connecting my ubk fatso to my octatrack produces a very audible hum, while connecting the ubk fatso to my rme fireface does not. i’ve tried using balanced as well as unbalanced cables, same result in both cases: the octatrack’s inputs hum, the fireface’s inputs don’t.
can some of the more technically minded people around here tell me where this hum may emerge from and why it only occurs on the octatrack’s inputs?
thank you.
Sounds like a ground loop. Try using a stereo DI box or line isolator and see if switching to ground lift helps. See if using a grounded monitoring system makes any difference.
Make sure you’re using them on the same power line.
thank you alfred. i’ve recorded the hum (and normalized it to -18 dbfs) – does it sound like ground loop to you?
https://www.elektronauts.com:https://eu5.dh-cdn.net/uploads/db8181/original/3X/9/2/92265e87c22425c64487e87ad93cd3d8bd522e44.mp3
i’ve done a bit of research and it sure looks like ground loop in the spectrum analyzer:
and if it is indeed a ground loop, would this thing, put just before the octatrack’s inputs, likely solve it? https://www.thomann.de/gb/palmer_pli02_trennuebertrager.htm?ref=search_prv_7
thanks again
thanks plastic, i’ve tried different outlets but didn’t find much difference…
Yes it totally sounds like ground hum. Ground hum doesn’t strictly only have to be at 50hz. It often folds up and becomes audible as a multiple of 50hz.
Yes, I use these line isolators too and they do the job. Just be aware that it only gives you a XLR out. But there’s also a mono version from the same brand that has jack in and jack out. You could get two of those.
My first approach would be to check the grounding of the amplifying system though. And maybe try a DI box before it.
the mono version has no ground/lift switch though…
it doesn’t need one. the ground is lifted by default. isolating the grounds is all it does.
ah, ok – thank you
