Hissing when connected to laptop

[oguinn]

It might help to post some pictures around the 6080 to see if there's anything people could spot. A lot of time those loose connections can be affected by tapping the chassis near where they exist. Someone had mentioned using a chopstick (non-conductive) to prod around those connections while listening to the amp with a crappy set of headphones to see if hitting any of them causes a pop. If so, that's where you focus.

[Paul Birkeland]

Prodding the connections with a chopstick and cheap headphones attached would be a good idea. 

[benzxc]

Here is a photo of the 6080 socket. I just noticed there are two extremely loose tube sockets. Not the solder joints but the pin sockets connecting to the ceramic (?) base. Could these be it? 

I tried the chopsticks and cheap headphone but no noise!

[Paul Birkeland]

All of the lower terminals on that terminal strip could use more heat and a tiny bit more solder.

The red wire going to B6 needs to be pulled through more and wrapped around the connection at the socket.  The same goes for B3.

If the stripped bit of wire at B3 touches the stripped bit of wire at B2, you will start smoking parts in the power supply, so I would reheat those joints and pull the wire through a bit so the jacket is closer to the socket pins, then wrap the stripped wire up and over the socket pins and solder the bit of the wire that's wrapped over the pin.  (Ditto for the joint at B1, but not B4.  B4 is what you want to go for)

[benzxc]

Thanks, PB!  Just did it, although the noise is still there.  Guess I will just leave the crack on for a few days and see.  In any event I will soon have a new tube to see if the issue is with the tube.  BTW is there a suggested max continuous number of hours/days that I should keep the crack on for?  Don't want to ruin it by doing this!

Thanks again,
Ben

[Paul Birkeland]

BTW is there a suggested max continuous number of hours/days that I should keep the crack on for?

My estimate would be about 3-5 years of constant operation before you'd probably burn up the tubes and 30-80 years for the caps to wear out.

[benzxc]

Whoa! Great to know, thanks PB! 

[oguinn]

Hopefully you'd have it fixed before that 80 years runs out!

[benzxc]

Hopefully you'd have it fixed before that 80 years runs out!

Fingers crossed! 

[benzxc]

Just an update to all who helped me and for all who have the same experience with the noise and is wondering:

Having left the Crack on for about 50 continuous hours, the weird low volume noise in the right channel has mostly disappeared. It resurfaces once in a while for a very short period of time, and the volume has noticeably decreased. (It was low volume to begin with, and has gotten even lower to the point it is unnoticeable unless I am consiously looking for it.)

 I am going to leave the Crack on for a couple more days to see if the noise will disappear completely.  Very very satisfied with the Crack! Excellent sound! Even if it doesn't disappear, I think I can live with it for now.

My new tubes haven't arrived yet but once they do, I will pop them in to see if it happens with the new tubes.

Thanks to all!
Ben

[benzxc]

70+ hours burn-in now and the sound has no re-appeared!

Although I do have a quick question: I just turned the Crack off and flipped it around to check on the wiring and I noticed this weird sound when I flipped it over.  It sounded like there was a loose part in the Crack.  I checked like crazy everywhere to see if there may be any loose parts but didn't find any.  I could not pinpoint where the sound is coming from but the sound is not coming from the tubes themselves, and I tightened all screws as much as I could.  I shook the Crack a few times and the sound reappeared.

Could the sound be coming from the tube sockets?  I noticed that some of the sockets are very loose.

Is this something I should be concerned about, or should I just go ahead and use it and deal with it if an issue pops up?  Like I said, the Crack is functioning perfectly now.

Thanks,
Ben

[Paul Birkeland]

If there are no tubes in the sockets, the pin contacts will move around a little bit when you shake the Crack.  You want this though, those contacts need to move when you insert a tube.

[benzxc]

Thanks, PB. The noise occurred when the tubes were both in the socket.