[Elecraft] K2: Audio hiss in headphones w/ KDSP2...

[Steve Kallal]

I posted this question before and never got any response.
 
I have a K2/100 SN 2289 w/ the KDSP2. There is a definite soft hiss in the headphone output. It disappears completely when putting the KDSP2 into bypass mode. So I know it is from the DSP and not from QRN. I use the K2/100 almost exclusively for CW. The hiss often covers a weak signal particularly when the RF gain is turned down. The hiss doesn't seem to be a problem through the speaker. I rarely listen wo/ headphones. Switching headphones has not made any difference.
 
A search of this reflector's archives has produced an older thread on the topic. But there was not a definite fix for the problem. One suggestion was to put a shunt capacitor across the headphone audio line too act as a low pass filter. That might be OK for CW, but could be a problem w/ SSB.
 
Please let me know if someone has this problem or has resolved it.
73,
Steve N6VL