K&K Audio / Lundahl Transformers: RE: Follow up by Michael V

Dave/Kevin:

I tried the grounding change but it had no impact. To clarify and restate the problem, the issue is static noise that only appears in silent passages like the beginning and end of songs. It only exists with my Sonos source (consistent for various streaming services like Spotify and Tidal), as playing CDs has never had any issue in 10 years of use.

I amazingly aquired a new old stock RAKK board (version 1.1, same as mine) which had never been installed. So far, there is zero noise. I'm hopeful there was just a component failure on my RAKK board, but since the issue only presented itself after 6 months' use with the Sonos, I'm only cautiously optimistic.

So, two questions. First, does it make sense to send the "noisy" board for a diagnostic? Second, does the latest RAKK board have the same physical footprint as mine? I have zero clearance on the width in my current chassis. I'm just wary of the noise coming back if there is somehow an incompatibility between the Mk I board and Sonos, or even simply a long-term reliability issue with the Mk I board.

Appreciate any thoughts.

Thanks, Michael