Problem with Warwick Tubepath 10.1

[Olafrom]

Hi,

Just got used Tubepath 10.1. At first it worked fine, but after changing the tubes it suddenly started to rattle. Soon the rattle changed to a very low hum. Amp also lost its power. I tested the tubes and tried another ones.

I opened the amp and noticed that the grey cable (gain signal or gain hot) going from the gain potentiometer to the first preamp tube gives a popping sound (in very similar frequency that the continuous hum has) when I move or tap it. It's like lower freq sound of tapping a microphonic tube. Soldering looked fine and there was not any visible short circuits (<- Is that a real word?)

Does anyone have any experiences on this? Or any idea how to fix it?

I hope you understand what I've tried to say. I'm finnish and it's kind of hard to produce this tech talk.

 

[BassmanPaul]

If it worked fine why did you change the tube? Have you tried reinstalling the original tube??

Short circuits is good English.

 

[B-string]

You didn't by any chance move that cable when you changed that tube, is it too close to the tube (burning or melting the cable even internally)?

 

[Olafrom]

Great to hear that my english is acceptable.

Yes, i tried to put the old tubes back. Still humming.

Old tubes worked, but they had already given the best of them.

And thanks B-string! Gotta check that. Cable runs very close to tubes (cannot understand why), almost leaning to them, and there is ground and signal in that same cable. It could be possible. Actually, I thought that the hum sounds a bit like grounding problem.

 

[winegamd]

Yeah, it sounds like a cable break. If it is a ribbon cable, this is most likely your culprit. They are very fragile and the leads can break internally if moved around much.