Hummm... [resolved]

[oldvstar]

I recently retrieved my Crack from my son, bought some HD6xx headphones and using an old cell phone for streaming from Tidal I have been settling in to listen to music through the Crack again. The old phone was a temporary solution just so I could start listening to music while I waited for a Wiim pro plus to arrive. I now have the pro plus and my first listening session with it was both positive and negative. The positive is that I'm hearing much improved sound quality, this justifying the purchase. The negative is that I now hearing a nice 60hz hum through the headphones. The pro plus is powered by 5vdc through an USB C cable connected to an included wall wart. I'm wondering if putting an opto-isolator inline with the USB C cable will solve this, it maybe someone here has dealt with this and has a simple solution.

[Paul Birkeland]

https://forum.bottlehead.com/index.php?topic=11676.0
Try this first!

[oldvstar]

Thanks Paul, for 0.63 cents plus shipping this is a cheap and easy thing to try.

[Paul Birkeland]

While you're waiting, also be sure that the power transformer screws are tight, and let us know if you happen to have painted the bottom side of the top plate.

[oldvstar]

Thanks Paul, the diodes did the trick, no more hum. Also, transformer screws are tight, and no, I did not paint the underside of the transformer top plate.