Amp and Subs Humming All of a Sudden

[jfray]

Where your cable line enters the house it is grounded....... Check to make sure the ground wire is tightly clamped to the ground rod and the wire is free of corrosion. This is usually the root of the issue.

[rjryan]

Thanks again, folks!

I'll give a closer look to the cable system and the ground wire coming into the house. The maddening issue remains that it is intermittent :-)

[W9TR]

Also try disconnecting the cable from ALL your set top boxes and see if the problem goes away. This also goes for the Internet modem/router if it is connected to the cable and eventually to your equipment.

Cable lines run on the same poles as power lines, sometimes for miles, and so large AC voltages can be induced on the outside of the cable. These voltages are proportional to the current being drawn on the whole AC power distribution feeder, so can vary dramatically based on time, temp, etc.

My cable read 90 VAC from the cable to house ground. The cable company came out immediately and fixed the grounding, but I still had 2 to 3 volts on the cable compared to the rest of my equipment. I had the cable company come back and put in an isolation device which fixed the problem for good.

Tom

[rjryan]

Thanks for all the thoughtful responses, folks.

It does appear to be the cable system. I went back and cleaned up the DIRECTV installation as it was a bit of a rats nest, and that lessened the issue noticeably.

As for cable, it is only running the internet, but, is connected to a 24 port switch that is connected to a few of my components. I will be diving into that today, although, the component connected to the subs via the .1 input on the REL (Marantz 8802) is connected to the network wirelessly for just this reason. Still hunting!!

[rjryan]

Problem(s) sort of solved.
DIRECTV dish not grounded at all. Once I grounded the splitter inside to my Shunyata, the noise decreased exponentially. Still not dead silent, but your have to have you ear to the sub to hear it.

I'll keep going as the weather improves and I can get outside to inspect all the grounds at the dish, and on the side of the house where the cable comes in.

Thanks again for all of the responses!!

[rjryan]

Finally figured it all out with the help of Chuck at McIntosh - DC offset. I've traced it to the grid, unfortunately.

It's more bearable now that the weather is warmer, but I'll have to employ a decent filter at some point. I'm thinking that the new Shunyata Denali should do the trick. Now, to start saving up!

[phishphan]

Originally Posted by rjryan

Finally figured it all out with the help of Chuck at McIntosh - DC offset. I've traced it to the grid, unfortunately.

It's more bearable now that the weather is warmer, but I'll have to employ a decent filter at some point. I'm thinking that the new Shunyata Denali should do the trick. Now, to start saving up!

Warmer? It's 16 out here on the west side of Lake Minnetonka!

Glad you figured it out. I had a hum going for a while and it ended up being a over loaded BIT15 power converter. I upgraded to the PS Audio P10 to solve the issue.

[Still-One]

Originally Posted by rjryan

Finally figured it all out with the help of Chuck at McIntosh - DC offset. I've traced it to the grid, unfortunately.

It's more bearable now that the weather is warmer, but I'll have to employ a decent filter at some point. I'm thinking that the new Shunyata Denali should do the trick. Now, to start saving up!

If I remember correctly some responses from the Caelin and Grant indicate that Denali does not address DC in the line. I love the product but I don't think it will eliminate it.

Find a old PS Audio Humbuster III it will do the trick but might impact you in other areas.

[rjryan]

Originally Posted by phishphan

Warmer? It's 16 out here on the west side of Lake Minnetonka!

Glad you figured it out. I had a hum going for a while and it ended up being a over loaded BIT15 power converter. I upgraded to the PS Audio P10 to solve the issue.

A whopping 18 here in Moorhead :-)

Perhaps we could solve the whole issue with the new Tesla shingles and a dedicated battery!! 🤣🤣

[Jess]

Worth a shot!