Remove Radio Station Background Noise
What is the best way to remove radio station sound from the TT feed to the pre amp?
When I turn the volume up to about 50% I can hear radio station noise if my ear is next to the speaker.
I started using clamp-on ferrite chokes that clip around the cables from the TT to the phono preamp to eliminate the noise. I wanted to know if there is a better solution or if the ferrite chokes compromise the sound.
The TT is a VPI Classic 3. The phono preamp is a Sutherland PhonoBlock and the pre amp (DMC-30SV) and amps (DMA-400) are Spectral Audio. All cables are MIT Oracle MA-X.
Dear @bigby : Really good system you own including your Benz Micro cartridge.
Well, obviously that something in your system is " acting " as an atenna when using the low level signal of a MC cartridge.
" or if the ferrite chokes compromise the sound. "" No, normally does not degrades the quality sound and you can try changing a little the TT orientation/position and the IC cables too. Sometimes these works, you can test it.
Regards and enjoy the MUSIC NOT DISTORTIONS, R.
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@bigby , I have this itch that tells me the problem is with your preamp. Spectral equipment is designed intentionally very broad band and is notorious for this kind of thing. I have a friend that dumped his Spectral system for McIntosh system. The preamp had a problem so he sent it back and hooked up an older preamp. It burned the Spectral amp right up. Torched! So, he had to send that back and you do not want to know what he paid to have that fixed. McIntosh has a reputation for reliability. So, he was not taking any more chances with newer electronics companies. Mind, the Spectral equipment sounded wonderful. Do not try to use the Spectral gear with anything else. But, it might be interesting to try another setup, even an integrated. Otherwise set up the Spectral gear someplace on the other side of the house. I'd bet it stops or has a much lower volume. |
Sometimes there is nothing more you can do besides ferrite beads. Not that I recommend them, but they can work if done right. The problem isn't your cable (XLR or RCA), the problem is RF signals (radio) are getting into your phonostage and it is demodulating them. You must low-pass filter the signal BEFORE it hits silicon (transistor, fet, opamp)! Radio demodulation is all happening at the input of the first stage. The output of that stage does not have enough bandwidth to amplify RF. PN junctions are the culprit, even parasitic ones. Tube phonostages do not have as much of a problem. The cure that I use in many of my designs is an RC low pass (set above 100kHz) right before the first semiconductor junction. This is sort of what your ferrite is attempting to accomplish. |
