[stevesolo]

Can someone explain to me why if the battery for the Sony 25S is a 4 volt Nicad, why is the AC adopter/recharger for the unit a 9 volt? Thanks

 

[Audio Redneck]

4v will run the unit from the battery terminals. To run the unit AND charge the battery, dubble that and add a little for the charge circuit.

If you are not charging a battery (ie battery not installed) it will run with as little as 6v, but it still sounds best between 7-9v

 

[OriginalReaper]

Is it normal for a D-25S to get warm?

also, is there any way to add even a lil bit of bass? Just a teensy bit

 

[Audio Redneck]

Warm? A little maybe, but I'll pay attention this weekend.

As far as bass, not without an external amp or replacing the op-amp like some of the guys in the DIY forum are talking about. Don't know if anyone has actually done it yet.

 

[puppyslugg]

Quote:

Originally posted by Audio Redneck ...replacing the op-amp like some of the guys in the DIY forum are talking about. Don't know if anyone has actually done it yet.

mekano plastik has actually done it. He changed the opamp to a ad8620, along with swapping out a few caps. He tells me the bass did improve. At the same time, the highs smoothed out some, too.

 

[00940]

did he keep all the power of the d25s ?

 

[puppyslugg]

Hi 00940,

It is really not appropriate for me to answer questions about the mods mekano plastik made to his d-25. I've emailed mekano plastik, and hopefully he'll be able to answer your question(s).

 

[mekanoplastik]

Hi…

This is what I did..

1-I removed the “X” opamp and replaced it with a ad8620
2-Added some extra caps in the small p.s board in the player.

The d-25 has this “Dual ground sense operational amplifier “ -> http://www.rohm.com/products/databoo...df/ba10358.pdf I found this by chance while trying to salvage a d-25 to repair a d-555… since it is a cheap opamp I thought that maybe it could be replaced. And I did…(without really knowing what the purpose of this opamp is..but I assumed is the analog output)

the player feeds 6v to the opamp (measured using pin 4 and 8).. now the weird part is …the d8620 is not supposed to work with this voltage and the player shouldn’t sound at all…right??..well..it does sound fine.. but now I think that maybe this opamp is not the output one (otherwise it would sound like crap because the low voltage …right??)

After replacing the opamp I noticed a slight lost of volume from the headphone jack (it still has more that necessary..), I also noticed a “increase” (small) of the bass and I don’t know if that makes it to sound a little more relaxed in the highs, but it sounds a little more “round”…not that sharp, I mean….. and maybe it added a little hiss sound (“detail”?? in bad recordings..)

I also added 2 extra 150uf caps in the power supply (now total is 450uf) so maybe that is the reason for the bass change….could be …


Sorry my approach is so un-scientific…I wish I could give more details

i will try to intall the old opamp and compare again....

m.

 

[00940]

thanks for the answer

 

[mekanoplastik]

Well……I think I was mistaken about the function of this opamp…

I looked at the board placed against a very powerful light to see through the board and routed the tracks from the opamp to see where they go… and it seems that only one channel of the opamp is used…!!!!!!! What does this mean??? it means this is not the analog stage I was hoping it to be…. I played a cd without a opamp ,and while it made sound it skipped uncontrollably (the sound, not the track) so it is obvious I was wrong…well..this sucks..

What really puzzled me is the fact that I do hear a small difference (I’m serious) even thou this component is not supposed to affect sound the way I was expecting.. I am very confused (and wearing a full asbestos wear) …and open to any idea or recommendations.

Anyway…I still think it is worth a try (as a matter of fact my player is keeping the 8620) and I will really like to hear from someone else about this same mod…


sincerely
m.

 

[Audio Redneck]

Quote:

Originally posted by OriginalReaper Is it normal for a D-25S to get warm?

O.R.
Sorry I was long getting back on this question. I played mine a bunch in the last week with both my batterypack and adaptor and mine has stayed cool. One question: do you have a Sony battery in the unit(I don't). If something is getting warm, this is the first thing I would think it would be.

 

[LamerDeluxe (tm)]

That's right, a sony batterypack will indeed become warm while being charged. Even when the battery doesn't work anymore