seanadams Wrote: > If looks like the headphone amp chip itself (not surrounding traces) is > susceptible to picking up the 802.11 signal (it does not appear to be > DC power related).
So that's a 2.4GHz signal? If it was an RF circuit, I'd say maybe one of the traces is acting as a nice 2.4GHz antenna. (1/10 lambda would be about 1.25 cm.) However, for this audio amp, it seems you'd have to get that noise down into the audio range to hear it. (I'm not an RF guy; just speculating.) Maybe the noise is actually from modulation of the 802.11b/g signal? Here's a thought: If the pop/buzz with each clock tick (once per second) is reproducable, you could trigger a (digital) scope on that and (maybe) get an idea of the frequency of the noise. Maybe the antenna is a secondary effect, e.g. it's acting as a receiver for a lower frequency signal (maybe noise from accessing a memory, for example, or the modulation mentioned above) and re-transmitting. Still, you need to be able to pick it up again in the audio amp section... I also wonder if the Standby/Shutdown pin would be a convenient place to inject some noise. Well, it looks like an interesting problem to debug. Dang, I gotta stop reading threads like this; it's very hard to resist opening the box ;) (I've been going by the photos.) - Dave -- Dave D _______________________________________________ Discuss mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/discuss
