[sound]: capacitor that act like a high-pass filter and so removes the bass on the headphones jack

Andy Green andy at openmoko.com
Fri Nov 28 19:50:50 CET 2008

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Somebody in the thread at some point said:

|> | Hmm... why does it distort the interal speaker?
|> With the caps the transducer experiences -~1.5V .. +~1.5V worth of
|> deflection "down" and "up"; without the caps it experiences 0 .. ~3V
|> worth all "up".  So it's physically unable to deflect enough linearly I
|> would think.
| Please note the internal speaker isn't connected via the 1uF capacitors.
| See "SPK LOCATION:41XX" page6 schematics GTA02.

That's true.

| A short to GND when applying the silver-varnish on the other hand
might cause
| the distortion you have heard.

It's generally possible (you don't suggest what is shorted) but I wonder
if it can be more that there is 65R DC path to 0V on U4101 LEFTOUT that
wasn't there before the caps were shorted in the case the headset is in.

Is the internal speaker still distorted if you remove the headset from
the socket?

- -Andy
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