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  3. 192815-122012

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
carlsbad2's avatar
carlsbad2
1,719 posts
 

You don't have spare tubes?  Do you have spare lightbulbs in  the house?  tubes are consummables.  always have a spare set.  

Powering up with a tube missing will generally not cause a problem but will not tell you anything since the amp will not work with the tube out.  the static will likely go away, but a new tube may not fix it.  In other words, you have to replace it with a good tube to know if you've found the problem.

Jerry

sls883
460 posts
 

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. 

thecarpathian's avatar
thecarpathian
4,708 posts
 

Even though it appears a tube is the most likely culprit and since you have no spares to check it out, I’d still call Rogue, explain to them what’s up, and see what they say about ways to possibly rectify it without causing damage.

chrisryanhorner OP
17 posts
 

When a light burns out, I go to the store and get a lightbulb, I'm not living in a bomb shelter full of soup cans.  Tubes last for years and can be pricey depending on what they are, so no sense in blowing money just to stick them in a drawer for half a decade and let them collect dust.  

I'm happy to replace what needs replacing now, just need to determine what exactly that is.  There's a repair shop near here that probably has some, I can see what's available and use those to test each socket until I find the culprit.  Maybe I'll take this opportunity to try some alternative tubes vs the stock ones supplied with the amp, it could turn out to be a fun development after all.

thecarpathian's avatar
thecarpathian
4,708 posts
 

When you see today's prices for quality nos tubes, you're gonna wish you bought them a half decade ago!

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