[Elecraft] Audio Output Impedance of the KX3

[w7aqk]

Jim,

Maybe you could expand on that somewhat as I'm still confused a bit. 
Perhaps I'm not understanding what I hear, or why, but it almost always 
seems that when speakers (or headphones) are not closely matched to the 
designed impedance I notice some deterioration in output.  Some mismatch 
doesn't seem too serious, but when the difference is high, it seems much 
more noticeable.

On the other hand, I've also experienced that using headphones with higher 
sensitivity ratings (like most Sony ear buds) tends to provide much higher 
output.  Most ear buds tend to be 32 ohm (16 at lest), but I find Sony ear 
buds usually work best as many of them have sensitivity ratings up 
around -108 dbm.  I could very well be fooling myself!

This topic was covered somewhat similarly back when folks, including me, 
were complaining about poor audio output from Heil headphones.  The 
headphone portion of my Yamaha CM500 works a lot better than my Heil, but 
neither works as well as some ear buds.  I don't really have another good 
pair of headphones around here to try.

Also, it was interesting to see Eric's response to this question.  He 
indicates that the rigs are spec'd at 4 ohms, and that 8 ohm speakers would 
diminish output somewhat.

Anyway, maybe you could make this all a bit clearer.

Thanks,

Dave W7AQK


From: Jim Brown <jim at audiosystemsgroup.com>

On Mon,1/23/2017 9:22 AM, Walter Underwood wrote:
> For portable operation, I use Apple EarPods. Those are 45 Ohms.

Don't worry about impedance of headphones. There is no need to match
impedances in audio circuits.

73, Jim K9YC