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

Joerg Reisenweber joerg at openmoko.org
Sat Nov 15 18:30:32 CET 2008


Yes, sounds like a good idea (input impedance should be (much) > [&GT] 1000Ohm 
though, not <1k)
This adapter also could implement some hw-equalization for the highpass-filter 
created by the 1uF*(1/(1/1k + 1/(33R + adapter-impedance)). (where, in 
sequence, values are from: C4111:1u, R4117:1k, R4407:33R. Right channel 
analogue)

Requests for assistance welcome.
cheers
jOERG

Am So  16. November 2008 schrieb Scott Carlson:
> Would also be possible to create a small inline adapter for head set that
> have <1k input impedance? It may be convenient to make a batch and sell them
> cheap? (As a non-intrusive) hw fix.?
> 
> SCarlson
> 
> 
> >
> > Sorry the audio is definitively broken due to the capacitor issue you're
> > mentioning. There is no sw-fix either.
> > You may get (semi)decent audio by:
> > o- using a home-stereo line in, which has >1k input impedance
> > o- using high impedance headphone (>600 Ohm)
> > o- do a rework on the capacitors (there are different ways to do that, all
> > need excellent soldering skills)
> > o- use a bt-headset
> >
> > very sorry I didn't achieve to fix this for MP yet
> > cheers
> > jOERG
> >
> > _______________________________________________
> > hardware mailing list
> > hardware at lists.openmoko.org
> > http://lists.openmoko.org/mailman/listinfo/hardware
> >
> >
> 


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