WaywardTraveller Posted March 27, 2006 Report Share Posted March 27, 2006 When I record with my RH10 using the AC adaptor I seem to get this loud EM hum that predominates on the recordings. As a result, I have to record using battery power (which works fine).Is there anything that can be done to get rid of the hum, or should I resign myself to using batteries whenever making recordings?peaceWaywardTraveller Quote Link to comment Share on other sites More sharing options...
dex Otaku Posted March 27, 2006 Report Share Posted March 27, 2006 I take it you're recording with a microphone.This problem results from the fact that the recorder itself has a floating ground. The power supply has no ground, and to make things worse, only unbalanced connections are used. Any mic that is powered by the unit will end up being biased with noise from the AC adapter. The same should not usually occur when recording with dynamic [unpowered] mics, self-powered [i.e. requiring a battery of their own] mics, or through the line-input.It is possible to leech the noise off by actually grounding either the unit or the mic canisters; touching any screws on the unit's case or, if you have a unit whose case is metal or part-metal, simply touching that part of the case may fix the problem. This is not usually a very practical solution.The only true solution is not to use the AC adapter for power when recording with a unit-powered microphone - so yes, you basically should resign yourself to using batteries. Quote Link to comment Share on other sites More sharing options...
WaywardTraveller Posted March 28, 2006 Author Report Share Posted March 28, 2006 I take it you're recording with a microphone.This problem results from the fact that the recorder itself has a floating ground. The power supply has no ground, and to make things worse, only unbalanced connections are used. Any mic that is powered by the unit will end up being biased with noise from the AC adapter. The same should not usually occur when recording with dynamic [unpowered] mics, self-powered [i.e. requiring a battery of their own] mics, or through the line-input.It is possible to leech the noise off by actually grounding either the unit or the mic canisters; touching any screws on the unit's case or, if you have a unit whose case is metal or part-metal, simply touching that part of the case may fix the problem. This is not usually a very practical solution.The only true solution is not to use the AC adapter for power when recording with a unit-powered microphone - so yes, you basically should resign yourself to using batteries.Yeah, I was using in-ear binaurals and a T-mic (the DS70P). And now that you mention it, I DID notice that a lot (but not all) of the noise went away when I touched my RH10 to move it while recording...your explanation makes perfect sense. Thanks for the helpful info. peaceWaywardTraveller Quote Link to comment Share on other sites More sharing options...
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