[Elecraft] K3 Audio: from OK to superior

[Jim Brown]

On 7/17/2014 8:19 AM, Ignacy wrote:
> I thought that headphones are headphones and their main differences are
> frequencies characteristics, sensitivity + fit. However, with OE the sound
> quality is greatly improved. Any idea why?

Several possibilities.

How old are you? How much hearing sensitivity have you lost due to 
exposure to loud radios, loud music, noise at work, use of firearms? The 
audio output stages in Elecraft radios are not designed to produce the 
very high levels needed to overcome a lot of hearing loss, and may run 
into distortion when asked to do so. Wayne designs them this way to 
minimize current drain -- all of his radios are designed to be good 
back-packing radios too.

I worked in pro audio for a lot of years, so I have hearing loss both 
from that and from my years in ham radio. The output stages in my 
Elecraft radios are good enough for my hearing loss, and my expectations 
of what a ham rig should do, but they may not be good enough for everyone.

All headphones are not created equal, even good ones. Their load 
impedance and voltage sensitivity can vary over a wide range. The Bose 
headphones may have greater voltage sensitivity, so the Elecraft output 
stage doesn't have to work as hard.

One thing that all of us can easily do is use RXEQ to get rid of low end 
noise that is of no use for communications, but burns some audio 
headroom. I have RXEQ in my KX3 set to max cut on the three lowest 
bands. Cutting the two or three lowest bands on a K3 would probably help 
headroom by about 2 dB.

73, Jim K9YC