ASambrook Posted January 13 Share Posted January 13 Hi All, Sorry if this has been covered somewhere else....I have recently been using my LT in studio rehearsals and noticed a low level hum when connecting via XLR....I have seen all the chat re xlr & phantom power, but that is not the issue...all my presets have a return block for adding my BOSS BR80 into return 1, so I can use backing tracks for practice. However, this block is causing "hum" even with nothing connected to it. The "hum" goes away when I remove the return block.....does anyone know why this is happening...? I don't really want to double my presents with / without return loop if possible ... Thanks Quote Link to comment Share on other sites More sharing options...
datacommando Posted January 13 Share Posted January 13 On 1/13/2025 at 12:23 PM, ASambrook said: Hi All, Sorry if this has been covered somewhere else....I have recently been using my LT in studio rehearsals and noticed a low level hum when connecting via XLR....I have seen all the chat re xlr & phantom power, but that is not the issue...all my presets have a return block for adding my BOSS BR80 into return 1, so I can use backing tracks for practice. However, this block is causing "hum" even with nothing connected to it. The "hum" goes away when I remove the return block.....does anyone know why this is happening...? I don't really want to double my presents with / without return loop if possible ... Thanks Hi, Not sure why you are picking up “hum”, but the first line of defence here would be the Ground Lift Switch, on the rear panel of your LT. It is there as a “hum buster” for dealing with this sort of thing. There can be many reasons for introducing ground loop hum in your signal. I see that you mention that you have a Return block in your presets, but didn’t say where this is positioned in the signal path, or how complex your presets are? Have you tried creating a parallel split B on Path1 (or Path2) where the actual input to it is designated as RETURN 1 (or 1&2) and set to Line level. Using the Returns as a dedicated input, you have an optional noise gate that might help cut out any excessive noise, and the audio from you BOSS recorder could then pass through to the outputs without going through any additional processing blocks. I also note that the output from the Boss 80 is on a stereo mini phone connector. Check whatever 1/8” to 1/4” jack converter is the right one for the job. You could use a splitter to connect the Boss stereo out to both 1 and 2 Return input sockets to see if that improves the audio signal. All 4 paths available in your Helix LT are stereo. It’s always a good idea to have a read through the Helix LT 3.80 Owner’s Manual for options on routing your signal. https://line6.com/data/6/0a00051afd86673ccb96424d9/application/pdf/Helix LT 3.80 Owner's Manual - English .pdf Hope this helps/makes sense. 1 Quote Link to comment Share on other sites More sharing options...
rd2rk Posted January 13 Share Posted January 13 How are you powering the BR80? It's not unusual for BUS powered devices to be noisy, it's a common problem with cheaper BUS powered AIs. If you're using a DC Power Supply, what kind? if it's a multi output are the outputs isolated? Is the PS connected on the same circuit as the LT? Are there fluorescents, rheostats or appliances on that circuit? If they're connected to the same power strip, is it filtered for EMI/RMI? Are you using a shielded cable to connect the BR80? Quote Link to comment Share on other sites More sharing options...
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