high frequency intermittent noise
I put the PS Audio Noise Harvesters on the Furman P-2400 IT to see if they would stop blinking, they did not. And when I turned on my light on a dimmer in the kitchen (different circuit), the PSNHs went crazy. So does the Furman even do anything to filter noise? The noise floor in the music has been lowered. There is benefit sonically in the music though. |
james1969 OP @james1969 My idea to try the radio was to see if the noise was on the AC mains lines. From your post it appears the noise is not on the AC mains power lines. I am not quite sure though why you didn’t pick up the noise on the battery powered radio though. I suppose the static sound of the radio off station might have drowned out, masked, the signal noise you were listening for. If the noise is being radiated through the air it could be near impossible to totally filter it out. If at all. There are line filters, ferrite beads, and filter capacitors, that are designed to block unwanted signals. Problem is one size does not fit all. You have to know the frequencies you are dealing with to filter them out. I am not sure who you would need to hire for that. Al, (almarg), might know. Part of your problem could be the long 3 meter RCA interconnects you are using. You may have to try some that are 100% shielded. That can have a down side on the SQ of system. And even though the Furman P-2400 IT didn’t solve the problem and the signal noise is being radiated in the air, the power cords that feed your audio equipment will act as receiving antennas and pick up the signal and feed it into the audio equipment. As you probably already know a heavily shielded power cord can suck the air right out of the sound of an audio system. My experience with ferrite beads on a power cord can/does the same thing. Even the speaker cables can work as an antenna and send the noise to the speaker drivers. Just curious, by chance does you preamp have a headphone jack? If you have a pair of head phones it would be interesting to know if you can hear the noise through them. If you do have the jack and the phones and you still hear the signal noise though the phones disconnect the RCA interconnects from the preamp that feed the amp/s. Are these interconnects the 3 meter long ones? Jim |
I found this: http://blog.rfvenue.com/2015/05/06/how-to-prevent-cell-phones-from-interfering-with-audio-equipment It talks about cell phone noise in a pro audio setting, and mostly with phones as the source of the noise, not a cell tower. But they do mention a way to get rid of the noise that hasn't been mentioned yet. It wouldn't be the best fix, but could at least let you see if it's coming through the RCA cables. Their fix: ferrite beads on the input cables, close to the end that plugs into the amp. The article recommends specific ferrite parameters to address cell phone noise.. If ferrites on your IC cables solve the problem, you could look at more heavily shielded ICs. If not, you're only out the cost of ferrites.. |
