Humm, I think Josh is talking about a mic pre.  These are beasts, and 
get into all kinds of squirrleyness.  I'm working on one now, and just 
discovered where a 490hz (and all harmonics thereof) noise spike in the 
FFT was coming from: the current used when blinking the "heartbeat" LED 
was inducing noise at -110db from the test signal.  (this preamp has 
digital control, and therefore has a PIC...)

J

William Chops Westfield wrote:

> On Sep 1, 2005, at 8:21 AM, Josh Koffman wrote:
> 
>> It's not so much the opamp I'm worried about. It's more that my analog
>> skills aren't so great, and as such I'm worried that my design,
>> layout, and component selection may impact the quality of the audio
>> signal quite a bit.
>>
> While I share your "fear of analog", I don't think the sort of
> strong-signal, audio frequency, moderate quality application we're
> talking about here should be TOO difficult...
> 
> BillW
> 
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist