no-cap bass fix

Stefano Cavallari stefano at cavallari.cjb.net
Tue Mar 23 14:14:37 CET 2010


Yesterday night I was going to fix the poor audio response of the Freerunner.
Just before starting to solder (having opened the phone and the metallic 
plate) I discovered the caps I got were the wrong ones.
So I looked at the scheme for an alternative solution, and I decided to try to 
replace the audio caps with 0R, thus losing DC blocking.
The plan was to measure the DC component and if low enough, leave it as it.
If not, putting the DC filter in the minijack adapter.
So I did that, and it seem to work. I tried first with a multimeter. It reads 
0.2 V DC, but I have to confirm it with an oscilloscope.
I tried the audio with very cheap headphones first (I was afraid of burning 
them), then with decent ones. It seems to work way better!
Now I just need a better adapter cable (mine need to be inserted middle way, 
it's not the right one), and then I have usable audio :)
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