ejb14
Responses from ejb14
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm the EARs transformer is pretty noisy mechanically at your place; suggesting a power issue. The battery test was interesting and you would think would rule out dirty power, but that may have also just demonstrated the same power issue - hav... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm - I understand you are probably super frustrated by now - yes, you could go solid state, but the fact that the tubed units work fine elsewhere suggests the problem is not with your gear. I suggest that if testing the power for DC shows th... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm - my calculations might be incorrect, but the EAR amplifies a those low frequency signals (the mechanical transformer hum is a pretty low frequency I believe) something like 2500 times depending on how low the frequency. First an equaliza... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm if you are going to open up a wall socket to check things out, might as well check for DC voltage on your AC power too - just put your DMM to DC volts and the probes on hot and neutral - I don't think it would cause this issue as it typica... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm You could get an outlet tester from Amazon or a hardware store - one that would show open ground/earth would be important. Search Amazon for "outlet tester Prague" (or UK) - You can also use your DMM to test (google how to do it, lots of ... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @lewm - an excellent point - I was assuming the OP was on 50Hz AC power, based on one of his previous statements in this thread, and the circular plugs in the powerstrip in one of the pics he posted. @filipm - are you on 50Hz AC or 60Hz AC power?... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm I am not convinced you have a broken or poorly designed phono stage. Recap of the evidence so far: 1. You have a predominant 50hz hum in the noise as was analyzed previously. 2. Both the EAR and the ARC LS16 exhibit this noise in your ... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? I think your shorting plugs are doing their job, and you have verified that your input shields are properly connected to ground and that the problem lies elsewhere. Have you verified your power outlets (in the wall) have good ground? You can get ... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm (Perhaps) an easy test; take your DMM and with the Ear turned off, verify connectivity between the input RCA jack shields and the ground lug (not the case necessarily) or the output RCA jack shields. On my phono stages they are all conne... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm Hmm - perhaps I am missing something but the statement: "It still acts as a regular cable though, basically an antenna. " - I am not sure is correct once you connect signal to ground. I believe all the energy on the input should be drai... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? Ah - that is very telling. Of what, I am not certain, but it may suggest that your input RCAs are not connected (broken solder joint) to ground in their shields, or there is some other failure internally. If the shorting plugs are correct, it shou... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? @filipm "Is there a way to short the inputs without the input shorting plugs? (I have ordered them but it’s gonna take a while)." Just take a cheap RCA cable, cut off one end and twist the signal cable and the ground/shield wires together. Make... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? Just to be sure - sometimes "stopper" will not have a signal pin (like the AudiioQuest stopper is just an RCA cover with no center pin), but for this test you want shorting plugs with the center pin. You want the signal shorted to the ground so th... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? From all the tests you have done, and the results, I believe that your noise is RF interference entering through your inputs and being amplified by the Ear as though it were an audio signal. I suggest getting some shorting plugs (cheap on Amazon) ... | |
| Tube PHONO preamp interference - RFI, EMI, bad grounding? I believe I have heard something similar to this before - twice - but both were some time ago - the first time it was definitely a router. Turned off the router, problem went away. Someone near you may have a powerful router. That would explain wh... |