The Sony MZ-E2 is the first Sony's Portable MD Player, world's fifth. It was designed in early age of MDs; it's premiere in Japan was in December `93 (MD standard was established in `92). The MZ-E35 was designed much later, and put on the market in October `97. That means there are 4 years between them; this is much for an advance in technology.
MZ-E2 uses old ATRAC 2 and E35 uses much newer ATRAC 4; this is the first important difference we can find about them. Improvement of ATRAC can be easily heard. MZ-E2`s sound lacks deep bass and sharp trebles, it gives some metallic-like feeling. Old ATRAC cannot process well MDs recorded in worse quality-like from videocassette or an old audio cassette; it sounds quite metallic and strange. MZ-E35 has none of these problems-sound is very good, spatial, just like a clone of the master source - doesn't matter whether the MD was recorded from a CD or an old cassette. With new ATRAC there is all the bass and all the trebles. Now all the new units have good ATRAC, that's good. But it doesn't mean that sound from MZ-E2 is bad. It is fine; E2 has very good amplifier and it sounds very pure, there is almost no hiss or distortion, bass boost gives great vocals. Sony disimproves the amplifier significantly - why?!? They shouldn't try to be economical at this point. Even though both units have equal 2 x 5mW amplifier power, MZ-E2 has much more volume and it keeps the sound perfectly clear with all the bass even on maximum volume. MZ-E35 lacks volume and few highest volume positions give you only more and more trebles (there is too much of them anyway), distortion appears and you can be forced to turn off the bass boost totally! It is strange, but the old bass boost of E2 appears much better and twice stronger than the new digital one of the E35! Though the newer ATRAC is supposed to give less hiss then the older one, MZ-E35 gives much more hiss! All this causes that classical and vocal parts sound much better on E2 than on E35. I also cannot understand why when Sony invented Groove it didn't appear in it's MD Players - they are more and more lacking deep bass sound with every newer model!
Important thing about digital sound is shock protection. MZ-E2 has 10-seconds memory buffer and E35 has 40-sec. memory, as have most new players. But E2 appears to have better shock protection! It's mechanism is so well-fitting that it handles w even crazy and long shaking, even when starting to play new songs or winding a track, which easily "works" with E35! I find it impossible to make E2 stop playing, so far it worked in every conditions! E35 has not good enough shock protection even for running with in a pocket.... Strange, isn't it? E35 is also much more susceptible to humidity. So Sony disimproves one of the essential things - acceptance of hard conditions! Both units has problems in low temperatures and they consume lots of energy then. E2 looks fragile (made of plastic), but it is not so delicate. E35 is made of metal, so it's OK. Both are easily scratched, and especially E35 looks poor after some time of usage (under silver paint there's gray metal...). I am surprised with it. I hope that Sony will change it; maybe it's only about E35?
Important improvement was made in energy efficiency. E2 plays only about 2,5 hours on it's Lithium-Ion rechargeable battery (3,6V 750mAh), but it depends how high volume you use. Recharge of the battery takes about 5 hours (3 hours for 80%) with auto off function. You can use the unit during recharging - it's done with AC Adapter, which is included with the unit; the Adapter is very useful because the unit's low energy efficiency.. Bad thing is that spare battery costs a lot (about 80$). E2 can also use AA cells - you can connect external case, which takes 3 of them (unit becomes a little bulky). On 3 alkaline AA cells you can listen for about 6 hours (about 10 with both them and the rechargeable battery). This is really not good. E35 uses chewing-gum type NiMH battery (1200mAh 1,2V), which is enough for about 6 hours of playing. You can buy NH-14WM for 25$ and it will be about 7 hours then. Recharging takes about an hour, but battery heats a lot, what is probably not good for it (less charging cycles possible); this is even dangerous. You must have a spare battery to use unit during recharging the battery. AC Adapter is not included, but you can buy it. You can also use an AA cell when external battery case is connected; it gives 8 hours (14,5 both with rechargeable or 15,5 with NH-14WM). This is better, but still not enough. For me of all the Sonys so far (September `99) only MZ-E80 has good enough energy efficiency (16 hours on the rechargeable, 42 both with an AA cell). I hope Sony will keep improving it;)
Comfort of usage. Sony kept improving size and weight. E35 is much smaller and lighter than E2. Next Sony model after E35, MZ-E55 size and weight were just fine, but I don't know why following it models are significantly bigger and heavier (MZ-E70, E80); I hope Sony will return to smaller and lighter players;) Anyway, even E2 with it's size and weight is still acceptable. What is strange, Sony disimproves MD access; E2 has it more than twice faster than E35! E2 reads TOC in 3 seconds, E35 in 7; E2 reaches from the beginning till the end of an MD in 3 seconds, E35 in 8! But so far it is not very important, unless you want to scan beginnings of songs on a fragmented MD... Both units have remotes with LCD, but the E2`s is much more comfortable-keys in good places, much smaller and lighter than E35`s. Good thing is that newer units have backlit on the LCD, which is very comfortable. Both E35 and E2 don't have backlit. But remotes shall be much smaller and lighter; here I cannot see any innovation so far.
Last thing is the design. I think design of the E2 is great even though it's made of plastic. I can hardly accept design of E35. Back side of the unit is very ugly and keys are so small an put so close together that it is difficult to use them. Remote is very bulky and looks unattractive. E35 itself also looks bulky; as I look on E35 it seems to be bigger than E2, even though it is significantly smaller. I cannot understand how E35 could have got a design award! Luckily newer Sonys seem to be more nice to look at, especially MZ-E80 (though I haven't seen it's back side...). It's also nice that now you have choice of colors of units; I myself would buy only black and blue, but others are also not bad. I hope Sony will keep this tradition.
Newer players are getting cheaper and cheaper (E35 was supposed to cost about 350$; E2 even 550$, newer ones go under 300$), which is great unless it's a discount based on worse and worse amplifiers... But I must admit that if E35 and E2 had the same price and I would have to chose between them, I would have a serious problem to decide which one to buy - that means that newer Sony units are not so much better as they are supposed to be; that's not right, I think.
P.S. New Sony MD Player appeared: MZ-E90. Nice size (even slightly smaller than Panasonic SJ-MJ70!), a little more energy efficient (21 hours on rechargeable, 56 hours both with AA cell). Not bad look. I don't know much about it yet, but it seems to have no innovations to comparing previous models...