no more hum

leftwinger57

I think you guys might remember that I was picking up a stray hum through or directly from my sub woofer. (Mantis) Dan suggested to try a double shielded RG-6 coax instead of the dedicated cable. I did and that hum was gone and I repositioned the sub in the room it should be in. I always thought the hum was from tying all ac wires together and that did nothing after undoing that.
Now I've always had this underlying hum which I thought was from running 30/40' double RCA cables to pick up I-NET radio in my bdrm where my computer is to my Yamaha 665 in the living room rack. I thought if it worked for the sub why not for the long RCA runs.
Parts/Express had a clearance sale on a siamese RG-6 coax and bought it w/ some female to to RCA male converter fittings. I did the run, ty-rapped it all, and mated the F-connectors to the other fittings. What a difference no hum, not even between songs. This was the cure I was looking for and it did not cost that much for this kind of piece of mind and the work was easy and I can't believe I let it go for this long. No joke double shielded coax works great for certain applications, it's not speaker cable but it sure proved it's worth here. Happy,happy joy,joy....

jeremymarcinko

Nice...glad it all worked out. Thanks for sharing the tip.

steveinaz

Good deal, ground loop hums can be a pain to troubleshoot.

leftwinger57

I'm not even sure it's a true ground loop hum. In the alarm business we called it a floating ground. Sometimes it was there and the meter would read wide open and then it would read a fully closed loop. A big contributor to this were squirrels who would eat the insulation, leave the bare wire which would touch a wet/ moist cinder block or insulation and viola a ground. That's only one example but they are a pain to hunt down. This time after thinking all was resolved some time ago now for sure it's gone and It was do to length of run, unshielded RCA cables running along side multiple cables all low voltage but many wires which can induce hum along this long route. Aagin thanks to Dan for the idea in the 1st place and after my 1st attempt failed I figured out what I did wrong and all is well w/ my tunes once again.

steveinaz

Good cable management can render a very "black" background. I seperate everything; analog from digital, IC's from speaker cables, and AC.

RamZet

Did you try a ground loop isolator first or a ground lift?

http://www.amazon.com/Philmore-Ground-Loop-Isolator-64-4005/dp/B004NWEHV4/ref=sr_1_10?ie=UTF8&qid=1447808043&sr=8-10&keywords=ground+loop+isolator

http://www.amazon.com/CableWholesale-Wholesale-Grounding-Converter-30W1-32200/dp/B000I96AUM/ref=sr_1_6?ie=UTF8&qid=1447808168&sr=8-6&keywords=ground+lift

leftwinger57

Thanks for the link I never heard of this device before but w/ the way it's set up I think it would be perfect .Only $8 and change it's worth it.