dukefx
100+ Head-Fier
- Joined
- Aug 20, 2008
- Posts
- 130
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- 27
I'm in need of a bit of help troubleshooting my sound system. I have a fully USB powered DAC with a separate power supply. I've cut power to the USB ports and used various cables and splitters to make my DAC work with a custom PSU. Here's the setup:
I've ordered a custom USB cable that has power cut on the PC side. The lines indicating the data and power going to the DAC are now one single cable. It should do the exact same thing my cable-jungle used to do without the need of an unpowered (no red and black wires connected) USB port. Here comes the fun part: I can hear a quiet ~1kHz hum. On top of that if I disconnect anything marked with a red circle the OS won't see the DAC anymore.
My best guess is that it's a GND issue.
Additional info:
- This only occurs with the new cable.
- Multiple PSUs have been used.
- DAC does not need a common GND, it worked perfectly without it.
- I've not taken the new cable apart to have a look if it's soldered as requested.
- There's an amp between the headphones+mic and the DAC, but it doesn't influence anything. Taking it out of the chain results in the same thing so I left it out.
I've ordered a custom USB cable that has power cut on the PC side. The lines indicating the data and power going to the DAC are now one single cable. It should do the exact same thing my cable-jungle used to do without the need of an unpowered (no red and black wires connected) USB port. Here comes the fun part: I can hear a quiet ~1kHz hum. On top of that if I disconnect anything marked with a red circle the OS won't see the DAC anymore.
My best guess is that it's a GND issue.
Additional info:
- This only occurs with the new cable.
- Multiple PSUs have been used.
- DAC does not need a common GND, it worked perfectly without it.
- I've not taken the new cable apart to have a look if it's soldered as requested.
- There's an amp between the headphones+mic and the DAC, but it doesn't influence anything. Taking it out of the chain results in the same thing so I left it out.
