[Elecraft] K3 Yamaha CM500 vs Koss SB40

[cx7tt at 4email.net]

My CM500 was looking kinda 'ratty' after 4 yrs with ear cushions
starting to shed material. Saw where someone said that Koss actually
makes the CM500 for Yamaha so ordered the SB40 as replacement.

First trial was CQ WW SSB a couple of weekends ago.  Rig had been
sitting in the closet for several months so brought it out and coupled
with Buddipole, 6ft out the window of 24th floor apartment here in HP.
Audio reports were terrible including those from guys who knew my
voice...I had to 'close talk' the SB40 with mic touching lips....using
VOX as could not find the foot switch adaptor for the Heil footswitch.
Vox had never been an issue as I have used VOX on the K3 for 7 years
with no issues...best Vox I have ever experienced....audio was so bad,
one guy suggested to turn down the drive on my amp....I was running
barefoot K3/100 @ 90w.  Found CM500 in packing box and got it
going....audio became the usual outstanding.

So, what is the difference between these two headsets and what can I do
to properly use the SB40?

BTW, the Buddipole/CM500/K3 combo was great...due to proximity to
building, could only use BP on 10 and 15m...worked over 600Qs in 3 hours
on 10m on Sunday pm......great fun.

Suggestions for using the SB40 w/K3?

73 Tom HP1/K6CT aka CX7TT