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Review: Sony D-25S Portable CD Player (LONG)  

post #1 of 105
Sony D-25S Discman
With brief comparisons to the Panasonic SL-CT570
All text and photography Copyright (c) 2001, by Russell A. Arcuri.


The Sony D-25 was Sony's flagship portable CD player from 1989 - 1992. At that time, it cost about $320. My roommate in college had one; I got by with a Sony D-9, a much lower-cost model. Unlike many portables from that era, and unlike ALL portables made today, the D-25 was made mostly of metal. It came with a wired remote control and a cloth carrying sleeve.

So what, then, is the D-25S? These are being sold on eBay as new "old stock" by a company called "Silicon Salvage." Apparently, these have been in storage for a long time, until Silicon Salvage picked them up and started auctioning them off.

I had a brief conversation with a couple of people from Silicon Salvage. One of them explained that the D-25S was not sold as a consumer product in the U.S. Rather, they were supplied to airlines for use by their passengers (one would assume in first class). Externally, the D-25S appears to be identical to the D-25, except that while the D-25 was black, the D-25S is a light metallic color best described as a brassy grey.

For this review, I will assume that the D-25 and D-25S are identical internally. They accept all the same accessories, and appear to function identically. It is possible the headphone jacks have differing amounts of gain, but I will address that question later in the review.

How do I get one?

This is a bit of an adventure. To get a D-25 or D-25S, you'll have to hunt the used market. An eBay search is probably a good start. The D-25 model is occasionally seen there, with most or all of the accessories it originally came with. The D-25S is a different story. You can look for one of the Silicon Salvage auctions, with a "Buy It Now" price of $45 plus shipping. Be forewarned that these come with NO accessories. No rechargeable battery, no AC adapter, no remote control, no protective sleeve. Just the player.

The critical accessories for the D-25 are available from Sony's parts ordering, though you'll pay an arm and a leg for everything. They get $46 for the AC adapter, $31 for the BP-2EX rechargeable battery, and $5 for the manual. Radio Shack sells a 9V, 800mA AC adapter for $13.99 which works fine with the D-25S. Get adapta-plug "M." Unfortunately there is no third-party alternative for the proprietary 4V, 600 mAh battery pack. After shipping, you'll pay $40 for the battery alone. And there's no option to use standard batteries like AA or 9V alkalines.

So is all this work worth it? I'd answer that question with a qualified "yes." I'll explain further in the following sections.

Physical description and build quality

It's built like a tank. I'm fairly confident it could be used to smash most modern CD players into tiny pieces and still play okay afterwards. As previously mentioned, it's made almost entirely of metal. Fairly hefty to begin with, but incongruously heavy with the battery pack inserted. More than one person has picked it up and said, "Wow, pretty heavy." Good or bad? You decide. It's certainly not going to fall apart through normal use & minor abuse.

It's slightly shorter than a jewel case in length, the same width, and about as tall as two jewel cases stacked. The 'hump' in the middle/left side of the cover is slightly taller, and incorporates a window which allows you to see your discs spinning.

Aesthetically, it is one of the nicest-looking portables I've seen. It's all just a matter of taste, of course, but I like its clean lines and solid appearance.


Let's see. It plays CDs. That's one. And it, um... well, I guess that's about it. It doesn't have a coffee grinder attachment (though I suppose you could put the beans inside the edge of the cover and pound on the lid). Seriously though, it doesn't have any of the features that 21st century consumers demand. To wit:
  • It has no anti-skip mode. Bad if you want to walk around with it or set it on the seat of your SUV when you go off-roading. Good if you care mostly about sound quality.
  • It has no equalization whatsoever -- not even a "mega bass" switch. Bad if you're using anemic cans. Good if you care mostly about sound quality.
  • It lasts about three and a half to four hours on a full charge. Less if you're driving power-hungry headphones or are trying to see how quickly you can make yourself permanently deaf by cranking the volume. Bad if... well, I guess it's bad if you want it to last longer than three or four hours away from the AC adapter. But the alternative is what we have nowadays -- compressed antishock modes and anemic headphone amps.
  • It has no "resume" feature. Bad if you like the resume feature. Good if you hate the resume feature so much that you don't even want it as an option.
I would be remiss if I didn't mention a few features it does have that most modern portables don't have.
  • It has a line out. A few short years ago, most portables had this feature. Increasingly rare as each year passes.
  • It has a backlit display. Backlighting is active when the unit is plugged into the AC adapter. Again, reasonably common a few years ago. Nearly extinct now, in the never-ending quest for longer battery life and cheaper component costs.
  • It has "Index." If you're younger than around 30, you're probably wondering what that is. The redbook CD specification allows for two kinds of markers. One is "track" -- you hit the FF or RW button and it jumps to the next or previous tracks. No problemo. "Index" allows CDs to be mastered with 'jump to' points within each track. So a long track, like "2112" on the original CD pressing of Rush's "2112" (1976, Mercury), can be broken up into smaller chunks. The D-25 and D-25S allow you to actually use this feature on those rare discs which support it. Just try to find a modern portable player that supports this. Heck, it's pretty rare to find even on a full-size rack-style player now.
  • It has "time remaining." You can press a button which switches, round-robin style, between elapsed track time, time remaining within the current track, and time remaining until the end of the disc. For reasons beyond my comprehension, this useful (IMO) feature is missing on many modern portables.
It probably has most of the other features you're looking for in a portable player, though the interface is a bit unusual if you're used to how newer players work. We'll cover that in the next section.

Operation and Interface

Okay, you've got the player and you're ready to use it. You open the cover, and attempt to press the CD down onto the spring-loaded ball-bearing hub. Whoops- it has no spring-loaded ball-bearing hub. Instead, you set it down on the hub, which doesn't grip the disc in any way. When you close the cover, a round, freely-rotating plate in the cover closes over the center of the disc, providing the stability and friction the motor needs to get the disc spinning.

You press the play button, and decide to skip ahead to track 3. No problem... pressing the >> button twice does as you expect it to. Now you decide to fast forward within track 3 to that rippin' guitar solo you've been wanting to hear. So you press the >> button, holding it down to get the player into "fast forward" mode. Nope. You find that you're rapidly skipping ahead one track at a time, as if you pressed the >> button repeatedly. That's because you have to press the "key" button once to get the player out of "track skip" mode (Sony calls it "AMS") and into "fast forward/rewind" mode, which Sony calls "SEARCH." Note of warning -- fast forwarding while the player is in "pause" mode is MUCH quicker than fast forwarding when the player is in "play" mode.

Okay, that minor issue worked out, you listen to the guitar solo, and decide you want to skip ahead to another track. So you press the "key" button, then press the >> button. Whoops again -- you're not back in "track skip" mode yet -- you're in "index" mode now. Since your CD probably doesn't have any indexing information, the player will rapidly scan through the rest of the track looking for an index mark, and when it fails to find one, revert back to the beginning of track 3. So keep in mind that the << and >> buttons are capable of doing three different things depending on how many times you've pressed the "key" button.

Yes, it takes some getting used to -- but it functions fine once you've got it worked out.

Sound Quality

Well, I've spent an awful lot of words without mentioning the one thing Head-Fiers are probably most interested in. How's it sound? In a word, outstanding. I have no specifications available to me at the time of this writing, so I can't tell you how many mW the headphone jack delivers, or the type of DAC employed. I only know it's not a 1-bit DAC, since the first single bit DACs didn't hit the market until after the D-25 was first put to market. I consider this a good thing, since the majority (though not all) 1-bit DAC implementations left audiophiles underwhelmed.

The line out: Superb. Very clean, very detailed. This is probably the best line out of any portable player I've tried, and I've tried a bunch. Compared with the Panasonic SL-CT570, it seems like there's more detail and greater realism in the treble range. Cymbal taps are gorgeous with the D-25S -- they're real and palpable. Cymbal crashes are more real as well. Bass is tight, extended, and strong. The only caveat is that the line-out provides a less powerful signal than a typical home CD player, so if you tie it into a receiver or pre-amp for use in a home system, you need more gain on the volume control to get it to reasonable volumes. Of course, this is true of most portables, including the Panasonic 570. With a dedicated portable headphone amp, there should be no issues.

The headphone jack: I think I've finally found the answer to the question, "Can a portable player drive Sennheiser HD580s?" The answer is "Yes, if you're using a D-25S." The D-25S easily drives my HD580s to extremely loud levels without distorting -- an astonishing feat if you're used to the poor quality of most headphone jacks on portables. The Panasonic 570 is touted as being fairly powerful, but is incapable of driving the HD580s loudly without distorting some. Bass response also suffers in the HD580s when driven by the Panasonic 570's headphone jack, even at normal not-terribly-loud listening levels. The D-25 drives them much more loudly than the 570, and cleaner to boot. The bass response is also surprisingly good -- tight, strong, and not at all muddy, though it begins to tail off at volumes higher than I care to listen at. I have no qualms about driving my HD580s with the headphone jack of the D-25S, and have done so many times, with a big stupid smile on my face. They really do make music together.

Yes, Russ, that's all very impressive. But how does the headphone jack sound when compared to a dedicated headphone amp?

Read your mind, didn't I? I've compared the headphone jack of the D-25S to my Altoids amp (CHA 47 built with a gain of 5 by JMT) and to the headphone jack of my 1993 Onkyo Integra DX-C606 CD changer.

A quick word about the Integra 606, for those who might have missed the dozen or so times I've talked about it previously. It has, quite simply, the best headphone jack of any device I have ever tried that isn't a dedicated headphone amplifier. Sadly, I have been unable to find any specs for it. The Integra line was to Onkyo in the early 1990s what the "ES" line is to Sony. The headphone jack is gold-plated and the volume control is very smooth. It drives my Sennheiser HD580s to ridiculously loud levels cleanly and beautifully. That player also has one of the few single-bit DACs I care to listen to -- better and more musical, in my opinion, than even the newest 24/96 DACs used in almost everything nowadays.

Anyhow, back to the D-25S. In a direct comparison with the CHA 47 Altoids amp, it fairs pretty well. The CHA 47 will play slightly louder. Yes, I said, "slightly." The D-25S has ridiculous amounts of gain compared with the Panasonic 570 or any other portable player you can buy nowadays. It can, I'm certain, cause permanent hearing damage within short order if you crank the volume control. This seems odd to me, primarily because it's a portable player. It's also the only reason I have to think that there might be some difference between the D-25 and D-25S. If the D-25S truly was intended only to be used on airplanes, it would make a certain amount of sense for it to have more gain than the D-25, to help overcome engine noise. I don't currently have a D-25 available to me to make a comparison with, but I should have one within a week. I guess the mystery will be settled then and I will update this review with the new info.

At normal listening levels, the quality of sound delivered by the headphone jack is surprising enough to put a smile on my face when I think about it. I'll be listening to a well-recorded CD like "Happy Anniversary, Charlie Brown!" (1989, GRP Records) and hear how beautiful a bass run, saxophone solo, piano tone, or cymbal tap sounds. Then it will occur to me that I'm actually driving my HD580s directly out of the headphone jack and I can't help but smile.

Pushed to louder levels, the CHA 47 distinguishes itself by delivering tighter, stronger bass -- especially around 100 Hz. "Wait," you're thinking, "isn't 100 Hz where the impedance curve of the HD580s reaches its peak?" (Well, you might be thinking that if you're a geek too.)

"Yes," I answer, "that is precisely where the peak is on the HD580's impedance curve." In simplified terms, what this means is that with the HD580s, a given headphone amplifier must be able to deliver more power to make 100 Hz sounds than it does to make (for example) 400 Hz sounds. What my informal tests show is that the D-25S can deliver enough power to play nearly as loudly as my CHA 47, but that it reaches a point below top volume where it's no longer able to provide enough power to make 100 Hz (and surrounding) sounds as loudly as the rest. Still, that's not a bad result when you consider that this behavior disappears at normal listening levels, where the headphone jack is capable of delivering enough power to make the bass sound right.

The D-25S also suffers a bit when compared to my Integra 606's headphone jack. I suspect that's due to the fact that I absolutely LOVE the sound of the 606's DAC. Nevertheless, the 606 delivers more power and volume than even the CHA 47, so I don't think the D-25 fares too badly there either.

The practical upshot of all this exposition is this: I can, when I don't feel like taking the time to find and set up a dedicated headphone amplifier or sit in my living room near the 606, simply plug my HD580s into the headphone jack of the D-25S, and get beautiful music out of them. This is a really wonderful thing to me. I have a decent selection of other headphones to choose from, which are much easier to drive (including Grado SR-80s, Sony MDR-V6s, and Koss KSC-35s). But in my heart I'm a certified member of team Sennheiser, and it does my heart good to know the D-25S can drive them as well as it does.

Caveats & Wrap-up

Yeah, I'm kind of long-winded. I promise, though, we're almost done. We're left with the following question: Why would anyone choose a D-25S over a modern portable like the Panasonic 570?

Logic tells me that it makes little sense to buy a 9 year old portable player, even if it was never used. (A sticker on mine indicates it was assembled in July, 1992.) The stepper motor sounds a little loud when it moves the lens back to center after it's done playing a disc -- a sure indication that the lubrication on the worm gear has either evaporated or dried up and fallen off during its 9-year storage. I spoke with an electronics repair person who quoted me a price of $10-$20 to disassemble it, lubricate the worm gear, and re-assemble it. I suspect any player in storage for 9 years would need similar attention, though I only have one D-25S at present. Maybe they aren't all like that.

So obtaining, outfitting, and maintaining the D-25S is a hassle, and not inexpensive either. We're talking $50 for the player (including shipping), $40 for the battery (including tax & shipping), $15 for the Radio Shack AC adapter (including tax), and $10-$20 in labor costs to quiet a noisy stepper motor. That comes out to about $125, and lacks headphones, the remote control, the cloth carrying sleeve, and a manual. My Panasonic SL-CT570 cost about $90, and includes all the standard accessories. I believe the cost of the 570 has come down another $10 recently as well.

I look at it this way: You've got to define your "needs," "wants," and "doesn't matters." "Needs" are those pros or cons which are showstoppers. If your portable player MUST live attached to your belt while you're walking around, then "antishock" is one of your "needs," and you don't have to think any further. The D-25S is not for you.

Conversely, if one of your "needs" is "able to drive Sennheiser HD580s cleanly without a dedicated headphone amp," then the D-25S might possibly be your only choice.

Considering your "wants" is actually a lot more fun. You probably don't need your portable player to be made of metal or look as sharp as the D-25S does. But you might very well want it to. You don't need to have a portable player that nobody else on your block has ever seen, but you might want to show it off. (Trust me, even people who have owned a D-25 give the D-25S admiring looks. It's different than theirs.)

The "doesn't matters" are pretty obvious, I think. If you NEVER use mega-bass, for example, then it doesn't matter whether your portable player offers it or not.

In the end, I am VERY happy with my D-25S. I'm getting the stepper motor lubed soon. It's going to live on my desk at work, plugged into the AC adapter 90% of the time, providing tunes for whatever headphones I want to use -- even the HD580s. Hopefully this review will help others decide whether the D-25S is a worthy addition to their pile of equipment.

Questions and comments are always welcome. Thanks for taking the (considerable) time it must have taken to read this far.

Sunday, 9 December 2001.

Addendum -- Monday, 10 December 2001

Just to give an idea of the amount of gain the D-25S delivers, here's a specific example intended to eliminate differences in the volumes of various CDs. The volume control on the D-25S looks like this: MAX 8 6 4 2 MIN; see the above photos to get the idea.

I'm listening to "Walk On" by U2, track 4 from "All That You Can't Leave Behind" (Interscope, 2000). The volume is set between MIN and 2; the 2 is directly beneath the "O" in "VOLUME," and the "M" in "MIN" is directly beneath the "M" in "VOLUME." I consider this setting to be "1." The HD580s are at a pleasant volume in a quiet room, and sound quality is excellent.

Now I'm cranking the volume up to the point where I would have listened in my teenage years (aka too damned loud) with my eyes closed. Taking a peek, I'm now at volume level "3," which means the 4 is directly below the "O" in "VOLUME," and the 2 is directly below the "M." I'm fairly certain that turning it up any higher would be detrimental to my hearing, if it's not already. Sound quality has been fully maintained, with bass tight and strong, midrange and treble wonderful to behold. That's at 3 out of 10, with Sennheiser HD580s.

Now pulling the Senns away from my ears (for safety), I turn up the volume more. I realize that this is unscientific at best, but as near as I can determine, the treble and midrange don't start to outstrip the volume of the midbass region until I hit about 8. There's absolutely no question in my mind that even listening at 5 or 6 is dangerous, and I believe sound quality is being fully maintained at those levels.

I mentioned the CD and track I used so that a reasonable comparison can be made by others with their equipment. CDs are mastered at wildly varying volumes, so it's important to use the same one I did. I picked it because it's relatively popular (more people are likely to have it), and relatively recent (unlikely there are different master pressings which could be at varying volume levels).

2nd Addendum -- Monday, 17 December 2001

Well, I got the D-25 finally. I can now report that the D-25 seems to have the same headphone amplification as the D-25S. It too has lots of gain and enough power to drive the Sennheiser HD580s well.

You might wonder if there are any differences between them other than color. The only one I've found is this: the stepper motor in the D-25 is MUCH quieter than the stepper motor in the D-25S. I've now had the chance to play with two different D-25S models, and both had motors which were significantly louder than the D-25. This might have something to do with the S models being stored unused for so long, or they might actually use different stepper motors. The D-25 I have now has a "manufactured" sticker saying it was made in February, 1989, making it more than 3 years OLDER than either D-25S I've played with. So maybe they do have different motors.

Anyway, what really matters here is the sound, and as I mentioned above, they appear to be identical in that respect.
post #2 of 105
Awesome review... this one definately needs to be permanently archived. That is also the best looking CD Player I have ever seen. I think I'm going to check around for it right now.
post #3 of 105
Very nice review! and cool pics too..
post #4 of 105
WOW. No time to read this now, but I'm looking forwards to it(gotta study for a french test )

Compared to the ct570 I told my sister she wants for x-mas.
post #5 of 105
Great review Russ!

I take it you got the manual from Sony?--does it mention specs in the back, like the power output on the headphone out?

I got the battery and (stupidly) bought the AC adapter from Sony (I was on the website and thought, "Hell, why not."). I agree with you that the gain on this unit is just crazy. On super low impedance phones like my e888 earbuds, my normal listening level is with the pot at "min." That's right, turning it to the absolute lowest level, sound still leaks out, and it's enough for normal listening! I did listen to it w/ my Senn 580s, and you're right, it is pretty damn good for a portable!

I've also found that even without anti-shock, the unit does not skip very easily. It would probably be fine as a portable unit in a cushioned bag.

Still, I'm thinking of selling mine soon. It's a good stationary home unit, but I still prefer the 777 as a portable.
post #6 of 105
yes, did you compare it to the d-777? i LOVE the form factor of that older player. i remember seeing one at a party in the early 90s and thinking how amazingly cool it looked. glad to hear it sounds good too. i really dislike the modern trend of flash (lots of stickers and shiny buttons on cheap flimsy plastic parts) over substance (metal parts, clean lines, and of course LEDs instead of LCDs ) in today's pcdps. my rz70pc md recorder treads that fine line between the two, with a clean square construction of all aluminum, but with shiny silver buttons.

"the shiny CANDY-like button!" sorry. couldn't resist.
post #7 of 105
If I remember write, no candy is made of metal...

*Looks at *brother's* NW-MS7, studded with Hello Kitty stickers... CUSTOM-MODDED WITH CARTOON BUTTONS...*

Now *that's* what I call 'candy' one of these days he won't be able to find the player 'coz I ate it
post #8 of 105
Looks very similar to my D99 (circa 1990). The D99 can drive my HD600's adequately at normal listening levels - but i intend to get a portable amp anyway and make use of the lineout. The manual states the headphone jack provides 9mW / channel.
post #9 of 105
The manual for the D-25 list the output level of the headphone jack at 9 mW/channel as well. Oh, and bravo, Russ, on the fine review!
post #10 of 105
9mW for senn hd580s?
post #11 of 105
i was thinking of that old ren & stimpy cartoon where stimpy is being tempted to press the history eraser button...

i'd like to add that discman to my collection of rare sony portables, that and the model that plays the 3" cds. i always thought that was cool as well. maybe i should write a sony fetish web page...
post #12 of 105
Remember that the manual states 9mW for the D-25, which may not be the same as the D-25S. The latter definitely drives the 580s fine, which makes me think it's more than 9mW. My old D-777 was 10mW, and it had some trouble.
post #13 of 105
That's very true, Kubernetes.
post #14 of 105
Very interesting........right now, I'm fairly happy with my Sony DE-220, which is low-level model with no line-out. Sounds good to me, though..............D25S.........cheap...........a ah......
post #15 of 105
Well Russ, all I have to say is

Gimme that, gimme that, Gimme, gimme, gimme that!

Gimme that thing, Gimme that, gimme gimme that!

Gimme that thing, Gimme that, gimme gimme that!

Gimme, gimme gimme that thing!

Just placed a bid on a broken D-250 on eBay, even if it should turn out to be unrepairable I can still use the batteries for my Denon DCP-100
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