solved? Re: [linux-audio-user] [OT] recording levels (mismatch)

[anahata]

On Fri, Oct 15, 2004 at 08:19:36AM -0700, Erik Steffl wrote:
 
>   sony STR-SE581
>   voltage 150mV
>   impedance 10kOhms
> 
>   the creative.com knowledge base search revealed:
>   Line In Full Scale Input 2.0 Vrms
>   Line In Impedance 10k ohms
> 
>   what is Vrms? I guess it has something to do with voltage... should 
> 2.0 Vrms play nicely with 150mV?

Root Mean Square, which technically means the DC voltage that develops
the same power in resistive load as the AC signal would... a sort of
average and a reasonable way of comparing volume levels.

No, it wouldn't play nicely - your 150mV output is, as shown, rather low
for an input that expects 2V and that explains ithe low levels you are
seeing.

>   looks like headphones output works pretty well. I don't get 
> unprocessed signal (i.e. volume, treble/bass, effect (dolby, room 
> type...) etc. are all there so I have to be careful about the settings 
> on the receiver) but the signal is strong enough (matching what 
> soundblaster expects).
> 
>   any comments? gotchas?

As you say, the volume and other controls affect it - but that's the
only problem, and you can live with that - just don't touch them once
set up correctly!

-- 
Anahata
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