I want to start that I've read the FAQ's and guides and quite a bit of old threads on this forum but non of them resolved my issue. I will walk you trough the process which I went trough and try to be as detailed as I can. My reciever is JVC RX-5032V, hooked up to a pair of Harman/Kardon TS11 home theather audio system. I noticed a hum coming from my subwoofer, googled it and bunch of threads came up (most of which in this forum hehe) that pointed to the ground loop. Although we use 2 pin connectors in my country (and the ground loop seems to be an issue in countries using 3 pins) I started experimenting, plugging out different cables/changing the outlet/leaving only the subwoofer and amp plugged but none of it worked. I don't remember at which point (since all of this took me a good couple of hours to read all the info, go trough the manuals and etc.) I decide to turn up the volume - the hum does go louder with it and then I start noticing the same strange hum coming from my speakers as well. After quite a bit of experimenting the only thing left was my amp and two speakers plugged in. Here is how my amp looks from behind at the moment
. I still hear the humming noise from the speakers. Here are answers to some questions from another topic in the forum which seem pretty revelant:
Could try to isolate the cause. Is the noise the same as you change from one source to another (with all of them paused, of course)? Does the noise change when all the source units are powered off?
Yes the noise changes trough different channels. It is the same trough VCR/CD/TV but goes louder trough DVD. FM/AM channels are with the most noise. If I turn up the volume to maxium I can even hear the station I am tuned to (very low volume with distortions) although I don't have an antenna plugged in!
Does the AVR have some DSP modes operating, or room EQ? If so, does the noise remain the same as these are switched off?
It had, turning them off did lower the humming down.
Does the AVR offer an analog bypass option? Same noise there?
It does have an option for digital. Humming is different and a bit louder I think
Does the AVR include an FM tuner? Is it tuned to a station or just plays interstation noise when you select it? (Some AVRs leave the tuner on all the time so it can output to a second zone. If it is playing noise, maybe the crosstalk is becoming audible.)
It does. As I mentioned above the FM is audiable without an antenna when pumping up the volume.
And finally a very strange thing I noticed. Say I plug in my iPhone in the CD source and play some music . The CD source works as expected but if I change the source to say DVD and pump up the volume I can hear the music that is playing trough the CD source - very low volume with white noise. This goes for all other sources except the FM channel trough which I continiue to hear the radio station.
I have this theory that it all has to do with the FM since the volume of the hum is louder in the DVD source and as you see from the picture it is closer to the FM out. My guess is that my sources get intermingled and I hear low volume from all the other sources no matter which one is selected, and the hum is just the sound of the FM constantly on picking up some distrubances. However I am no music expert and I only reached to this conclusion trough pure trial and error - that's why I'm asking for your advice on what to do. I would love to not have to open the amp because I have never opened one before and I can't afford replacing it if something breaks but I am pretty confident with opening up my PC and other electronics so I will do it if very necesary.
If you have any further questions I would be happy to answer them. Thanks in advance for your help
PS: I forgot to mention the reason I'm sure it's not the speakers is because I tried different ones and they did the same thing.