Members ElectricPuppy Posted October 9, 2007 Members Share Posted October 9, 2007 Sunday I finally got some of my gear back in order. I've retired my Behringer mixer and plan to use my FireStudio and Sonar instead. I had to make space in my rack, though, so I pulled everything out, untangled all the cables, put everything and the FireStudio back in, plugged everything in (screwed-up the MIDI, doh, redo), and spent about 1/2 hour figuring out how to get Sonar to hear the FireStudio (there was no playback master clock selected by default for some dumbass reason). Anyway: I get it all working, slap on my handphones, and what do I hear? HUMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM Sonofabitch. So, Now I get to pull everything apart again, one-by-one, until I find the source of the ground loop. All I really want to do is play, why won't my gear cooperate? The puzzling part is that I have everything (and I mean EVERYTHING) plugged into a single outlet in my room to avoid groundloops through multiple outlets (a common problem). Grrr. Anyone else have ground loop problems? What was the cause? /rant Link to comment Share on other sites More sharing options...
Members carbon111 Posted October 9, 2007 Members Share Posted October 9, 2007 Make sure the computer is on the same circuit all of the other gear is - sometimes a ground loop is formed through the USB audio interface. I had the hum issue and fixed it by plugging the computer into the same side of the room everything else was. Additionally some gear that has plugs with no ground lug - the plug can be unplugged then rotated 180deg and plugged back in - sometimes that will quiet down a hummer. Whatever you do, don't lift the ground on any gear! Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 9, 2007 Author Members Share Posted October 9, 2007 When I say everything, I mean everything, including the computer, all get their power ultimately from The One Plug. I did have that problem before when the printer was plugged into a separate outlet, and the USB cable did indeed cause a loop, but that's no longer the case. I will never, ever lift a ground. Sound advice. I'll check the 180-turn of the plgus, though. I think most of those are transformers, though, so it shouldn't make a difference, but... you know. I'm frequently wrong. Link to comment Share on other sites More sharing options...
Members drxcm Posted October 9, 2007 Members Share Posted October 9, 2007 The 180 turn thing should make no difference to AC currents from a theoretical point of view, but some degree of mysticism is always present with these kinda things. Just out of interest why will you 'never, ever lift a ground'? I've star-grounded my setup and most gear has been ground-lifted. Prior to doing so I had hums all over the place, now it is silent. Link to comment Share on other sites More sharing options...
Members drxcm Posted October 9, 2007 Members Share Posted October 9, 2007 Re: ground lifts Of course I meant AUDIO grounds.I would never lift a power ground. Link to comment Share on other sites More sharing options...
Members Numina Posted October 9, 2007 Members Share Posted October 9, 2007 On several occassions, I've traced a ground loop to the rack screws making contact with both the rack and the module. You may need to loosen some of your rack mount gear until you hear changes in the hum. I've also had the same issue with rack gear touching adjacent rack gear. Weird, I know but check those out. I bought some rack screw isolators and tried to make gaps bewteen the modules and this helped. Every once in awhile it comes back but it's always the same cause. For example, my Waldorf uQ was the source of a buzz and as I loosened the screws the buzz went away. In another case I had a TR-Rack in slight contact with a MUTO 828mkII and once I made a gap and used isolators it went away. Let us know how it works out. J. Link to comment Share on other sites More sharing options...
Members OPEN OCEAN Posted October 9, 2007 Members Share Posted October 9, 2007 always the same hehe.... Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 9, 2007 Author Members Share Posted October 9, 2007 Drxcm: Yes, I meant power grounds. Don't lift those. I'll consider the audio ground lift if I can't find the source, though. First I'm going to plug in an isolated audio source into the FireStudio (like a battery-powered CD player) and see if the hum's still present, that would at least narrow it down. Numina: Good idea, I'll try that, thanks. Link to comment Share on other sites More sharing options...
Members carbon111 Posted October 9, 2007 Members Share Posted October 9, 2007 The 180 turn thing should make no difference to AC currents from a theoretical point of view, but some degree of mysticism is always present with these kinda things. I heartily agree as I have a good grounding in electronics. However, for non-polarized AC gear, I've had this solve hum problems in the past. Honestly, its not just me being superstitious or stupid...I could bring the hum back just by rotating the plug again. Link to comment Share on other sites More sharing options...
Members drxcm Posted October 9, 2007 Members Share Posted October 9, 2007 ^ Hopefully I wasn't inferring stupidity, it certainly wasn't intended Interesting though isn't it?! Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 9, 2007 Author Members Share Posted October 9, 2007 I heartily agree as I have a good grounding in electronics. nyuk nyuk nyuk Link to comment Share on other sites More sharing options...
Members carbon111 Posted October 9, 2007 Members Share Posted October 9, 2007 ...nobody likes a good (bad) pun any more. ...your capacitance for electrical puns may be low, but there's no need for such resistance! At least there wasn't a whole series of them but we can see its' parallel in other forms of humor. Shocking, isn't it? ...or maybe just revolting? Link to comment Share on other sites More sharing options...
Members pogo97 Posted October 9, 2007 Members Share Posted October 9, 2007 Watt? Link to comment Share on other sites More sharing options...
Members Gribs Posted October 9, 2007 Members Share Posted October 9, 2007 Hmmm... Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 9, 2007 Author Members Share Posted October 9, 2007 Thanks for your electrifying insight, Carbon. However, your circuitous puns cannot match the impedence of a truly overloaded pun. Perhaps if you had alternated between subtle puns instead of being so direct, you might have induced a stronger flow of humor. Instead, your current level of punnitry leaves us short. Good day, sir. Link to comment Share on other sites More sharing options...
Members carbon111 Posted October 9, 2007 Members Share Posted October 9, 2007 Link to comment Share on other sites More sharing options...
Members carbon111 Posted October 9, 2007 Members Share Posted October 9, 2007 Seriously, when you figure out what's causing it (the hum, not the bad puns), let us know. Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 18, 2007 Author Members Share Posted October 18, 2007 Found it. This fancy new PC we got recently has Windows Media Center on it, and Teh Wife wanted to use it as a second DVR to record some TV shows on it. Works great. To do this, though, I had to connect the cable to the PC, obviously. And hence, a ground loop was formed. When I disconnected the cable from the tuner on the PC... hum-be-gone! Evidently there's a real poor ground connection between the cable shield and the rest of the house. Oh well. I wonder if I can find some kind of cable isolation transformer...? Link to comment Share on other sites More sharing options...
Members Diametro Posted October 18, 2007 Members Share Posted October 18, 2007 Well that turned out to be a hum-dinger of a thread! Link to comment Share on other sites More sharing options...
Members Purity_Control Posted October 18, 2007 Members Share Posted October 18, 2007 ohm eye god! Link to comment Share on other sites More sharing options...
Members Meatball Fulton Posted October 18, 2007 Members Share Posted October 18, 2007 This fancy new PC we got recently has Windows Media Center on it Windows Media Center is the Antichrist Link to comment Share on other sites More sharing options...
Members Fuzzlabs Posted October 18, 2007 Members Share Posted October 18, 2007 And here I had hopes it would transformer itself into something of current interest Link to comment Share on other sites More sharing options...
Members ElectricPuppy Posted October 18, 2007 Author Members Share Posted October 18, 2007 And here I had hopes it would transformer itself into something of current interest Hey now... I'm trying to conduct a... um... bah, I've got nothin'. Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 18, 2007 Share Posted October 18, 2007 If I add my $.02 will resistance be met? Old tube equipment that utilized 2 prong ac plugs usually ran the neutral white wire to ground. Reversing the ac plug would energize the chassis with 120v. If this is done you will light up like this. Link to comment Share on other sites More sharing options...
Members Dejavoodoo Posted October 19, 2007 Members Share Posted October 19, 2007 Thanks for your electrifying insight, Carbon. However, your circuitous puns cannot match the impedence of a truly overloaded pun. Perhaps if you had alternated between subtle puns instead of being so direct, you might have induced a stronger flow of humor. Instead, your current level of punnitry leaves us short. Good day, sir. This thread is just running in cycles. Link to comment Share on other sites More sharing options...
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