Hey all!
New Crack+speedball owner here. This was my first time building something like this all by myself.
Let me start with that the base Crack worked flawlessly, no noise, just a pleasant sound all around.
However, ever since installing the speedball upgrade, a really noticable buzzing sound is present whenever I turn the volume up to 55-60% and getting louder as I turn it up more. Now I know that territory, above 60% is basically ear hurting, just mentioned it if it would help. I usually listen around 50-55%
All LEDs are lit up, all resistance and voltage checks are good. The only 2 values that are slightly off are OA: 113V and OB: 105V on the big board.
Do you think by doing the mod mentioned by Paul
https://forum.bottlehead.com/index.php?topic=11676.0 would solve or at least mitigate this? Or its a completely unrelated issue/or this is normal and that fix wouldnt work? The buzzing sound is gone if I disconnect the DAC from the Crack.
I used basic 60/40 solder, with the soldering iron at 380 °C
I attached some pictures, would be happy to make some more if you need it.
Thank you!