He doesn’t have “hum”, in the sense of 60 or 120Hz noise. He needs shielding from that nearby radio antenna, and yes, the shield must be grounded to have an effect. We don’t know whether even his cables are shielded. Seems to me the only thing to be gained by selectively breaking existing ground connections is the possible introduction of hum, which is not a gain.
Phono cartridge noises
Hi All,
I finally after many years built a new home with a dedicated music room and was quite happy with it until I connected my turntables. I've never run across this and looking for advice as I'm truly lost on what I’m experiencing.
I have two phono preamps, the Jolida JD-9 II / Grado Gold G2+2 High Output cartridge / Project RM 1.3 and a Black Ice Fusion F159 / Grado Reference Low Output cartridge / VPI Scout. Without the cartridges connected I have a slight bit of air noise when I turn up the volume which I kind of expect. As soon as I plug in the cartridges I pick up what I think is internet noise and not in a small way. The high output masks it to a point, the low output can't be used at all. It sounds like I'm on a spaceship! It's a high pitched noise with a morse code like beeping sound, a lot of background kinda rumble/flutter and distortion. The room is wired for ethernet but as yet not connected I only have WiFi in use. When I switch to any other source input on the main preamp all noise goes to silence. I have connected the phonos with different cables from Transparent Audio, Morrow, Original phono cables that came with the tables and even tried an old set of Monster Cables; all produce the same result as soon as the cartridge is introduced into the loop.
Has anyone come across this I'm truly stumped?
K
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- 28 posts total
@lewm It's basically adding a signal at any point in a circuit for whatever reason, mainly troubleshooting. See here for more info. In this case the added signal is the unwanted RF. |
All, Thank you all for trying to assist, I'm going to answer everyone I hope!
Lewm - You are correct I do not have a 60/120Hz noise. I have a very high pitched tone with morse code type noise and a low pitched like rumble going on - the subs don't like it!
mijostyn - I have disconnected everything with the exception of the phono preamps/preamp and mono blocks. I did use ground lifters on all with no change; the RF noise is very much present. As I said to Lewm above I don't have a hum I have what sounds like internet traffic. noromance - I'm not sure how the tracer would help the noise doesn't appear until the cartridge is adde to the loop. I'm noise free all the way to the turntables themselves. As soon as I plug the cables to the table(s) the noise is immediate. I have tried both shielded mid-line Transparent Audio Phono cables, Morrow PH-4's, and even an old pair of Monster cables all with the same result. silence until the tables are plugged in. I tried cupping my hands around the cartridge with no change. What the heck it could hurt! History: the system did not have any of these issues at my old house. The only changes to it were the addition of the Black Ice Phono preamp; an existing Jolida JD-9 (has the noise as well) so it's not the Black Ice, new speakers, new home with a dedicated media room. As an 'I know this shouldn't change anything but' last night I moved the two 100+ pound new speakers out of the room and replaced them with my old B&W's - other than wearing me out there was no change as I figured but anything is possible and needs to be ruled out. This weekend I'm going to move one of the TT and preamps to my den which is in the middle of the house on the second floor across from the media room. In that room I have an McIntosh integrated with an Project TT fitted with an Audio Technica MM cartridge. This system is not picking up the noise which is truly a mystery. If it is the tower it should be present in that room as well. The media room does have LED lights/no dimmers that are on a different circuit. Noise doesn't change with them on or off. I have a whole house Surge Protector again, no difference if it's on or off. There are 3 dedicated circuits pulled to the room that run under the floor to the outlets behind the system. One is for the Mono blocks, One for the home theater amp (not yet installed) and the third powers the outlets around the room to handle the subwoofers. The only thing in the ceiling are the 2 A/C vents. Two walls are brick and two are cement panels; one contains the window 36"x36" in the rear side looking at the 5G tower. Not sure if any of this helps just providing background in case it triggers something. Again, THANK YOU ALL for sharing your knowledge to help me solve this. K I'll report back once I move the TT tot he den. |
@skyy75234 Yeah, the tracer was between me and Lew in discussing signal injection. Are you sure there are no routers/modems/repeaters near the room? Grados can be prone to hum. Have you tried a different cartridge? |
He doesn’t have hum. He just said so. Although it’s a good idea to worry about routers/modem/repeaters, why go there when we know he has a giant radio antenna 1000 yards from his room? In medicine there is a canard about hearing hoofbeats and worrying that you are about to be trampled by zebras. Skyy, you last wrote, "As soon as I plug the cables to the table(s) the noise is immediate..." This makes me envision the cable from your tonearm into the phono stage. Is that correct? This means the RFI is getting in anywhere from the connector input to the phono stage to the cartridge itself. Have I got that right? And you say your phono cables are shielded. Correct? Just to prove the source, I wonder whether you could put together a cage made out of metal wire fencing or screen (smallest holes practical) and place it over your turntable, completely enclosing it. (Ideally, you'd want the cage to have a bottom as well, running underneath the TT.) If that affects the problem positively, that would at least tell you what to target with some more practical shield. Faraday cages need to be grounded, too. You could ground that contraption to the wall socket ground.
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- 28 posts total