Hello,
I finished building my crack + speedball this summer. But since the build, there is a noticeable slight hiss / static / white noise coming from the right ear of my headphones. This hiss happens even without the input RCAs plugged in. It also happens even if the volume pot is all the way to 0 or OFF. I tried my HD6XX and then HD800S with the same result. I tried plugging the amp in a different socket and then in a different room in the house with the same result.
To give you a bit more info on the hiss, here is what happens chronologically when I start the amp :
1. First instant, a "surge" of hiss in the LEFT channel
2. Quickly this LEFT hiss disappear and becomes inaudible
3. Then a surge of hiss in the RIGHT channel (as if it transferred from left to right, but i'm not sure if that's thing in electronics or not)
4. The right hiss kinda progressively becomes quieter but is still audible and that"s the issue
The amp passed the voltage tests present in the manuals. I think, if i remember correctly, that this hiss was present even before the speedball upgrade. I though the speedball would reduce it to zero but I was wrong. Today I re flowed all the solder joints with a bit more solder. I also checked continuity with a ohm-meter. This unfortunately didn't solve the issue. I "cleaned" the tubes pins by inserting them repetitively, didn't solve it either.
Now I don't really know what else I could check, so if you have experience with a similar problem, can I ask for your help please ? I'm thinking about ordering a set of tubes to see if the problem comes from the tube but if you have any idea before I order them please feel free to tell me. Thank you !
