[zorin]

 
Man, I didnt know about the internals and got rid of D-35 and kept the D-25. I use MDR-V6 (easy to drive and comfortable for me to listen for a period of time) When I listened to both (Mega-Bass off
on the D-35), the D-25 sounded more neutral and the D-35 sounded bright.
 
The D-35 had far more functions than D-25.
 
I'm always looking out for a D-25 battery pack and havent seen one in ages. It looks something like the regular battery pack that attaches at the bottom but has a slot in the middle that holds 6 or 8 alkaline batteries. Are you familiar with what model no. it is?

D-25 / D-25S / D-250 has the best sounding, clean and clear treble of all the Sony discmans. I could even use the word 'unbelievable' when referring to it.
D-35 / D-350 has a rough sounding patch of its treble, somewhere between, to my ear, 6000 Hz and 10000 Hz, and it causes treble to sound 'over the top' a bit. It is not shrill bad but one can hear it. I think the blame could be assigned to the D-35's digital filter. The problem is that when listening to badly mastered albums / tracks that have shrill high frequencies, D-35, because of its treble, makes things worse. In these cases it would be better to use some other model of Sony discman, or to use headphones that have rolled off treble.
I am currently trying to find actual rechargeable batteries for some Sony discmans; it would be worthwhile because they comfortably beat, in sound, the current line up of digital portable music sources. Almost a quarter of a century old small electro-mechanical machines sound better than the modern digital marvels. 
As for a battery pack, there might be a better solution, I sent an email to a battery manufacturer and if things turn out right I will let you know.

 

[warubozu]

   
But my D-35s are not dead, they are alive and well and well treated and happy.

What I meant is some people feel the need to resurrect a dead thread some two years after my last reply in 2008. That's great that you have a well kept and fully functioning D-35, as I now also have a excellent condition and fully functioning D-35 which I got back in 2009. Wasn't going to buy but it as I already have enough vintage PCDPs but was able to negotiate a good price with the seller. I would agree with you that the D-25 has a very smooth and clean treble, not sibilant, making the D-25 more tolerable in listening with bright cans than other vintage Sony PCDPs.

 

[AUDIOBREEDER]

  D-25 / D-25S / D-250 have the best sounding, clean and clear treble of all the Sony discmans. I could even use the word 'unbelievable' when referring to it.
D-35 / D-350 has a rough sounding patch of the treble, somewhere between, to my ear, 6000 Hz and 10000 Hz, and it causes the treble to sound 'over the top' a bit. It is not shrill bad but one can hear it. I think the blame could be assigned to the D-35's digital filter. The problem is that when listening to badly mastered albums / tracks that have shrill high frequencies, D-35, because of its treble, makes things worse. In these cases it would be better to use some other model of Sony discman, or to use headphones that have rolled off treble.
I am currently trying to find actual rechargeable batteries for some Sony discmans; it would be worthwhile because they comfortably beat, in sound, the current line up of digital portable music sources. Almost a quarter of a century old small electro-mechanical machines sound better than the modern digital marvels. 
As for a battery pack, there might be a better solution, I sent an email to a battery manufacturer and if things turn out right I will let you know.

Hey Zorin, do let me know if you find some sort of battery pack. I have 3 wires popping out from 3 sides of the player (power, remote & headphones). My battery is long gone dead but I saw on you tube a guy mentioning he resurrected the battery by opening it and putting new lithium ion batteries.
I went back to CD listening as there is a thrift store close to my home selling used CD for .99 cents in mint condition. As you said these discmans sound much better than anything out there and I'm not going to spend $500 plus on digital music listening when I know CD provide the ultimate listening experience.

 

[faichiu]

Still love the sound of my D35, D303, D321.  Best sounding ever!

 

[zorin]

  Still love the sound of my D35, D303, D321.  Best sounding ever!

D321 better than D311 ?

 

[faichiu]

I don't have D311 to compare.
 
But this thread is a great resource for Discman review.
 
http://www.head-fi.org/t/31233/personal-cd-players-through-the-ages-a-review-updated-10-05-2003
 
Quote:

  D321 better than D311 ?

 

[schalliol]

Does anyone still have the plug in IR sensor for the guys or maybe a spare?
 
I remember buying my D-35 as a kid from the Service Merchandise catalog, waiting and waiting until I could get it.  The music calendar and A-B options were truly akin to an ES product.