Freerunner audio channels

David Fokkema dfokkema at ileos.nl
Mon Aug 10 17:05:10 CEST 2009


On Mon, 2009-08-10 at 14:15 +0100, Al Johnson wrote:
> On Monday 10 August 2009, David Fokkema wrote:
> > On Mon, 2009-08-10 at 15:53 +0400, Paul Fertser wrote:
> > > Alexander Shulgin <alex.shulgin at gmail.com> writes:
> > > > On Sat, Aug 8, 2009 at 14:05, Paul Fertser<fercerpav at gmail.com> wrote:
> > > >> David Fokkema <dfokkema at ileos.nl> writes:
> > > >>> The fact that Freerunners differ in audio quality and settings has
> > > >>> been stated on this list and on support. And going by the last
> > > >>> paragraph, this is true.
> > > >>>
> > > >>> So, _why_ are Freerunners different?
> > > >>
> > > >> One of the problems is that some freerunner revisions are in fact
> > > >> different in hardware. Most devices have 1uF capacitors instead of
> > > >> R3004/R3005 (which should be 0R), and that's not a joke. That is
> > > >> earpiece path and not surprisingly that devices that have those
> > > >> capacitors have considerably lower sound volume from the earpiece.
> > > >
> > > > And what do I do if I happen to have one?
> > >
> > > Tweak alsa state files appropriately. There's a routing diagram on the
> > > wiki that explains everything needed.
> >
> > If that doesn't really cut it, is it possible to swap the 1uF for a 0R?
> > Gotta make a list of hardware fixes to perform, ;-)
> 
> If you need to ask you probably can't do it yourself ;-) Schematics and 

No, I probably can't, :-/

> component layout are available, and shorting a cap shouldn't be too hard. The 
> components are small, and not far from the headset coupling caps. See sheet 3 
> of the component layout under the bottom right corner of U3001.

I'm privileged to be working at a national institute which has a pretty
advanced electronics lab. I've asked and they're willing to do this for
me. They already told me that shortening would be easier than swapping
components. However, they do this routinely and if I supply them with
schematics and a list of fixes (buzz, bass, recamping, earpiece, etc.)
they can probably do all this in one go. Components are already in
stock, too, :-)

David




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