[zantetsuken]

Over the past few weeks I've noticed that my Audeze LCD2s generate a noise in the left channel audible as pops and cracks, it's only in this channel and the sound goes to the right channel if I plug the left jack into the right speaker of the headphone. The setup I've got is a USB cable connected directly to a Bifrost Uber and a Lyr. I'm using the original stock tubes that came with the amp, I'd say they probably have close to about 1000 hours on them at most. I'm wondering if the tubes can do this or is this a more serious issue? The pops and cracks have a waxing and waning pattern, it's quite irregular and does not become better or worse with volume control. The music still plays normally, the noise is audible in the background at low volumes with the music playing. It's present even with the Bifrost switched off. I'm not at all experienced with tubes and their issues when they manifest as this so your help and advice on the matter would be greatly appreciated. 

 

[mmedeiro]

Try a diff USB cable, this was the issue with my Fostex HPA8. Replaced the stock cable with a shielded cable and all popping went away.

 

[amalgamist]

Can also swap the tubes to see if the sound goes into the other channel, if so then it would indicate that the tube might be going bad.