Stereomour II Left 12AT7 issue

[adlehman]

Hey y'all,

After a few months of smooth use, my left channel has developed an issue.

It started as a slight hum that could be diffused by gently nudging/wiggling the left 12AT7 tube, but it has now become a scratching/popping sound in addition to the hum. It comes through sporadically and is loud - when you wiggle the tube now the scratching/popping still persist, sometimes worse, sometimes a bit better.

Tried to look around for anything obvious but couldn't find anything. I also switched the L and R tubes to test if it's the tube itself but it doesn't appear to be that either.

My next step is to really just triple check the solder connections on everything attached to that little terminal for the 12AT7. I gave everything a proper poke/tug and no wires appeared loose.

Attaching some photos but the light was a but low, let me know if a close up of anything is needed and I can provide. If anyone has any tips I am all ears!

 

[adlehman]

Adding more photos here:

 

[Paul Birkeland]

You'll want to get a wooden chopstick and hook the amp up so it's running flipped over with some cheap speakers connected to the outputs. Poke around the circuit with the chopstick and eventually you should find a spot or two where you can poke and create the noise. Do keep in mind that the connections ad the tube socket and the places where those connections land are very much subject to inspection!

 

[adlehman]

You'll want to get a wooden chopstick and hook the amp up so it's running flipped over with some cheap speakers connected to the outputs. Poke around the circuit with the chopstick and eventually you should find a spot or two where you can poke and create the noise. Do keep in mind that the connections ad the tube socket and the places where those connections land are very much subject to inspection!

I'll get to it, thanks Paul!

 

[adlehman]

You'll want to get a wooden chopstick and hook the amp up so it's running flipped over with some cheap speakers connected to the outputs. Poke around the circuit with the chopstick and eventually you should find a spot or two where you can poke and create the noise. Do keep in mind that the connections ad the tube socket and the places where those connections land are very much subject to inspection!

Welp, a lot of things I poke throughout the chain cause a different pop or hum to occur.

I presume I should go back through the channel connections and sure up the solder joints as a next step?

 

[Paul Birkeland]

Anything you poke at that makes a pop needs to have its joints reheated on either end.