collo Posted February 12, 2007 Share Posted February 12, 2007 Hi there, It's funny that one of the poster's suggested opening the sheath on the cable to the sub. I've got a writeup on using that method here: Minimising Hum Some overseas forums have laughed at the approach, but it might get you out of trouble, or at least help you locate the problem. In australia, if a peice of gear has an earth connection, it's there to protect you in the event of a fault that causes the case to become live. Disconnect the earth pin and you might not live to regret it! Bending earth pins or using "Cheater plugs" just aint worth the risk. You can use them as a diagnostic tool but that's all. regards Collo Link to comment Share on other sites More sharing options...
lehman05 Posted February 12, 2007 Author Share Posted February 12, 2007 By any chance does your sub have two RCA inputs but you are only feeding a single RCA into it leaving one RCA socket with nothing plugged in? There's 2 rca sockets, but one is sub in and the other is sub out, for if you want add in another one. Link to comment Share on other sites More sharing options...
Thornton Melon Posted February 12, 2007 Share Posted February 12, 2007 I don't have access to a step down transformer.I've tried the phase adjustment knob. I've unplugged every connection. I've tried hooking up the sub to a completely different circuit from the amp and also tried running the sub and the amp on a different circuit. The house is only about 4 year old so I'd like to think the wiring is ok. I've tried about 5 different rca cables all ranging in quality. As mentioned the sub worked fine at my old place. We did however move about 500k's and it's possible I suppose that a wire in the sub has come loose in the move. It was packed well but it might explain things. The other thing is the amp can be completely powerd off (unplugged from the wall) and as soon as I plug in the rca from the sub the sub hums. Can anyone say with any certainty that this could still indicate ground loop/faulty amp/faulty sub? The amp is a yamaha RX-N600B and the sub is an accusound. Why dont you ring ACCUSOUND and ask them,Ask for Alan Henning and I'm sure he will offer you some suggestions. He designed the sub. Cheers Link to comment Share on other sites More sharing options...
jokiin Posted February 12, 2007 Share Posted February 12, 2007 There's 2 rca sockets, but one is sub in and the other is sub out, for if you want add in another one. Ok, no problem there, does your amp have one or two RCA sockets for the sub output? Link to comment Share on other sites More sharing options...
hifi007 Posted February 12, 2007 Share Posted February 12, 2007 Bending earth pins or using "Cheater plugs" just aint worth the risk. You can use them as a diagnostic tool but that's all.regards Collo So what is the best and safest way to fix my problem? I agree its great to use as a diagnostic tool but thats all. Its a matter of finding the culprit by a process of elimination (both components and power sockets used). If you have some components on a different earth circuit it can change the result. It's funny that one of the poster's suggested opening the sheath on the cable to the sub. This method actually worked on my old Velodyne sub which had an earth. From my experience different subs are more or less sensitive to hum issues especially difficult to locate problems. Link to comment Share on other sites More sharing options...
lehman05 Posted February 12, 2007 Author Share Posted February 12, 2007 Ok, no problem there, does your amp have one or two RCA sockets for the sub output? The amp has just the one for sub out. Link to comment Share on other sites More sharing options...
jokiin Posted February 12, 2007 Share Posted February 12, 2007 The amp has just the one for sub out. Ok, have seen the same issue you have when it's one connector at one end and two at the other, obviously not related though as yours is not like this, worth asking just in case I thought Link to comment Share on other sites More sharing options...
norpus Posted February 12, 2007 Share Posted February 12, 2007 The amp has just the one for sub out. So lehman05, what of the suggestions above have you tried so far? Please summarise so we can reduce speculation and time and move forward with you, thanks Link to comment Share on other sites More sharing options...
lehman05 Posted February 13, 2007 Author Share Posted February 13, 2007 So lehman05, what of the suggestions above have you tried so far?Please summarise so we can reduce speculation and time and move forward with you, thanks I have been waiting to follow this up this morning and have just been speaking to a very helpful Australian manufacturer who will remain anonymous. The solution of trying a two pin plug obviously fixed things but would remain hazardous. The person I spoke said that it's a recognized problem in the industry when a consumer uses an Australian made sub with an imported amp. That is, that the sub would have the 3 pin plug consisting of the earth pin, however the imported amp might not. This will cause the hum. This manufacturer for the last few years makes up their own power leads. What they actually do is take a 3 pin lead and take out the 2 power wires leaving just the earth. This lead is then attached to the chassis of the amp and also plugged into 240v along with the 2 pin power lead from the amp. Hum fixed. They are sending me a lead. Hope I explained it correctly. Link to comment Share on other sites More sharing options...
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