[Elecraft] K3 DSP AGC Question

[Grant Youngman]

>> 
>> I was very disappointed to read your post. I purchased a Proset headset
>> directly from Elecraft when I bought my K3. According to Heil this headset
>> has an impedance of 200 ohms. Is that why I have to plug my headphones
>> into the rear speaker jack to get sufficient audio output from them? Why
>> would you folks sell a headset that does not complement the K3? I am
>> really disappointed.

There are two factors here.  One is impedance.  (The impedance actually presented by a headphone is frequency dependent and can vary widely from the "nominal" value).  The other is sensitivity.  

I regularly use 250 ohm headphones on the K3 with no issues whatsoever.  Why?  They require very little drive to reach an acceptable output level.  So even given their relatively high Z (compared to 32 ohms)  it isn't necessary to drive the output stage of the K3 into clipping or high distortion levels to get plenty of good audio.

I have a set of high end audiophile headphones with 62 ohm Z.  I don't use them on the K3 (tried them once).  Why?  It takes a whole lot of power (relatively) to drive them to reasonable listening levels.

Given the number of people who use Prosets and seem to like them just fine, I don't know why there would be any real concern or any reason to feel disappointment.

Grant/NQ5T