#1515 HIGH CTest: Mic too noisy

[Zarro Boogs per Child]

#1515: Mic too noisy
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  Reporter:  Carla        |       Owner:  wad  
      Type:  enhancement  |      Status:  new  
  Priority:  high         |   Milestone:  CTest
 Component:  hardware     |     Version:       
Resolution:               |    Keywords:       
  Verified:  0            |  
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Comment (by arjs):

 I connected a set of external amp+speakers to the line out / headphones
 jack and switched on the mic on the XO. I turned the volume of the ext amp
 to a maximum and I could not hear the same noise that one hears when one
 records from the mic. In fact the sound was surprisingly very clear and
 noise free.

 This at least tells us the power supply is clean and the mic is noise free
 and the mic is biased properly.

 In this configuration the ADC is not actually doing the conversions (refer
 block diagram of AD1888 on first page of data sheet) and therefore, the
 noise is being introduced in the A to D conversions...

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Ticket URL: <https://dev.laptop.org/ticket/1515#comment:5>
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