[Elecraft] K3 ssb sound revised

[Jim Brown]

On 12/2/2010 9:50 AM, Mike Rodgers wrote:
> I failed to mention it's the sound on receive and not transmit that concerns me.most are telling me it's nothing to worry about.

I would generally agree with that.  The RX in the K3 is excellent, the 
IF filters are excellent, the audio chain is quite clean, and there is a 
graphic equalizer that allows you to tailor the response to your 
speaker, earphones, and ear/brain.

The only possible criticisms  I can think are

1) the audio output stage is relatively low power, so if you have a 
problem with hearing loss, or if you want to use it with either speakers 
or headphones that have low sensitivity, it may not be loud enough for 
you.  I'm 69 years old and have a fair amount of hearing loss, but I've 
never run into a situation where I wasn't very pleased with what I heard 
from the K3.

2) Early production K3s had 600 ohms in series between the output stage 
and the line output transformer. This was a lousy design, and caused the 
output transformer to create distortion.  I'm told that a running 
production change reduced the value of those resistors to the minimum 
value needed to provide circuit stability, which has been good 
engineering practice in the pro world for at least 30 years.  Note that 
this affects ONLY the line out, not the speaker or headphones, each of 
which have their own output stages.

73, Jim K9YC