Casio CZ/ VZ/ FZ - Pro Series

well sure, it's good to think about the amplifier draw.

BUT i'm not positive that a slightly (or considerably) low current
would be a problem in this case. i'm also not sure it wouldn't be.

the power amp in the cz101 is a sanyo LA4138. i can't find a pinout or
a detailed datasheet for this chip, but other chips in the LA4x series
are self-regulated, with max power output varying between like 2 and 4
watts.

i'd be very curious to know more about the LA4138, if you have any
more detailed information than "hey, didja know? amps draw power!"... :)

i'd especially be curious to know the pinout, cause then i could
determine the actual operating conditions that the chip experiences in
the cz101; without that it's a little hard to figure it out from the
circuit board (or even the schematic if i had one).

it'd be interesting to figure it out, cause there seems to be a couple
possibilities for mods: an external resistor to fix voltage gain (the
chip is reputed to have some kind of smooth saturation), a pin to
change the high-frequency response...

apparently there's an LA4140 series with the same pinout but i can't
find that either.

- eb


--- In CZsynth@yahoogroups.com, DJ Pat <djpat@...> wrote:
>
> Just some "common sense" for everybody...
> 
> Anything with a TRS (a 19th century technology) output socket on it
has an analog amp inside. The amount of juice you need to drive that
amp is going to vary according to what you are playing, how many notes
you play in a certain time frame, the velocity of those notes, etc, etc.
> 
> And more importantly, the analog amp is going to drain as much power
as it wants regardless of anything else going on inside the box.  And
if there isn't enough power, its going to suck up however much it can
get, leaving less than enough behind for the guts of the synth.
> 
> To get the best sound quality out of the beast, you are going to
want the volume as high as possible without distortion, and you need
to feed it an adequate amount of juice to provide that volume in a
CLEAN manner, meaning you are better off giving it exactly what casio
originally provided (or slightly more) than you are by under powering
it.  You can always turn the volume down and it won't need as much
electricity...  but then your signal to noise ratio gets worse...
> 
> 
> 
> 
> 
> ezra buchla <ezra.buchla@...> wrote:                               
  clues:
>  
>  my cz101 runs fine off 500mA.
>  
>  300mA didn't cut it.
>  
>  -eb
>  
>  On 8/2/07, Fulfil Objective <kasploosh@...> wrote:
>  >
>  >   Sweet math equation! I did a similar calculation myself last night
>  > and came up with almost the same answer.
>  >
>  > The thing is, most Casio keyboards will work form varying degrees of
>  > current and voltage. For example, I have a Casio MT-68, and the
>  > original adapter for it was 7.5V at 600mA. I cobbled together an
>  > adapter for it, by splicing a good plug onto a 7.5V at 200mA
power supply.
>  >
>  > 600mA
>  > -200mA
>  > ------
>  > 400mA - That's how much power (current) I'm missing.
>  >
>  > Using your sweet equation I find out that I'm missing 400mA. And yet
>  > it works fabulously. An MT-68 is not very computery though, and can
>  > run from lower power. If you lower the power enough it will actually
>  > play quieter, rather than not operate at all (I think).
>  >
>  > The CZ-101 needs more current, but I'm guessing it also has a
narrower
>  > range of operation. So the question is really: for people who have
>  > made their own power supplies, do you have any clue about the
range of
>  > operation in a CZ-101?
>  >
>  > Thanks!
>  >
>  >
>  > --- In CZsynth@yahoogroups.com <CZsynth%40yahoogroups.com>, PAJeff
>  > <pajeff@> wrote:
>  > >
>  > > 850mA
>  > > -210mA
>  > > ------
>  > > 640mA - That's how much power (current) you're
>  > > missing. I'm not surprised it doesn't work.
>  > >
>  > > Radio Shack has power supplies with multiple
>  > > plugs.
>  > >
>  > > PAJeff
>  > >
>  > >
>  > >
>  > >
>  > __________________________________________________________
>  > > Be a better Globetrotter. Get better travel answers from
someone who
>  > knows. Yahoo! Answers - Check it out.
>  > > http://answers.yahoo.com/dir/?link=list&sid=396545469
>  > >
>  >
>  >  
>  >
>  
>  [Non-text portions of this message have been removed]
>  
>  
>      
>                        
> 
> 
> [Non-text portions of this message have been removed]
>