View Full Version : [Help Needed] hum
leroyjr1
09-12-2008, 05:51 PM
Is a slight hum normal when using IC's. I am using signalII and notice a slight hum when I put my ear up to the speakers.
TouchOfEvil
09-12-2008, 05:57 PM
No hum on my setup. I had a hum when veiwing television but it was the IC's. Changed em out and byebye hum.
leroyjr1
09-12-2008, 06:11 PM
The IC's just arrived brand new from signal. Its not loud I have to put my ear directly onto the woofer to hear it 3 inches away it gone. Is that not a big deal or should I try to fix it.( different cables)
Any one else using Signal II noticed any hum?
Thanks
leroyjr1
09-12-2008, 07:58 PM
Anyone else running signal ic's?
Erik Tracy
09-12-2008, 08:18 PM
Is a slight hum normal when using IC's. I am using signalII and notice a slight hum when I put my ear up to the speakers.
You're picking up the sub-atomic magnetic interference being generated by the new Supercollider. :D
That you are picking this up as hum is a sure indicator that you have selected high quality ICs.
If you hook both ends of your ICs to an earth ground for 120 hours, then any latent sub-atomic magnetic interference should be dissipated.
Be sure to wrap them in tin foil during your burn-in to further shield them from more Supercollider radiation.... :p
olilugo
09-12-2008, 08:38 PM
I use signal IC II! no hum here. dead silent.
mmadden28
09-14-2008, 11:00 AM
Haven't had this issue yet (outside of a known source), but perhaps you have a Ground Loop issue. Search in this forum and I'm sure you'll find lots of suggestions for troubleshooting and resolving if it is indeed your issue.
Good Luck
leroyjr1
09-14-2008, 03:21 PM
I'm just going to leave it. Strange that you can move the IC's and it gets lower and louder. The way it is now I have to put my ear directly on the woofer to here it , and it doesn't increase when I turn the volume up. But i still know it's there.
MMADDEN28
Does you ONKYO 805 make any processing noise.
mmadden28
09-14-2008, 04:35 PM
Well, apparently I do have a hum, although very slight. It does not change with any volume changes either. I can't hear it unless I am right on top of the speaker. In the RTi12's I hear it in the mid section-nothing in the woofers, and a littel higher freq stuff in the tweeters. It's most evident on the CsiA6.
I suppose its possible I may have heard it before but dismissed it as the "noise floor". My seating is at least 14' away. The Cable box DVR is actually louder-so it hasn't caused me any concern-although now that you brought it to my attention, damn you-I'm sure it will eat away at me. :mad:;)
Anyway, I disconnected the IC from the input to the amp and the noise is gone. The output from the amp is absolutely dead quiet-so its not the amp causing it. It must be the Onk. Actually if I listen real close to the Onk I can hear its xformer hummimg-so its likely the cause (at least in my setup). Of course I am sure I have some AC wires crossing some of my ICs in the mix at several points due to the tight space its in. The next time I have all my gear out, I'll listen again to be sure its not AC interference.
I'd hook up the pre from my 2ch setup, but its already a known source of hum so it wouldn't be a good test. I'll see if I can find another source to connect to the amp in my HT rig to see if I still hear a hum.
FYI, my amp is plugged directly into the wall, and the rest of the equipment is connected to the PF60, the PF60 is then plugged into the same outlet as the amp (I'll be upgrading to some dedicated 20A outlets in the coming weeks).
leroyjr1
09-14-2008, 07:14 PM
try hooking a speaker up to your onkyo via speaker output terminals and see if you get a hum
mmadden28
09-15-2008, 01:56 AM
Can't do it right now-to tight-Next time I have it out I will.
leroyjr1
09-15-2008, 03:38 AM
the cable box dvr is actually louder-so it hasn't caused me any concern-although now that you brought it to my attention, damn you-i'm sure it will eat away at me. :mad:;)
hum huumm huuummm huuuummmm LOL
steveinaz
09-15-2008, 12:14 PM
You either have a ground loop, bad IC, or a near-by "noise-maker" inducing hum on that IC. Since moving the IC changes it's level, you could also have a loose jack on the back of your equipment...
Does a different IC remove the hum?
doctorcilantro
09-15-2008, 01:15 PM
Does a different IC remove the hum?
That's what I was wondering.
If your Onkyo is not a "3 prong" grounded device, you could try to reverse the AC polarity by flipping the plug around; my Sunfire pre allows me to do this because the plug is not made to fit only one way (e.g. like most a lamp).
Do you hear it on different sources via the Onkyo? Or have you moved one source to another input? What's the signal chain like?
DC (hi all...first post!)
leroyjr1
09-15-2008, 02:47 PM
No, changing IC's don't removed the hum. I think it has something to do with my Onkyo.Because when disconnect the ic's from the amp the hum is gone and when I hooked up the speaker via speaker wire terminal I still heard a slight hum. I am going to just leave it at the time because the room has to be dead silent and my ear has to be pressed up against the woofer in order for me to hear it. When I get some time I am going to send my Onkyo into Circuit City to get looked at. Thats what I bought the three year warranty for.
mmadden28
09-15-2008, 03:34 PM
That's what I was wondering.
If your Onkyo is not a "3 prong" grounded device, you could try to reverse the AC polarity by flipping the plug around; my Sunfire pre allows me to do this because the plug is not made to fit only one way (e.g. like most a lamp).
Do you hear it on different sources via the Onkyo? Or have you moved one source to another input? What's the signal chain like?
DC (hi all...first post!)
Welcome to Club Polk Doc. Are you a chef/cook?
doctorcilantro
09-15-2008, 07:14 PM
Yes, I do love to cook but not for a trade. Actually, as a father and grad. student I rarely have time. Lately, we've found a store which allows you to prep really good meals and freeze them for quick cook times. We're eating like kings lately and we both work! It's a great idea; I recommend it to any busy parent or professional.
xandra
09-15-2008, 08:52 PM
I had same problem (slight hiss from speakers) . till I got ground loop isolator. I've since also changed outlet to dedicated circuit. Now All is quiet on the eastern front.
In my case, noise appeared as soon as I added an Amp, and was caused by cable tv: Very easy to test... just unhook RF cable at point where it comes in wall.
steveinaz
09-16-2008, 01:49 PM
Yes, sometimes cable feeds that are grounded at a different potential (usually) can introduce some bad hum.
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