[Elecraft] Funny audio output in kx3

[Pentti A J Pajunen]

Hi'ya all!

Have any of You bumped with a phenomenon of KX3's audio output when 
using headphones or xternal speaker with amplifier (TBA 820), sounding 
like ghost-like space sound. This phenomenon doesn't xist when my rigs 
own internal speaker is in use. The funny sound gives me an expression 
of leak of sampling glitches from the processor. Is there some kind of 
possibility of bad or broken grounding inside the rig. Unsuitable input 
impedance of the external spkr amp, or bad headphones?
My K3 once sounded alike, but was healed by upgrading the software.

Any ideas for fixing?

73 & CU
Penna OH2G, OH2CG