Help :( Speakers making constant static sound I cannot figure it out


Speaker "whooshing" static sound

Other system setup photos for reference

So I linked to the video of the sound for reference.  It's been driving me crazy, so today I unplugged everything, took it all away from the console, cleaned it all nicely, and the plan was to, one by one, re-attach each component until the static returned, to try and isolate the cause.

 

Well, the only thing plugged in is the amp (Rogue Cronus magnum iii) and speakers (Focal Kanta 3), and the static is back.  It is a constant sound, there is no source plugged in, and the sound does not fluctuate at all when I turn the volume up or down, or turn the knob to change source, or even when I turn the balance all the way left or right, it seems to have nothing to do with the amp settings then, so where could it even be coming from?  I just checked the power tube bias and all 4 looked perfect.

 

TV is also unplugged, so there's nothing around to be causing feedback or rf interference that I can think of.

 

I don't have any other speaker cables to test against but did swap power cords between some components.  All cabling throughout is Nordost Heimdall 2, and is running through the Nordost QBase power distributor which has 1 each of the QK1 and QV2 plugged into it.  Main cable from the QBase to the wall is Shunyata as I needed a 20amp cord to work with that box and there isn't one in the Heimdall line.  Wall receptacle is a 20amp one that I installed (can't recall the make at the moment, but I believe I got it from a user on here some years ago.)

 

However, I tried skipping the QBase and plugging the amp straight into that wall outlet, no change.  Then I tried plugging it straight into a different outlet, still no change.

 

Based on the the type of sound heard in the linked video, and the details that it seems totally unaffected by volume, balance, source selection, etc., what do you think it could be?  Does it seem likely to be an issue with the speakers, speaker cables, or the amp?  At least that would narrow down how to address it.

 

Thanks for any helpful suggestions.

 

chrisryanhorner

Showing 5 responses by sls883

Are you hearing the noise in both channels?

I would guess it's a bad tube, but I'm guessing. 

Do you have any extra tubes? I wouldn't run it with a tube missing. I don't know if it would hurt anything. 

It looks like the 12AU7 is a preamp tube common to both channels. If you are getting noise in both channels, I would replace it. 

If you are only getting noise in one channel, move the tubes on the left channel to the right side and vice versa.  If the noise moves to the other channel, it's probably one of the tubes on the side that is noisy. 

Have you said if it's one channel, or both?

Tubes don't always last a long time. It depends on the design of the component.

You might get lucky and it's the 12AU7 preamp tube that appears to be common to both channels.  I would replace it first. 

I did have a conrad-johnson preamp that produced a static sound out of one channel. Replaced all of the tubes multiple times. Fortunately, the seller let me return it. From the research that I did, it could have been a resistor, but I didn't want to go through the pains of trying to get it fixed.