Anyone using a lot of USB-powered #audio equipment knows how annoying ground loops can be. With this I've got 5x stereo isolators in a relatively small box.
This may be a dumb and irrelevant question, but is there a reasonable solution for USB ground loops? I ran into this with my OpenTheremin and it ruined the sound output quality.
No, it's a _very_ relevant question because that's exactly what this is for!
The _best_ solution would be for audio equipment manufacturers to include ground isolation in their USB-powered devices, but since that's outside a user's control something like this is the only option.
This box I built has 5 pairs of stereo audio jacks that go through those red audio transformers and that's effective at getting rid of those pesky ground loops.
Of course, you can buy pre-made isolators, but they're weirdly sort of pricey. I was able to order 10 naked audio transformers and 10 audio jacks for the price of just a couple pre-made ones.
I'm not familiar with the OpenTheremin, but if you have space inside the housing, you could wire these isolators _inside_ the housing so that the output from the OpenTheremin is _always_ ground isolated.
If you want to get super fancy you can use an op-amp to create a 'virtual ground'. Instead of using the 5V and USB ground, you'd use the virtual ground as the ground for your circuit.
Brett Edmond Carlock
in reply to jefftheworld • • •jefftheworld
in reply to Brett Edmond Carlock • • •No, it's a _very_ relevant question because that's exactly what this is for!
The _best_ solution would be for audio equipment manufacturers to include ground isolation in their USB-powered devices, but since that's outside a user's control something like this is the only option.
This box I built has 5 pairs of stereo audio jacks that go through those red audio transformers and that's effective at getting rid of those pesky ground loops.
jefftheworld
in reply to jefftheworld • • •Of course, you can buy pre-made isolators, but they're weirdly sort of pricey. I was able to order 10 naked audio transformers and 10 audio jacks for the price of just a couple pre-made ones.
jefftheworld
in reply to jefftheworld • • •I'm not familiar with the OpenTheremin, but if you have space inside the housing, you could wire these isolators _inside_ the housing so that the output from the OpenTheremin is _always_ ground isolated.
Brett Edmond Carlock
in reply to jefftheworld • • •I switched from USB to linear 120v->12v step down transformer, which helped, but still had some nasty noise.
Then I added an NVX XGLI35, which helped greatly, and built a Classic47 pre-amp (not yet installed in line).
I am hoping that should do it because I have been struggling to get it clean.
jefftheworld
in reply to Brett Edmond Carlock • • •If you want to get super fancy you can use an op-amp to create a 'virtual ground'. Instead of using the 5V and USB ground, you'd use the virtual ground as the ground for your circuit.
Brett Edmond Carlock
in reply to jefftheworld • • •