Hi everyone. Tom your idea about balanced power across the hot and neutral is fantastic. Since more and more devices are coming with external power sources, the potential for noise in your audio system is increasing.
I have come across a balanced transformer designed for pro audio in mind, its also comes in a rack mount version. http://www.equitech.com/products/rack/modelq.html
Jeff
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From: "Tom Graefe" Date: Tue, 30 Jun 2009 19:52:47 -0400 To: <sony-mxp-3k@yahoogroups.com> Subject: Re: [sony-mxp-3k] Monitor Hum
Congrats Dave! Now maybe try Balanced power. 60V on neutral and hot, centertap to ground.. Eliminates a lot of stuff. That is why I love the power in Europe. Balanced power. For the USA try a 240 V to 120V center tapped transformer. Plitron.
I got it! Thanks everyone! It was the breakers. They were all over the place. I put them all on the same pole (every other breaker). turned the console on, and the noise disappeared. Even my direct box noise is gone! It just makes the noise when the console is off now, and I can't use it with it off!
Thanks everyone, Dave
To: sony-mxp-3k@yahoogroups.com From: graefe@gate.net Date: Tue, 30 Jun 2009 17:08:51 -0400 Subject: RE: [sony-mxp-3k] Monitor Hum
OK, now disconnect the other alternate speakers you did not mention before. The speaker selector is the key here.
Tom
-----Original Message----- From: david odell Sent: Jun 29, 2009 9:51 PM To: Sony users group Subject: RE: [sony-mxp-3k] Monitor Hum
When he installed the breakers he did do that, but I had someone else upgrade the panel and he switched them! I will change them around but,
I don't think this will make a difference Because I get the noise even if all the consoles supplies are unplugged from the outlets!!
The noise only disappears if the monitor inputs or monitor module is disconnected from the speakers. Also it disappears if I switch the speaker selector off, this is all done with the console off, and unplugged from the outlets. It makes the noise regardless if it's on or off, plugged in or not!?!?
Thanks, Dave
To: sony-mxp-3k@yahoogroups.com From: graefe@gate.net Date: Mon, 29 Jun 2009 17:48:24 -0400 Subject: Re: [sony-mxp-3k] Monitor Hum
David,
Is there a measurable voltage difference between the Pin one input of the Events and the Pin 1 from the XLR coming from the console? I know your Drummer is a licensed Electrician but, did he put your console and all the outboard gear on the same 120 V phase? You said they have separate breakers, are those breakers on the same phase? Have you measured the voltage between Ground and Neutral on the outlets?
When you moved the console you didn't by any chance disconnect the power supply lines at the console end did you? Have you checked inside the Jones plug connectors on the power supply cables to make sure nothing has broken loose there? Jeff Chestek
david odell wrote: > > > Since moving I have been sorting out problems little by little. I am > getting hum on all monitoring devices(speakers and studio outs). With > the monitors plugged in and switched on, by them selves there is no > noise, but as soon as I plug the speaker tuchel in the the console the > hum is there, console on or off, also with the tuchel still plugged > in, if I remove the monitor module, the noise disappears. Is there > something wrong with the monitor module or a dreaded ground loop > somewheres? The hum shows on all the monitors and studio outs, not the > 2-mix, line in/outs, or anything else. I also get a wicked hum when > plugging in my direct box too. It never hummed in the last place it > was at. What should I do?? > > Thanks in advance, Dave > > ---------------------------------------------------------- > Insert movie times and more without leaving Hotmail®. See how. > <http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tutorial_QuickAdd_062009> > > >
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Since moving I have been sorting out problems little by little. I am getting hum on all monitoring devices(speakers and studio outs). With the monitors plugged...
I hate grounding issues! Is it a noticeable hum, or do you have to stick your ear up to the monitor(s) to hear it? In my experience, a teeny bit of hum on the...
Hey, let me add that I'm not an expert at this stuff, and there are certainly more knowledgable perople in theis group. Nonetheless... One other thought, have...
It's a noticeable hum with the console on or off, volume up or down. I haven't tried the 3-2 plug but my headphone amp is a 2 prong and it has the same noise....
Well, then, the solution is obvious--move back to your old house!!! Cheers! p.s., c'mon experts on this board, help David out! ... From: david odell...
Dave, Chassis Ground Audio ground ground loop. Try lifting the Shields at the input. Also remove the power amps from the rack. Then Isolate them. Are they...
The monitors are powered event monitors. To: sony-mxp-3k@yahoogroups.com From: graefe@... Date: Sat, 27 Jun 2009 17:26:10 -0400 Subject: Re: [sony-mxp-3k]...
Tried to lift the ground on the monitor input wires and it's still there. Is it possible it's the console? The monitors are noise free till they connect to the...
Dave, It is possible the monitor module is dead? Does it put out a signal on both the hot and low legs? Have you tried lifting the Shield yet on the XLR that...
Not that I know of? I'm not sure what you mean? I get sound out of it. How do I check if signal is on both legs? I disconnected the shield on pin 1 and that...
Now that is strange? The monitors must be on a different 120 volt phase from the console? Try running an extension cord from the outlet that the console is...
Hi, my first thought is the same as Tom's. With the monitors being on a different phase than the console. I have also seen poorly made transformers send a...
I already tried an extension cord a while back and that didn't solve anything. My drummer is a licensed electrician, He ran all the wire new. nothing is...
When you moved the console you didn't by any chance disconnect the power supply lines at the console end did you? Have you checked inside the Jones plug...
I left the connectors intact at the console end. I will check the plugs to see. Thanks Jeff, Dave To: sony-mxp-3k@yahoogroups.com From: jchestek@... ...
David, Is there a measurable voltage difference between the Pin one input of the Events and the Pin 1 from the XLR coming from the console? I know your...
When he installed the breakers he did do that, but I had someone else upgrade the panel and he switched them! I will change them around but, I don't think this...
Have you tried disconnecting EVERYTHING from the console except the monitors? Pull ALL the tuchels except for the monitor output (and make sure nothing is...
Thanks Jeff, Didn't try that one! I will try it when I get home and report back. Thanks, Dave To: sony-mxp-3k@yahoogroups.com From: jchestek@... Date:...
Use a scope to see if there is a signal on Pin 2 and an inverted signal of the same amplitude on pin 3 of the XLR going to the events. Use the console...
OK, now disconnect the other alternate speakers you did not mention before. The speaker selector is the key here. Tom ... When he installed the breakers he did...
I got it! Thanks everyone! It was the breakers. They were all over the place. I put them all on the same pole (every other breaker). turned the console on, and...
With the console OFF you can get all kind of weirdness, but The speaker selector hooks the Hi and Low side of the NOT selected speakers to Audio ground to mute...
Congrats Dave! Now maybe try Balanced power. 60V on neutral and hot, centertap to ground.. Eliminates a lot of stuff. That is why I love the power in...
Hi everyone. Tom your idea about balanced power across the hot and neutral is fantastic. Since more and more devices are coming with external power sources,...
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