Conference cookie::notes$archive:cd_v1

    re .0:
    
    > I am using a pair of Sony MDR-022 headphones which do not have great
    > range (20-20,000 Hz) but will do for the moment.
    
    What is wrong with the 20-20khz frequency reponse from your headphones?
    
    - M

    I got one of these in July, and have been very happy with it.
    
    It's on sale at Lechmere this week for $179.98.
    
    Ken....
    

    The frequency range of your headphones exceeds the range of human
    hearing.  The TONE is more of a factor to consider when selecting
    headphones.  I bought some pricey Technics phones with a very wide range,
    but they did not sound good.  I exchanged them for AKG's with a
    smaller dynamic range but much better sound quality.
                                     
    Shawn

    
    I got one of these for Father's Day this year and I am pleased with
    it. I also happen to have the same headphones as .0 mentioned and
    they too seem to work well. I am sort of disappointed at how shock
    sensitive it is. I used it when I went to San Fransisco on business
    two weeks ago and it was upset by only mild turbulence. 
    					
    						Jim

    I have a technical question about the D-4 and all the Sony portables,
    and this seemed like an OK place to ask.  All the players I've seen
    have a DC input marked 9V, however, Sony sells a car adaptor
    (cigarette-lighter plug-in) that uses this jack, and of course car
    batteries are 12V.  I'm assuming that this plug doesn't have a DC
    regulator circuit in it to drop to 9V.  Can the player withstand
    12V?  I'm asking because I plan to put in a permanent power cord
    from the car battery and I want to know if I should go find a zener
    diode.
    
    			Steve

    I have the Sony car mounting plate (CPM-100 or some such thing)
    and it definitely DOES have a power converter in the base.  Nine
    volts is what you get from the plug.  (Actually about 9.3 on mine.)
    Since most car batteries are really about 14.5 volts, not 12 at
    all, I absolutely would NOT run that direct to the player.
    
    As for what will cook a Sony player, all I can tell you is that
    the first D-15 I had came with a defective AC power supply that
    put out 22 volts.  This cooked the D-15 in a big hurry - about
    15 seconds.  Fortunately it was a Sony AC adapter, and Sony replaced
    the D-15.
    
    B

    As I stated in a previous reply, I've owned one of these since July.
    I've been using it quite regularly in my car powered by its internal
    battery. Recently I've been experiencing shorter battery life between
    charges. A couple of weeks ago it crapped out after about an hour
    and a half of use. This morning it dropped dead after only 45 minutes
    of use. Everynight I hook it up to my home system and the ac adapter/
    charger. Per the Sony instructions supplied with it, I've charged
    it even after very short uses. This seems contrary to my understanding
    and previous experience with ni-cad batteries (you know, memory
    effect). Has anyone else experienced this?
    
    Ken....
    

Re: .-1

>        Per the Sony instructions supplied with it, I've charged
>    it even after very short uses. This seems contrary to my understanding
>    and previous experience with ni-cad batteries (you know, memory
>    effect). Has anyone else experienced this?

    I don't know about the D-4, but earlier Sony Discman players used some
    form of sealed lead-acid battery, which could explain the charging
    instructions.

    Hope this helps,

    Ceri

    re: last two
    
    Yeah, the D-4 has lead-acid batteries too.  I just got a D-4, so
    I'm not real happy to hear that the battery pack poops out in under
    6 months.  You can buy replacements too, though.  Or you can buy
    or build an adaptor for the cig. lighter for car use, which is what
    I plan to do.
    
    				Steve

    I've had a lead-acid rechargable battery on my AIWA walkman for about
    a year now, no problems.

    The instructions on both of my Sonys (D-7, D-15) say that the battery
    can be charged between 200 and 250 times.  At about 1 charge per
    day that equals a little over 1/2 year...
    
    B

    My Sony battery started dying after about 6 months too.
    A friend told me, so you can take this with a grain of salt,
    that I should fully discharge the battery before I recharged
    it. This should "exercise" all of the charging power of the
    battery, and prolong its life. I've been doing this, and
    now I can get about 2 hours out of a fully charged battery,
    when before I was getting 45 minutes.
    
    Scott
    

    Well, for lead acid batteries:
    
    The number of cycles typically depends on the depth of discharge.
    Taking Gates Cyclon cells as an example with which I am familiar,
    100 percent depth of discharge will allow about 200 cycles while
    20 percent will allow 2000 cycles (or something like that, I don't
    have my data sheets handy).  Also note that this is to 85 percent
    of usable capacity, so if you don't mind short cycles you will do
    better.  Therefore, lead-acids should be charged after each use
    and float-charged when not in use.
    
    And for ni-cads:
    
    The usable capacity depends on the history of use, lots of shallow
    cycles will result in a battery that will only give shallow cycles.
    This "memory" effect can be cleared by several full cycles.  Thus
    they should be charged when they go dead, not after every use. The
    jury still seems to be out on the care and feeding of ni-cads when
    they are not in use, some people charge them frequently, some discharge
    them and store them, some store them with a short across the terminals,
    some buy new ones at the beginning of the season, and some make
    midnight sacrifices to pagan deities.  There doesn't appear to be
    any way to float charge them easily....
    
    Willie_who_just_built_a_float_charger_for_his_Gates_cells.

    The RC notes file has had many discussions on the care and feeding
    of nicads, look there for lots more info.
    
    Willie