Phono amp RFI problem


Hi everyone,

Just added the amazing LFD LE/SE phono stage to my system.  It sounds great, but it picks up local radio stations (clearly enough that I know there's a sale at the local boat shop!). I've tried moving the unit around, but it still picks up the signal.  I'm using a Silnote phono cable, and I've never had this problem with any other phono stage.  Any suggestions on how to deal with it?  

Thanks, Scott
smrex13
Perhaps I should have provided further info on the system:  VPI Traveler with ground wire connected to the phono amp.  LFD Mistral integrated amp, JW Audio ICs from the phono amp to the Mistral.  JW Audio speaker cables to JM Reynaud Silver Bliss speakers.  Help!

Thanks, Scott
Hi Scott,

This thread and this one describe several approaches that you can try.

Best regards,
-- Al
Thanks, Al. A short term solution I just figured out was to braid the phono cable - that seems to have stopped the radio station from getting through, and there’s only a slight bit of hum. Will read through the threads and experiment a bit tonight after work.

Scott
If the phono section has RFI problems, it really should be something addressed by the manufacturer. Its a bit of homework that only they can address correctly. I know you may have a solution, but the fact is if the preamp is sorted out correctly (made RFI immune) it will also sound better and likely will seem quieter.

You could try ferrite ring(s) and wrap the phono cable through it several times. This is a easy fix if it works.  Also, you can braid the cart. leads of the tonearm prior to connecting to the cartridge pins, but be gentle. 

If there was a phono RFI/EMI issue I've had it or have it. I can't use a SS phono preamp in my system. I'm just glad I found that tubed phono's defeat most of the RF/EM issues I have.  I still have issues but they are manageable now. 

I've always preferred tubed phono stages, so I might go back that direction.  The two phono stages that picked up the most RFI have been SS in my rig.  

Thanks, Scott