Hissing when connected to laptop

[benzxc]

Thanks, Bernie! Will do so right now to see if it makes a difference.

Any suggested/proper way to clean the pins?

[Paul Birkeland]

Is this noise still there with nothing plugged into the inputs?

[benzxc]

Hi Paul, yes the noise is present when the RCA inputs are not connected.

Thanks,
Ben

[Paul Birkeland]

Do you happen to have an ethernet over powerline kit in your home?

[benzxc]

Hi Paul, I don't have that, unfortunately.

[benzxc]

I just noticed that one of my heatsinks is not entirely in the socket. Attached photo. Could this be the cause of the weird low volume hissing sound, or is this unrelated?

Even if unrelated, is this something that could cause serious issues that I should fix now?  I ask because I am a little hesitant to make any big and unnecessary moves on my crack at this point for fear of messing something else up. Of course, if this is necessary to fix I will do it.

Thanks!
Ben

[benzxc]

Oops, photo here.

[Paul Birkeland]

That shouldn't cause a problem.

[benzxc]

Phew, good to know. Thanks for your help as always, Paul.

The noise occurs sporadically. It is low enough in volume that I can live with it if I can't fix it.

However, once I get those new tubes I will report back to see if anything changes.

Thanks to everyone for all the help so far!
Ben

[Paul Birkeland]

I would also suggest doing the modification I posted earlier on this thread, as you may have a polluting device somewhere in your house, and that will give you some extra isolation.

[benzxc]

Thanks, Paul!

[benzxc]

So I did some experimenting at home today and I think I isolated the source of the noise.

I unplugged all electronic appliances around the home but the noise persisted. Knocking around the crack, I noticed that if I tap at the 6080 power tube in a certain location, the noise decreased, and in one instance even disappeared. (I'm not sure if it actually disappeared entirely since the volume was small to begin with but it decreased noticeably. )

Does this mean that the noise comes from a noisy tube?

I read through the board and noticed others with similar issues and apparently some suggestions in these circumstances were, in addition to changing tubes, to leave the crack running for a few days to let the cathodes form. How many days should I do this for? Do I need to have music playing while I leave it on?  And at what volume?

Thanks!
Ben

[Paul Birkeland]

Yes, you could certainly leave the Crack on for a few days.  You don't need any music playing and the position of the volume control doesn't matter.

Physically tapping on a part of the amp and experience a difference in performance usually suggests a loose connection in the amp or possible just dirty pins on the 6080.

[benzxc]

Thanks, PB.

[benzxc]

Is it still suggestive of a loose connection in the amp if only tapping on the 6080 changes the noise, whereas tapping on the other tube does not change the sound at all.

I have checked my joints twice and reflowed them as well. Im afraid doing them again at this point might do more harm than good. Of course, I will do it if necessary. Just wanted to make sure before I go probing in again with my clumsy hands.

Thanks!
Ben