75 Ohm Cable Upgrade Cleared RFI Noise

[Pio]

I live in Weehawken NJ right across the river from NYC and I had been experiencing pretty nasty radio frequency interference on my VPI Scoutmaster set up since we moved here about one year ago. It was noticeable from the seating position once the volume knob was turned up more than 1/4 turn.

I thought it might be my phono pre amp (Moon LP5.3) even though I run XLR cable from it to my JC2 pre amp and XLR rejects noise very well. I was jonsing to upgrade to a "better" phono pre-amp as I was certain this was the cause of the problem.

It wasn't!!

An engineer from the radio station I work at suggested I use 75 ohm solid core wires terminated with RCAs instead of the stranded wire / typical RCA with less insulation - promising that would help.

IT DID! BIG!!!

The clarity is noticeable, especially between tracks as now I don't hear the RFI!!

Next step, connect the ground cable. But I didn't have one, so I decided to pull the stock VPI cable apart a bit and grab the ground wire.

This is what I found (pics below)- very high quality wire, but the stranded nature was introducing a ton of noise. I'm not saying replace the stock cable with an expensive cable, my replacement 75 ohm cables are fairly inexpensive, but boy did the 75 ohm cable improve upon the noise rejection of the stock one! If you are having RFI problems, try this!!



Stock RCA cables that came with my Scoutmaster




the ground wire is soldered between the left and right cable - so it does't go all the way through (as I thought it would) from one side to the next.






The wires inside the stock cable



Had to stand the pre amp on its faceplate as the ground wire is fairly small, will get a longer cable tomorrow.