Wiggle kt170 base

Long story short. The culprit is actually 1 of the nos preamp 717A tube I bought last month in pair. I've reversed those 2 tubes and the hissing has migrated to the left channel. I've taken those tubes out entirely and replace with something else and the hiss has disappeared entirely. 

So weird for 1 to develop hiss just when I swap back in some power tubes. Welp. Guess it's time to try the famous Tesla ef806s I've always wanted. Haha

Hi fellas,

That orange/red base at the very bottom is very slightly wiggly from the metal part. I've tried to adjust all the tubes randomly and the hiss/static is still there but very low db now. Like those old tvs when the channel has no signal. The hiss slightly got louder randomly and then went back down. In the past it has been totally silent. No big deal. I don't think this little mishap is worth more of your time. Ty, I'll ask for more help if the situation gets worse.

One quick question. So the amp has 4 power tubes and 4 preamp tubes. If the issue is the right channel that usually means it's the 2 tubes on the right side?

Unless you swap the tubes in both sockets to see if the hiss stays with the tube or the socket, there is no way of telling if it is a bad tube or a bad mechanical connection. You could have a bad tube and it decided to show itself that day. Or you could have pulled the tube out or inserted into the socket in such a way that loosened the socket connection. Or... the socket could be soldered to a circuit board and the high heat compromised the solder joint and wiggling tubes in and out of that socket broke the solder joint.

Changing tubes should not cause clicks, pops or hissing. If the socket is loose, get it replaced or repaired ASAP. And if the tube is what is loose @jetter give perfect advice.

If the glass envelope is not glued to the base well the tube could be compromised and could prematurely loose vacuum.  If the silver getter turns white that’s what’s going on 

If the tube is loose in the socket, one way to address the problem is to re-tension the socked holes as mentioned above.

There is an easier way to address the problem I have used several times and was recommended by a distributer: using a very small pair of pliers, gently alternate bending every other tube pin in and the next pin out.  Less than a hair is all it takes.

Any play in the tube’s base / glass , you should get rid of that tube immediately.   If the tube is loose in the socket the socket’s holes need to be re-tensioned.  They are not gripping the pin well.   This can potentially be harmful and should also be addressed 

When you mean loose base are you talking about the physical connection between the tube and socket or is the tube’s base wiggling, is the glass not cemented to the base ?   

Assuming you unplugged and plugged the proper way and the tube does not show any play on its integral base then check amps tube base for any slack or whether there is a broken joint. Seems to be a bad connection (rare medium pop) and hiss from that channel.