SteveMac said:
Well, I tested the tubes they all checked out good. Put them back in and found while putting them in that one was a little difficult to get back in. I had to twist it around a little. I fired it up again and VIOLA ! the noise was gone and it sounded sweet! Then I realized that, that one difficult tube was not lit. When I repositioned it, so it lit up again the noise came back with it. So I've narrowed the culprit down to that one tube connection. So, does anyone know if it's safe to run tube gear (until I get it fixed) with one tube taken out . I've no idea what it's job is.
Unrelated but seemingly relevant post (from Google's cache..aka this is a quote from some random website that no longer exists)
Begin quote:
Hello,
I have a Fender Hot Rod Deluxe tube amp. Lately it has been sporadically making a loud distorted static noise which overpowers the sound of my guitar and sounds terrible. Usually the harder or louder I play, the more this problem appears. Do you think I need to replace my tubes? If not, what do you think the problem is? I would greatly appreciate any advice you can give me.
Thanks, Preston Hart
Gaithersburg, MD
Preston,
This definitely sounds like a vibration sensitive problem since you mentioned that the louder you play, the more the problem appears. This could be caused by a plethora of problems, of which tubes could definitely be one. When was the last time you replaced your tubes? General rule of thumb for output tubes is 6 months to 2 years depending on frequency of use and how loud you play the amp. For pre-amp tubes it's usually when they become problematic, but lets see if we can first do a little preliminary diagnosis.
First, while the amp is on, turn down all the controls to zero. Take a pencil or chopstick and lightly tap on each power tube (the large 6L6 / 5881's) individually. If one of them appears to create the same sound that you've been experiencing, then you may have found the source of the problem. Just to be sure, put the amp on standby for a minute, wait for the tubes to cool, and remove the suspect tube. Take the amp off standby (yes it's OK to do this with one tube missing) and tap on the remaining 6L6. If the noise appears to be gone, then you may have found the faulty tube. Just to be sure, put the amp back on standby and wait for the tubes to cool again. This time take the 6L6 that's in the amp and move it to the other socket. Fire the amp back up and tap on the tube again. If the noise is now present, then it may not have been the other tube, it may be a faulty tube socket or associated connection. That's gonna’ require a trip to your local service tech.
OK, if the output tubes seemed OK, then lets check the pre amp tubes. (You may first want to pick up a spare 12AX7 for troubleshooting purposes, and to just have around for a spare anyway.) Turn the amp on and set all the controls (except the reverb) to their mid positions. Lightly tap on the pre-amp tubes and see if any of them appears to create the problematic noise. If so, try replacing it and see if that cures the problem. If not, replace the original tube. At this point we've pretty much ruled out the probability of a tube causing the problem. There's one more thing you can try before the amp takes a trip to amp hospital.
Play the amp, and when it starts making the noise, take a short jumper cable and plug one end into the effects send jack, and the other end into the effects return jack, effectively jumping out the signal path thru the jacks. If the problem stops then you may have a dirty effects loop jack. Turn the amp off and spray a little electronic contact cleaner and lubricant into the jacks and work the plugs in and out a few times. Leave the plugs in for a while to let the contacts dry out (overnight if you can) and then try the amp again. If you still have a problem at this point, the amp probably has some internal intermittent connections and needs to take a trip to the repair shop. Be sure to give the technician all the information you possibly can. Does it happen when the amp is hot or cold? Does it happen when all the controls are turned down? Does it happen in the normal channel, overdrive channel, or both? These are all questions who's answers are very helpful in the diagnosis of a problem, and will be valuable information to a good technician.
Good luck. Hopefully you'll have a healthy Hot Rod soon
:End quote
..heh!
and you can't hear it through the headphones you can only see it on the needle until you play it back. 
... or what am I missing here?
