My bottlehead crack /w speedball killed my headphones

[Th3RadMan]

I've been running my crack for a few months without an issue, but today out of the blue I turned my crack on and pop.  There was a loud pop on the right channel and after that the volume on the right channel of my HD650's went down by ~90%.  It is exactly what happened to this guy.

https://bottlehead.com/smf/index.php?topic=11626.0

The wires are all still connected fine and the voltages check out, the 0A and 0B are still a tad high at 110V, but the same as before and nothing crazy.  But now I have a pair of useless headphones.

I have been using the original tubes and I haven't done anything to them since I finished the build. 

Naturally now I'm kinda pissed and I don't want to use it til I figure out what happened. I'm also assuming there is also no sort of coverage on cans that are hooked up, especially since this is a diy kit?

Any ideas?

[Paul Birkeland]

You almost certainly have a solder joint on the headphone jack that isn't well soldered, which has allowed DC to pass and burn up your headphones.  It would be a good idea to post some photos of your build here and we can look things over for you.  I have yet to see a failed 6080 do any damage to a pair of headphones plugged into a properly built Crack, so I would focus more on the build and not worry too much about the tubes.

[Doc B.]

I agree with PB, this sounds like a case of needing to reflow the solder joints to fix the bad one. 

[Th3RadMan]

I have several pictures to post through imgur, but apparently I'm not allowed to post links. Unless I'm just being dumb.

[Paul Birkeland]

You can post the URLs, but not embed the images.  We have had some strange issues with the forum software glitching out badly with externally hosted images posted in-line here.

[Th3RadMan]

https://imgur.com/a/jGZYSzI

[Th3RadMan]

https://imgur.com/a/jGZYSzI

There we go, apparently I just couldn't post links yet since I didn't have 5 posts

[Paul Birkeland]

The 2.49K resistor on the headphone jack on the outboard side where the right channel feeds looks like it might not be all the way soldered.  Before you reheat it, you can tug on it with a pair of pliers to see if an end moves.  I would also pull on both black wires going to the headphone jack to be sure they are both tight.

This is a big part of why we recommend bending leads around a terminal for half a turn.  This gives a larger mechanical connection and a tight place for solder to flow into.

[Th3RadMan]

Interestingly, the left channel (white wire?) resistor was completely loose.  The right channel was fine.  Could that have been it?

[Paul Birkeland]

I would keep looking for loose connections.  That loose resistor would be a culprit to potentially cause some damage to the left headphone driver as you've noted.  I would recommend working your way back from the red wire on the headphone jack back to terminals 6-10, then to the octal socket and tug on everything and reflow any suspicious joints. 

[GLF]

Bummer on the damaged headphones. You can get replacement drivers from Sennheiser for a pretty reasonable price. The HD600/650 are pretty easy to disassemble/reassemble.

https://spares.sennheiser.co.uk/pro-audio-headphones/sennheiser-hd650-spare-parts/sennheiser-hd650-driver-300-ohm-092855.html The price drops a bit when you toggle VAT off. I can't find them on the Sennheiser US site, but I am sure the customer service folks could help you out.