C7 Figure of Eight RFI

 

Bottom, single sleeve C7; top, double sleeve C7.

New York Diary (20-30): RFI and the Power Cord (C7)

One day, while streaming I heard a faint but discordant strand of music in the mix. I paused the music and found the RFI picking up radio. I stepped closer to the loudspeakers and could hear the DJ talking. Highly irritating. It was not a constant but would happen randomly.

I was pretty sure it had something to do with the Micromega MyDAC, which has a SM type supply. I swapped out the Kimber KCAG (braided 3-strand silver) for a shielded cable - no use. And so it went on for a couple of days.

Yesterday, not being able to find my spare ferrite ring clamp, I decided to swap the power cable. The small Micromega uses the figure-of-eight (C7) connector. The cable I had in has a thin flat sleeve (bottom one in pic). I exchanged it for one double its thickness, with the 2 conductors running side by side in separate sleeves (like a lamp cord). Voila! RFI elminated! So the replacement has better shielding!

Just a vignette...

Basic Repertoire Brahms wrote 2 beautiful Piano Concertos, which are among his most passionate works. Concerto No. 2 unusually has 4 movements. The Andante (starting 27:38) is most lovely for its dialogue between the orchestra (especially the solo cello) and the piano. Yuja Wang plays with the Munich Philharmonic under Valery Gergiev, during their Japanese tour.