A ton of crackling during startup

[Jameson]

My typical startup procedure is to turn on the BeePre, let it warm up for a bit, then turn on the Kaiju. Before I’d hear absolutely nothing during startup, then music eventually once everything was energized. Now I’m hearing a lot of crackling and popping while the Kaiju energizes - about 3 seconds. It doesn’t happen once the amp gets energized.

Is this an early sign of some bad soldering or is this ok? Maybe just turn the BeePre down until everything is warm?

 

[Paul Birkeland]

Is it both channels in the Kaiju?

 

[Jameson]

I think so, but I’ll pay attention next time it happens. The Kaiju is physically closer to the left speaker so I hear that one for sure when I turn it on since I’m standing next to it.

 

[Paul Birkeland]

It could certainly be a solder joint.  You can poke around in the amp with a wood chopstick while it's running to see if you can fire off the static generation on its own, then that will give you a place to focus on for reheating/reflowing joints.

 

[Jameson]

Alright. That’ll have to wait until I’m moved into the new house and I have tools accessible to deal with it.

How does your answer change if it’s just one channel or if it’s both?

 

[Paul Birkeland]

If it's one channel, I would have to you swap the 300Bs and try again, then swap the 5670s and try again.  If the startup crackling follows a tube, then you have an answer.  If it follows a 300B, I would recommend reheating the solder joints on the tube pins themselves.

 

[Jameson]

Got it. I’ll check next time I start from cold. I turned it off a couple minutes and tried and got no noise at all, so it seems to be fine when it’s warm or has charged caps.

 

[Jameson]

Ok, definitely confined to one channel, so I swapped the 300B tube. The noise DID follow the tube. I'll see if I can track down a soldering station in this mess of boxes. Any tips for reheating the pins? Just a few seconds? Do I need to apply any solder to facilitate heat transfer, or will that muck up the pins?

 

[Paul Birkeland]

Not a little heat, a ton of heat.  There's not a lot to damage there.  The ends of the pins are actually hollow, so you can use just the tiniest bit of solder to get the heat to transfer from your iron into the base pin. 

 

[Jameson]

Got it. Thanks, Paul.

 

[Jameson]

That seemed to help quite a bit, but didn't knock it out fully. I'll give it another pass a little later.

 

[Jameson]

Hey Paul - it appears to have returned on that tube. I went back down to my station, cranked the heat up as high as it'd go, put a little solder on the iron, and held the iron on the end of each of the four pins for about 30 seconds each. It's long enough that the base of the tube gets warm. It still crackles, maybe even more than before.

Am I doing this correctly? Should I get a replacement?

 

[Tom-s]

Did the solder in the tube pins actually melt? If not, your effort was futile. IME it takes a whole lot of heat to make a good connection on tube pins.

 

[Jameson]

I believe it did. I felt some, for lack of a better word, push back from the pin like something was coming up from the pin and pushing the iron up a bit. It seemed to be floating on something. It's hard to explain.

I can take it back down and spend more time on each pin, though.

 

[Paul Birkeland]

try 2-3 minutes per pin. 

 

[Jameson]

Will do. Thanks!