[Elecraft] K3 LINE Out mixes KRX3 and main output?

[Joe Subich, W4TV]

> The microKeyer II, for example, has the Master control grayed 
> out but the left and right channels are independently adjustable.  

Correct, microKEYER II uses the Micronas UAC2556B codec which has 
independent left and right attenuators for the line input.  Some 
operating system drivers show them as independent controls while 
some map them as a gain/balance pair.  The Micronas also has a 
single channel (left channel in the USB data stream) mic input. 

> My digiKeyer uses the Burr-Brown PCM2902; when using Core Audio, 
> there is no master, left nor right controls.

All DigiKeyers use the TI (Burr-Brown) PCM2902 CODEC.  The TI has 
a single dual channel audio input.  There are no electronic level 
controls on the input (chip design).  I'm not aware of on-chip 
attenuators on any of the TI/BB USB products. 

73, 

   ... Joe, W4TV 
 
 


> -----Original Message-----
> From: Kok Chen [mailto:chen at mac.com] 
> Sent: Sunday, February 01, 2009 12:40 AM
> To: Elecraft Reflector
> Cc: Leigh L. Klotz, Jr WA5ZNU; lists at subich.com
> Subject: Re: [Elecraft] K3 LINE Out mixes KRX3 and main output?
> 
> 
> 
> On Jan 31, 2009, at 9:16 PM, Joe Subich, W4TV wrote:
> >> For the device in question, Griffin iMic, this doesn't 
> seem to be the 
> >> case. It does not separate enumerations for independently setting
> >> left
> >> and right input gain. It does support stereo input, just not two
> >> mic/line gain controls.
> >
> > I don't know about the iMic - Chen would though.
> 
> It depends on the generation of the Griffin Technology iMic.
> 
> I have three generations of iMic, dating back from more than 5 years  
> ago.  The are the grey disk shaped ones, not the current-generation  
> white ones.
> 
> The oldest one had a 20 bit input codec, with no digital attenuator,  
> no left, no right, no Master.
> 
> The next generation is also 20 bits, but it has independent left and  
> right attenuators (as seen from Core Audio -- I don't use 
> Port Audio),  
> but no master attenuator.
> 
> Both of the above have 20 bit codecs in them, but uses the USB Audio  
> Interface class and you can only see 16 bits (they don't need 
> special  
> drivers, but you also don't see 20 bits, HI).
> 
> After that (and I believe it is true with the white bodied 
> ones) they  
> went to a 16 bit codec.  Mine (still a gray body) only has a master  
> level control but no individual left and right controls.
> 
> If you are using Mac OS X, the easiest thing is to launch the Audio  
> MIDI Setup utility that is in /Applications/Utilities.  Audio MIDI  
> Setup also uses Core Audio.  There are three slider associated with  
> each sound card's "volume," a Master slider, and channels 1 
> (left) and  
> 2 (right).  If a control is not available, it will be grayed out.
> 
> The microKeyer II, for example, has the Master control grayed 
> out but  
> the left and right channels are independently adjustable.  My  
> digiKeyer uses the Burr-Brown PCM2902; when using Core Audio, 
> there is  
> no master, left nor right controls.
> 
> 73
> Chen, W7AY
>