Freerunner audio channels

David Fokkema dfokkema at
Tue Aug 11 21:53:29 CEST 2009

On Mon, 2009-08-10 at 20:06 +0400, Paul Fertser wrote:
> David Fokkema <dfokkema at> writes:
> > On Sat, 2009-08-08 at 15:05 +0400, Paul Fertser wrote:
> >> David Fokkema <dfokkema at> 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
> >
> > 0R's are placeholders for possible future modifications, right? Is the
> > 1uF capacitor deliberately (but mistakenly) inserted or is this a
> > manufacturing bug?
> The first :(

Hmmm... maybe the idea was to improve audio quality by inserting a
filter? Too bad it didn't work out that way...

> >> Unfortunately, there's no way to find out which devices are affected
> >> by this bug judging only by revision and serial number as BOMs were
> >> lost due to an incorrect file format conversion, one needs to actually
> >> try and see for himself.
> >
> > If I open up my phone (have to do it someday, right?) how can I
> > distinguish a 0R from a 1uF?
> Unlikely since those caps are under a can and dismounting it requires
> extra effort and you can damage something doing it.

How many cans are there inside a freerunner? I'll have to study the
schematics and really have to open this thing.

> >> AFAICT A7s are affected while at least some A6s (mine e.g.) not.
> >
> > Hmmm... that's bad.
> >
> > Are there many differences like these?
> I don't know of anything important except those fake 0Rs and that the
> bass was a bit improved in A7 (from 1uF to 4.7uF). If you're really
> that interested, ask Joerg.

Maybe I will, yes. Would be nice to have an exhaustive list. Probably
this can also be found in the core project.



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