[Elecraft] Elecraft AF1 audio filter

[dw]

Hi Johnny,
You may try seeing what a choke coil in series with the audio to the
speaker or headphone does for you.  I have the Nescaf filter and really
like it for CW.
In most cases, its cleaner than the available internal audio filters.

But I found that adding a 3mH coil and 15uF cap in series (set for
750hz) makes a significant improvement removing harshness.  

I keep my K2's widest filter as wide as it will go, and the coil takes
care of most of the harshness.

A suggestion for you to check out if interested :-]
N1BBR