@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?
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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- 33 posts total
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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@lewm I know he doesn’t have hum. But a cartridge susceptible to hum may also be sensitive to RF breakthrough.
Because he said the turntable in another room is fine. i.e. not affected by the antenna.
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All, I wanted to close this discussion out with a long awaited almost resolve to the issue. I tried 2 other turntables in the system and the noise from the 5G tower was virtually non-existant. I did buy some Faraday fabric and after finding the hot spot pinned it to the wall which dropped the noise significantly further but the issue with the VPI Scout was still in full bloom every time I plugged the RCA's into the back of the table! I even tried covering the TT with the Faraday cloth and it still came through. The only difference between all the tables I plugged in was the cartridge set up. All the other were MM and the VPI was fitted with a Low Output Grado. I flipped the switch on the back of the phono preamp to MM and the noise dropped immediately to almost silence. I removed the LOMM cartridge and installed a High Output Grado Ref 3 MM and all is good. Not 100% great I can still hear faint 5G data transmission between tracks but not enough for me to fight with it anymore. Thank you all for jumping in to try and help me out! K |
Sorry OP, I know how frustrating analog issues can be. When I had an Audio Research Reference 3SE Phono, I found its High Gain mode highly susceptible to noise from my plasma TV an adjacent room. It sounded like demonic gargling noises (lol). Other MC phono stages, like Herron VTPH2A, were not susceptible to this noise. Using the Ref 3SE in Low Gain more with a SUT was completely immune to the noise. Interestingly, the Ref 3SE has an acrylic top - to show off the nice insides. It looks like your Black Ice Fusion F159 also has a non-metal glass or acrylic faceplate? Perhaps that’s related to this issue. By contrast, SUTs are generally extremely well shielded. Grados are also known to be poorly shielded. I suppose the noise can inject itself anywhere there’s a weak spot in the chain, and the lower the signal level at its injection point (cart, tonearm, MC stage), the worse it manifests. Anyways, high chance that MC stage is contributing (faceplate). Then on your JD9 - I always wondered about that unit’s specs - they seem to be impossible, or frankly made up, but nobody seems to question it. 70dB gain MM mode, 95dB MC mode, 100dB signal-noise? That’s literally impossible. I wonder what is the actual gain on these units? If the spec were true, you’d never need to run MC mode except for something like a 0.05mV Ortofon MC2000. |
- 33 posts total