Can we fix the audio for A5/A6/A7?
andy at openmoko.com
Wed Apr 2 15:32:30 CEST 2008
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Somebody in the thread at some point said:
|> They're ~32R apparently, with 33R in series (R4405 / R4407) so it is
| Yep, so *no* standard replacement headphone will fit. No Motorola, no
| just OM-headset (as long as at least these have 600~1000Ohm for
| No use to tell in wiki about the standard pinout of connector.
I googled around but I didn't find any information about what is common.
~ Yeah it would be better to be compatible for sure, but we do ship 32R
|> So the impact is we lost some bass end... maybe not a noticeable amount
|> to what we would have with 100u due to the transducer performance.
| We have a f0 of ~160Hz WITH OPEN CIRCUIT, just due to the 1k pulldowns!
| With a 1000 Ohm headset, this will be 320Hz for -3dB!!!
| That's noticeable for sure. It's plain crap.
We don't ship 1K impedence headset, since we didn't target it we just
have to look after what we did ship with.
|> there's no room for adjusting the value of the caps on the A5 or A6 PCB
|> then I would just accept this.
| At very very least we can increase the thing to 4.7u, it fits on
Allen can say yes or no to this, but I think first he would try it both
| Think one of my first tasks in .tw will be retrofitting the 100uF and
| the sound. Maybe i can do a nice foto footage for the wiki, so anybody
| good soldering skills can do the same, if they are interested in HiFi.
If I had a clue about the ALSA profile end I would try it for you.
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