Re: [Alsa-user] arecord: set_params:1239: Channels count non available

[Roger <rog...@gm...>]

> On Tue, Mar 18, 2014 at 08:47:38AM +0100, Clemens Ladisch wrote:
>Roger wrote:
>> I keep getting the following error whenever specifying -c 1 or --channels=1, or
>> specifying any number of channels less than two channels when using an ASUS
>> Essence STX soundcard and recording using the microphone line having a TRS
>> jack.
>
>The CMI8788 chip supports only channel pairs.
>
>> If I'm not mistaken, the jacks are wired to detect when a TS or TRS phone jack
>> is inserted.
>
>There is no such detection.  When "Line" is selected as capture source,
>the input jack is routed directly to the ADC; when any other sources are
>selected, the inputs are routed through the analog section of the
>CMI9780 chip, which then acts as a microphone preamp and mixer.

Thanks for the clarification.

I think I just noticed this yesterday after plugging in a XLR microphone using 
a TS (or two conductor) phono jack into the combo Microphone/Line Input of the 
Xonar card.  Since the microphone worked, I speculated 5 volts was still 
somehow getting to the microphone in some fashion, regardless of using a TS or 
TRS connector.

Further testing has also proven the microphone boost has not affect to the line 
input or when switching to Line.

This has helped greatly, as I'm now set to further test using a ART Tube MP 
Studio (V3) pre-amp for amplifying my XLR microphone connected to the switched 
Line/Microphone Input of the Xonar card.


-- 
Roger
http://rogerx.freeshell.org/