Broken H&K 20watt valve

[harvema]

Hi guys
Wondering if anyone can help me out. My H&K 20th anni. valve amp crackled when i turned it on. Nothing was plugged in.
Took it apart to look for any blown caps and found this [see pic]
Just wondering if anyone knows if this could be the culprit?

[Dave Curtis, dB AudioTech]

First off, welcome to the forum!


If it's coming from the capacitor, then yes, it's highly suspect. You can DIY

> IF!! <

you know what you're doing. Otherwise, a good tech will fix you right up and do some other preventative maintenance, as well.

[soundguruman]

No, the leaking cap is not what causes the amp to crackle. Although it could be replaced...
You can clean all the controls and jacks, and re-solder the circuit board.
Also, it may just be a bad tube, so try a new one first.

[g1]

Hard to see from the picture but it kind of looks like the silicone they use to secure certain parts to the circuit board. Is there white silicone elsewhere on the board? That doesn't look like an area a cap would leak from, more likely the rubber seal in the other end.
Crackling could be caused by many things, for example a dirty tube socket, crackling tube, or a bad solder connection somewhere.

[harvema]

Thanks for the advice guys.
Any idea how to determine if a tube is shot?
I might have to bite the bullet and get someone who knows what they are doing to look at it

[Alex R]

caps don't normally leak at that end.

Try swapping in a known good 12AX7 for each preamp valve.

If it has a MV turn it down, if the noise doesn;t go away it's in the power amp. If you can identify the driver valve (the PI), pull it out to eliminate it. Still noisy, it's a power valve.