>In a message dated 11/8/99 1:17:53 PM, [EMAIL PROTECTED] writes:
>
><< I am writing for the first time to this list with a question
>about a peculiar circumstance of popping new Global Village 19.2
>duo modem into a 2300-upgraded 280c. >>
I managed to miss the original posting with the full description of the
problem, but if the reference is to too-loud clicking and popping noises
from the modem in a PPC-upgraded Duo, I may be able to shed some light. I
upgraded a 270c and found the speaker much too loud with the new
motherboard, particularly with respect to the modem. Some research turned
up the fact that the stock 2300c uses a higher impedance speaker than
either the 270 or 280 did; the PPC motherboard and older speaker are
essentially mismatched. I was able to fully correct the problem by opening
the display shroud and soldering a small variable resistor in series with
the speaker, then tweaking it until the volume range was to my liking
(between very quiet and moderately loud). A small bonus from this change
should be slightly decreased power consumption when the speaker is in use
(and that may be why Apple changed the speaker spec to begin with).
Be warned that messing around in the display is not minor surgery, that you
need a very small variable resistor to fit in the space available (but I
found one at Radio Snacks without any trouble), and that worst of all, I
draw a complete blank on the proper impedance to use. It *may* have been a
1-100 Ohm pot, but take that with a large grain of salt - I'm a software
type, not an electrical engineer, and I went on someone else's good advice
and estimate of the impedance change between Duo models (possibly someone
who's now on this list, though this all took place before the list
existed). Also, I believe the 280c and 270c already used slightly different
speakers, and the volume increase is less after upgrading a 280c (so this
intervention will require a smaller increase in impedance).
--
Marc Sira | [EMAIL PROTECTED]
"If you can't play with words, what good are they?"
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