[Elecraft] LINE OUT output too low?

[Matt Zilmer]

Thanks, both Paul and Jim for this information.  Very useful and I'll
update my knowledge base with it!

73,
matt

On Wed, 17 Dec 2008 08:45:53 -0800, you wrote:

>On Wed, 17 Dec 2008 07:28:32 -0500, Paul Christensen wrote:
>
>>> "FWIW, standard Line Out is 1Vp-p at 600 ohms line impedance.  matt"
>
>>I think you'll find standard, nominal "Line-In/Out" consumer levels to be 
>>referenced to -10 dBV irrespective of Z, where 0dBV = 1 Vrms. 
>
>Yes. 600 ohms has not been part of audio practice, pro or consumer, for at 
>least 40 years. ALL line level and mic level audio circuits, pro and 
>consumer, are low impedance source, high impedance termination. The signal 
>is transferred as a voltage, not as power or current. Typical output 
>impedances are on the order of 100 ohms, input impedances are typically 
>10K for pro line level, 50K for consumer line level. 100 ohms is chosen 
>primarily because it is a good value for isolation of op amps from the 
>capacitance of the cable that it drives. This capacitance can be 
>significant in pro installations, but rarely in consumer applications. 
>
>>This standard started with the old IHF, merged into EIA, and then 
>>somewhere along the way I believe AES became the recognized 
>>standard-setting organization in North America.  K9YC would know
>
>I can't speak to the history of these standards, but The AES Standards 
>Committee is an international body, of which I am a member. 
>
>>-10 dBV is equivalent to 0.316 Vrms.  If we assume a worst-case 10 dB 
>>peak-to-average ratio (and probably a lot less depending on the K3's AGC 
>>menu settings), then the maximum distortion-free signal voltage handling 
>>required is 0 dBV or 1 Vrms or 2.83 Vp-p.
>
>Yes.
>
>For those who are interested, there's more on this in the tutorials on my 
>website. http://audiosystemsgroup.com/publish
>
>73,
>
>Jim Brown K9YC
>
>
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