with it is common to all issues of 510.To the point: my machine (USA import, lacks coaxial input) after about half year of good performance picked up a strange habit of coming alive in the middle of the night with the disc ejected but not physically removed from the slot. I presume that the sensor thinks the disc is being reinserted and the deck turns itself on. However I don't understand why this can happen after many hours of being switched off with the disc untouched, for Poland (that's where I happen to live) is as far as I know a non-seismic region. I've heard rumors that this is not a fault present only in my very machine, and that some cases of this gizmo have been reported here and there. Things got worse after a while, and now the deck sometimes comes on without a disc in sight. The only "stable" condition is with the disc loaded in the machine and switched off (it never came on in such position, but who knows what it's up to next ?)
The second doubt is the Toslink connection. It's true that the sound quality exceeds any tape deck I've heard (I own a SONY TCK-611S and it was buried alive by the 510). Still copies made through the optical input sound shallow compared to originals. I'm not sure how much of this difference comes from the CD player I use (Pioneer PDS-904). When used as a transport I presume that the 904's Legato-Link circuit is bypassed and only the factual (not effected by Legato-Link guessing-game) bits on the CD are transferred to 510. This may be the main source of the audible difference (more a loss actually) in sound quality between the two. Still I have heard that Toslink (I use a Monster digital interlink cable) connection may sound inferior to coaxial. This is in fact quite hard to explain logically for digital bits are digital bits and I can't imagine a "one" being sent and "zero" being received instead. Such a possibility would suggest that the effects of jitter had been to be completely overlooked by the inventors of this connection at it's very beginning.
Besides these doubts I still find the 510 a very good performer and unless it starts coming on at night and killing people I'll probably stick to this opinion. My rating: 4.5 with good loading mech, 4 with the one I have and a coaxial digital input (which mine lacks), 3.5 my very model. This gives 4 as a somewhat abstract average.

I got an MDS-JE520 for Christmas and am I impressed! As a long time audiophile (34 years)I was a sceptic at first. I tested with ADK 240 headphones, which reveal flaws better than any speaker at any price, and was amazed. Direct digital recordings of CD's and recording of vinyl records are indestinguishable from the original. This $250 deck beats any cassette recorder at any price! It is much easier to use than a cassette deck and much more convenient. I highly recommend this product to anyone interested in recording.

I actually use the MDS-JE500, which is really not that different.I like the flexibility of the MD-system, and the sound's pretty decent,

but...
My deck also has the annoying "turn on without a reason" bug. My dad's 500 has the same problem. I wonder if Sony know about this. They probably do, but they wont admit it. This doesn't seem to be a big problem however.
I recommend it.

I can't remember the model # of my bottom of the line Sony MD deck, a JE320?, but I'm quite happy with it. Much better than cassette. However, the instruction booklet could be better and a coaxial input would have been better than optical. The instructions don't mention remote control, but a Sony universal remote with a md setting actually works just fine. I have no complaints about the sound at all, though I can only record through the analog jacks, my Rotel CD having only coaxial out. Nice machine for $200.00. Work on that instruction manual, sony.

The 510 is a good solid sounding unit that show the MD medium in a good light. Give MD a try and you'll like it.

Yeah, it's good to know that there are others out there with this unit that has the same "I'll turn on whenever I want to" problem. I first thought that the garage door opener or some signal source was interfering with the thing, oh well. I just use it for making mixes for working out and trips. It's a pretty decent entry-level MD deck.
Take away one star for the phantom turn-on bug. Just hope it doesn't decide to die on me one of these days.

I bought the 510 bundle at Sears and am impressed with the sound quality and ease of use of the home unit as well as the quality of the portable. I made the mistake of not getting the extended warranty though. The auto on feature was disturbing but not as bad as the disk won't come out problem. I leave the cage off now so I can retieve my disk from time to time. I think next time I will spend the extra money and enter the ES line--5 year warranty too.

I bought the JE510 minidisc recorder in June 1997, the month it arrived in stores. Fot the first 18 months, it worked wonderfully -- I was amazed at the editing capabilities, and had loads of fun making mixes and combining tracks, etc. And the sound quality was great. I had no complaints. Then, about 6 months ago, I started getting a "DISC PROTECTED" error when I would try to record on a disc whose record tab was not in the protected position. It was an intermittent problem that got worse and worse, and then one day the motor just stopped working and it wouldn't even accept a disc to play. I know for a fact that tons of people have had problems with this model. A machine like this shouldn't break in under 2 years!!!! I am now shopping for a new model, definitely non-Sony, either a Kenwood or a JVC. Sony's lost a customer for life. I'd give it 5 stars for when the unit worked, but it doesn't!!! Argh!!!

Had my JE-510 since early '98. Almost in constant use, sound quality is great - this machine was voted in the UK highly for this. Can't complain - never had any disc 'loading' errors though so I've got to give it the full monty of stars... Mind you in late '97 my top of the range Sony video developed a loading fault which I identified as me only pushing the tapes in too slowly...wanted to protect my investment at the time! Since then when I load videos or minidiscs they get a good firm push right into the loading slot, maybe this explains my having no problems so far! Though if it does play up in the future these minidisc players are cheap enough to replace so I'm not too bothered. Keep minidiscing guys!