[ArmAndHammer]

I bought it used. Got it for Christmas last year. Far as I can remember it wasn't doing it when I first got it. I haven't been using it (or listening to my HP much lately) so I can't remember when it started. Anyways, left side is a crackly hissing noise, right size is a buzz. At first thought it was because the amp and DAC was sitting on top of my computer tower although my previous LD1+ didn't do this while sitting in the same spot. So I moved it anyways...noise still there. Gets louder when I turn up the volume.
 
Any ideas? Possibly tube related? I want to swap out tubes to see if that does anything...I don't remember how to change the jumpers...I need to look it up. I've just been lazy. I have a set GB-408A tubes that are lovely but I seem to have missed placed them 

 

[ArmAndHammer]

I'll add that I know it's the amp because when hooked up to my cmoy using the same DAC...I don't get the hiss/buzz. 

 

[ArmAndHammer]

And it does it with all 5 of my headphones so it's not HP related.

 

[ArmAndHammer]

Tubes...it was the tubes. I finally looked up the settings for the 408A tubes, through my oh so lovely NOS Sylvania GB-408A's in and fired it up....oh my GOD!!!! I remember now why the LD 1+/Grado match up is one made in heaven. And no more hiss or buzzing. Guess the little guy was telling me it was time for a real set of tubes.