After my electrician ensured that all the three dedicated lines where correctly installed with same phase, and added a dedicated ground rod to just these three circuits, there was around a 75% improvement in noise reduction, but it was still there.
It was only after that I moved all my 'wall wart' power supplies from my three WD portable hard drives, my computer power supply, and Universal remote power supply on its own power strip off a plug being used by 'general room' power, and placed into a second Equitech unit, did my hum completely go away. I was only using one PS Audio P-5 as a conditioner, and I did not have enough plugs to have my entire rig powered by the 3 dedicated 20 amp lines. That has always been one of the tips from the Forums to help eliminate hum and unwanted ground potential differences. I did not appreciate how significant that simple tip would be, nor realize what was necessary to achieve that goal, but I'm glad that going back to basics, and following all the tips produced my desired result.
... After my electrician ensured that all the three dedicated lines where correctly installed with same phase, and added a dedicated ground rod to just these three circuits, there was around a 75% improvement in noise reduction, but it was still there.Are you saying that these ground rods are not bonded to the neutral/ground in your main service panel? If so, that's a definite violation of the NEC and potentially dangerous. This is an example of why one should always obtain proper construction permits for work such as this, and then follow-up with an inspection by your code official.
I too installed 3 dedicated lines (by myself). And I also did not put one on the same phase. It’s easy to do since you think you should keep them close together in the breaker box. I eventually did move the oddball to the same phase.
Another BIG offender is cable / sat rca connections somewhere in the audio system. I used a ISO-Max and that eliminated that problem.
I am now using a tube amp and everything, including ground noise, hiss etc.is dead silent!
I’m also not sure about you using an additional grounding rod. Can you try it without using a separate grounding point?
thanks for folks for reading this post, and offering appropriate comments.
Cleeds: here is comment from my electrician:
"Regarding the question about being bonded to the main panel ground, yes the new grounding system is also bonded to the main panel, all grounds tied together. So glad to hear that it is working perfectly now "
Ozzy: I was able to listen to my system after all three lines moved to same phase, and prior to new ground rod installed. The ground rod only added a small, but perceptible improvement in hum reduction. I do have a Directv box, which is now plugged into Equitech, as is my Marantz, which only has a two prong power cord...my hunch was that the combo of Directv and Marantz contributed to the hum, and now also using balanced power helps in addition to my other efforts. When I tried to use in line filters on my Directv, it failed to send any video data thru...I think they work best on cable TV systems, not satellite systems, but I am not aware of how your specific solution of ISO-Max works for Directv.
Glad we are now both in the 'hum free' zone.
I hate hum, put "noiseless" pickups in guitars where needed, spend lots of time locating and removing hum from live concert rigs, and will not tolerate even a spec of hum in my hifi pile. However, I have dimmers all over the place (love dimmers), no dedicated power lines anywhere, utilize an embarrassingly ancient "power conditioner" (ha) in my rig, and have zero hum coming from my humble stereo heap. Zero…I think I'm friggin' lucky…I did have some dimmer related hum in my turntable, but that went away when I replaced the tonearm (Akito) cable with a better shielded Mogami. Really lucky.
I gotta chime in here and say halleluya that you fixed your vexing problem. I have been plagued with it from time to time and finally have have sold gear to rid myself of the problem. There are a bunch of very sharp and helpful cats on this forum, you included, that are all about helping a guy sort out problems like you had. Yeah, hum is bad juju and I am delighted you got it resolved. Mark
Thank you, Bob! My listening room / living room is at the end of our house where ceiling access is either not available or very difficult. Can dedicated circuits be run *outside* the house to reach our room? If you don't mind my asking, what was the cost of adding 6 20-amp dedicated lines? I'm assuming I will need to replace our panel while we are at it, but I'd love to know at least a "ballpark" price for such work.
Maybe I can piggyback here.
I have an Oppo 95 connected to a PrimaLuna Dialogue Premium Integrated HP and Zu Druid. Druid are very sensitive and I had a pretty good hum going. Figured out that if I drop the ground from either the Oppo or the PrimaLuna the hum disappears. Both units are plugged into the same outlet. I plugged both into an Equitech balanced power transformer and figured that might work, but still the hum unless I drop the ground.
I'm a little uncomfortable running without the ground... especially with the Equitech given both power wires are hot.
Can anybody tell me what is going on?
I had three dedicated lines run from my breaker to the other side of a moderate sized home, which created 6 plugs ( 3 duplex outlets). The cost for a qualified electrician was around $5-600, this was a few years back, and I live in expensive SoCal...best to get an estimate, but be sure to have him read some of the forum posts about how critical it is to have them installed with all same phase...one of the best investments I did. Be sure your home ground is also adequate...consider adding a new ground rod, as long as its bonded and connected to main power ground.
Leotis: dropping the ground from the Oppo might not be so bad, as it doesn't draw a lot of power...even recognizing the potential risks of lifting the ground if that eliminates the hum. My two channel rig is now stone quiet with the above modifications, but when I engage my Home theater aspect in an integrated fashion to my 2 channel, I do still have a less annoying but still present hum....it might be my Oppo 105, Directv, or Marantz 8802. Also to achieve balance audio sound levels, I need to have my Veloce pre for HT bypass set at a pretty high sound output level, the hum increases with the volume output of the preamp. I will try to eliminate that bit when I have more time.