Chao Chipp Posted January 11, 2021 Share Posted January 11, 2021 Got an interesting hum and buzz coming from my turntable and I believe it is a ground loop issue. So my question is how I could make the buzz more bearable? My old turntable is quiet but the new one is noisy like fly, especially when I turn the volume knob to 1 o'clock on the preamp. Have asked the seller to change to a new toneamp and went for a new set of cable, interconnection cable and still the same issue. The turntable has two arms. The other arm is noisier and both two use the same ground cable connecting to the phono stage. Would this is the issue? What option should I explore here? Link to comment Share on other sites More sharing options...
andyr Posted January 11, 2021 Share Posted January 11, 2021 That's no good, Chao. If your old TT was quiet then it's obviously just a (bad! ) problem with your new TT. It would probably help people if you told us: what your old TT was and what your new TT is. Andy Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 11, 2021 Author Share Posted January 11, 2021 My old one is the http://www.opera-consonance.com/products/analog/Isolde.htm and the new one is http://www.opera-consonance.com/products/analog/DieLP.htm The hum, buzz noise is somewhat bearable but I still want to reduce it. On some quiet tracks, it is noticeable. Link to comment Share on other sites More sharing options...
aussievintage Posted January 11, 2021 Share Posted January 11, 2021 1 hour ago, Chao said: The turntable has two arms. The other arm is noisier and both two use the same ground cable connecting to the phono stage. Would this is the issue? What option should I explore here? Is is very likely a grounding issue, yes. However, diagnosing these problems is often a matter of trying the possible combinations. - tonearms, with and without ground - one tonearm with and one without, and the other way around - turntable with and without ground - tonearms isolated from turntable, or grounded to turntable, and with or without ground - all grounded to phono preamp, or to main preamp or power amp, or not - etc etc Link to comment Share on other sites More sharing options...
andyr Posted January 11, 2021 Share Posted January 11, 2021 2 hours ago, Chao said: The hum, buzz noise is somewhat bearable but I still want to reduce it. On some quiet tracks, it is noticeable. You should not have to put up with any such noise! 2 hours ago, Chao said: My old one is the http://www.opera-consonance.com/products/analog/Isolde.htm and the new one is http://www.opera-consonance.com/products/analog/DieLP.htm These are both good TTs - you shouldn't have the problem you do. Can you return it to the dealer and/or get them to fix the problem? Andy Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 11, 2021 Author Share Posted January 11, 2021 Well, i'm still in 'honeymoon' and talking to the seller everyday. He also has some ideas about this but as we are a bit far away to each others, it would be hard to troubleshooting these. My system and his are completely different and it only happens on mine. It could be too near the wall, too near the power socket, etc. But if it is the case, my old one would have the same issue too. Is it a good idea to take the turntable off and clean it??? Would it be the issue with the grounding cable as two arms linked to each other cause the issue? Or I need to get an isolate transformer, a cheat plug? Link to comment Share on other sites More sharing options...
Doppelganger Posted January 12, 2021 Share Posted January 12, 2021 Can you take a picture of the tonearms that shows how this shared grounding is set up? Ordinarily, each tonearm would have its own grounding scheme. 1 Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 12, 2021 Author Share Posted January 12, 2021 Well, the two tonearms earthing cables are linked together in the middle. From then, a single cable is run to the ground cap on the phono preamp. Its like an Y crossroad. Link to comment Share on other sites More sharing options...
Scott Piesse Posted January 12, 2021 Share Posted January 12, 2021 (edited) 1 hour ago, Chao said: Well, the two tonearms earthing cables are linked together in the middle. From then, a single cable is run to the ground cap on the phono preamp. Its like an Y crossroad. If I were you Id listen and follow @Doppelganger's advice. Its probable most others (with the best of intentions) are guessing... doppelganger has experience beyond belief... If you choose to listen to anyone listen to him. Thats the only thing I could add here.... Listen to a true expert. Edited January 12, 2021 by ScottyPeace Link to comment Share on other sites More sharing options...
Doppelganger Posted January 12, 2021 Share Posted January 12, 2021 7 hours ago, ScottyPeace said: If I were you Id listen and follow @Doppelganger's advice. Its probable most others (with the best of intentions) are guessing... doppelganger has experience beyond belief... If you choose to listen to anyone listen to him. Thats the only thing I could add here.... Listen to a true expert. Thanks Scott but I don’t consider myself an expert! Certainly I’ve had experience with many turntable set ups but no more (and likely less) than many others here. The thing with turntable hum is that it can be down to a multitude of reasons and guesswork and trial and error are the key to resolving it - eliminate one potential cause at a time. The reason the two tonearms sharing a common ground wire intrigues me is that essentially doubles the possibility that the cause is related to this grounding scheme. Testing would require taking one tonearm and cartridge out of the equation at a time and seeing if removal from the system kills off the hum. Not sure if this is possible as I can’t picture the grounding scheme for two arms sharing a ground wire. A picture would be very helpful. 2 Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 13, 2021 Author Share Posted January 13, 2021 Had a chance to take some pictures of the ground setup. @Doppelganger. The other tonearm has a cartridge setup there but didn't connect to any cables at all. In the end, I have tried: - Move the turntable - Change powerboard - Replace cables - Move grounding setup further away from turntable and amp The interesting thing is my old turntable doesn't have hum like this, and it only has 1 tonearm which made me and the seller believed something might be wrong with the other arm or the grounding system too. Link to comment Share on other sites More sharing options...
Colin Rutter Posted January 13, 2021 Share Posted January 13, 2021 I would isolate one if the tone arms fron the TT and the preamp (nothing connected anywhere). Fire up the other arm, hear what happens? If hum. remove or install ground wire from arm to preamp. Did anything change? If not leave the earth in disconnected. If there was change leave it in the quiet position. If hum is still there, pull out the leads from the TT and short the terminals this should eliminate all hum. If not its not in the TT. If hum is gone replace one of the leads. Hear what happens. Remove and replace other lead, hear what happens. Then report back 1 Link to comment Share on other sites More sharing options...
Doppelganger Posted January 13, 2021 Share Posted January 13, 2021 Agree with Colin - you need to test each tonearm individually to ascertain which, if either may be causing the issue. Link to comment Share on other sites More sharing options...
aussievintage Posted January 13, 2021 Share Posted January 13, 2021 51 minutes ago, Doppelganger said: Agree with Colin - you need to test each tonearm individually to ascertain which, if either may be causing the issue. I did suggest this a while back 1 Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 13, 2021 Author Share Posted January 13, 2021 Well, I did try every suggestion and the hum is still there. I'm not really a techie person on TT so that is the reason im asking here. The hum definitely comes from the TT. The TT has 2 tonearm, one old and one brand new. The brand new tonearm has less hum than the old one. I don't use the old tonearm so I just leave one cartridge over there, doesn't hook in any interconnect cables on that arm at all. Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 13, 2021 Author Share Posted January 13, 2021 Here is the noise, sound like 120hz for me. https://imgur.com/a/d6i4ndq If i touch the tonearm, there are some statics. Link to comment Share on other sites More sharing options...
Scott Piesse Posted January 13, 2021 Share Posted January 13, 2021 (edited) 14 hours ago, Doppelganger said: Thanks Scott but I don’t consider myself an expert! Certainly I’ve had experience with many turntable set ups but no more (and likely less) than many others here. The thing with turntable hum is that it can be down to a multitude of reasons and guesswork and trial and error are the key to resolving it - eliminate one potential cause at a time. The reason the two tonearms sharing a common ground wire intrigues me is that essentially doubles the possibility that the cause is related to this grounding scheme. Testing would require taking one tonearm and cartridge out of the equation at a time and seeing if removal from the system kills off the hum. Not sure if this is possible as I can’t picture the grounding scheme for two arms sharing a ground wire. A picture would be very helpful. Hi Greg :-)) I didnt necessarily mean to make you out the total expert on this mate ;-)) I just know a couple of things about you... First... you wont say anything on a subject if you dont have something helpful or insightful to say... and therefore... Second... if you do actually say something its worth listening to Edited January 13, 2021 by ScottyPeace 1 Link to comment Share on other sites More sharing options...
Colin Rutter Posted January 13, 2021 Share Posted January 13, 2021 12 hours ago, Chao said: Here is the noise, sound like 120hz for me. https://imgur.com/a/d6i4ndq If i touch the tonearm, there are some statics. That would be 100hz Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 14, 2021 Author Share Posted January 14, 2021 Alright, @Colin Rutter had kindly come over and had a look at my TT. It turned out there was a shielding issue/problem at the tonearm wire picking up noise from somewhere. I need to get the tonearm fixed or looked at Link to comment Share on other sites More sharing options...
andyr Posted January 14, 2021 Share Posted January 14, 2021 (edited) 11 minutes ago, Chao said: Alright, @Colin Rutter had kindly come over and had a look at my TT. 11 minutes ago, Chao said: It turned out there was a shielding issue/problem at the tonearm wire picking up noise from somewhere. I need to get the tonearm fixed or looked at What tonearm is it? And does it have a plug somewhere (like at the base of the pillar - which a phono cable plugs into) ... or is it continuous wire from headshell ... through the arm and then to the phono stage? Andy Edited January 14, 2021 by andyr Link to comment Share on other sites More sharing options...
Colin Rutter Posted January 14, 2021 Share Posted January 14, 2021 The second pic reveals the tonearm wires. They just poke out near the rear of the wand and go into a black terminal block. You can see the rcas in the pic. If you touch the wires or move them the hum alters. It really only super annoying at loudish levels. But still shouldn't be there. Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 14, 2021 Author Share Posted January 14, 2021 @Colin Rutter Thanks for today. I just did a litter test and it seems the tonearm is not entirely the issue. If I unhook the serial cable from the TT, the hum just gone. If I hook the serial cable in, it is back. This happens no matter where I put the power brick. You can see the image Link to comment Share on other sites More sharing options...
Colin Rutter Posted January 14, 2021 Share Posted January 14, 2021 That would explain why the hum increased when we turned that off. What is that box doing? Your getting closer. Link to comment Share on other sites More sharing options...
Chao Chipp Posted January 14, 2021 Author Share Posted January 14, 2021 That box powers the turntable moving. I suspect the serial cable or the socket is the culprit here. Or the actual motor inside the turntable. The cartridge doesnt pick up noise from the box. Only when the serial cable connected to the TT to power the TT up, it picks up. Even if I leave the switch off, it still there. Link to comment Share on other sites More sharing options...
aussievintage Posted January 14, 2021 Share Posted January 14, 2021 12 minutes ago, Chao said: That box powers the turntable moving. I suspect the serial cable or the socket is the culprit here. Or the actual motor inside the turntable. The cartridge doesnt pick up noise from the box. Only when the serial cable connected to the TT to power the TT up, it picks up. Even if I leave the switch off, it still there. The serial interface includes a ground. You have found your ground loop. Now, how to solve it? What about grounding your tonearms to the metal box that the serial cable comes from? Link to comment Share on other sites More sharing options...
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