GSM-noise "buzz" issue

Joerg Reisenweber joerg at
Thu Oct 30 16:30:05 CET 2008

Am Do  30. Oktober 2008 schrieb Ole Kliemann:
> Thanks for the answer!
> The point is, i certainly won't do the fix myself. ;) I will send my
> device to my distributor on warranty.
> On Thu, Oct 30, 2008 at 12:11:47PM +0200, Joerg Reisenweber wrote:
> > Seems you always could "upgrade" to the 'botch' fix found in A7 (It 
> > work, as our TPE engineers found it worth to implement in A7 ;-):
> So as this fix is officially approved,

That's *your* way to read my words ;-)
My posting contained nothing official nor any approvement.

> I assume my distributor will 
> either be able to apply it or provide me with an A7. Gonna check with
> them soon.
> > > And - if you allow me to be off-topic - is there any improvement fix for
> > > the headphone jack? I mean this hipass-filtering issue making music
> > > sound quite tinny.
> > a) place some decent 100uF (or as high cap as feasible) parallel to C4110 
> > C4111. Make sure you don't create another contamination path for RF 
> > inside big can - maybe use a ferrite ring to block RF next hole where you 
> > route some wires from those big caps inside can to C4110/11.
> > b) *short* C4110 / C4111, and insert the 100uF somewhere else in 
> > b1)e.g. near R4405 / R4407 (you can even replace these R by 100uF 
> > capacitors).
> > You should remove R4117 and R4117 then, and instead place these 1k from 
> > JK4401:pin2 and pin3 (! for JACK_INSERT function) to GND
> > b2) or even place the 100uF outside FR in the housing of your hs-plug or 
> > 2.5->3.5mm adapter
> Is this somewhat official? 

> Is it included in any newer revision? 
For sure not, as any "official" fix (that may or may not be included in A7, 
I'm pushing it but result is somewhat... hmm, limited) for sure simply will 
rearrange layout to make space for decent 100uF in place of the former 1uF 

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