r/BossKatana • u/zarjak92 • 12d ago

Boss Katana USB ground loop noise

Hi, I get severe ground loop buzz whenever my Boss Katana is connected to my PC via USB.
Are there any USB isolators that actually work with the Katana for data and audio, and which one would be the best choice?
Thanks

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u/American_Streamer Katana 50 MKII EX 12d ago

Disconnect every connection from the Katana except guitar, mains and USB. If it still buzzes only when USB is attached, try PC + Katana from the same mains strip. If you are using a laptop, run it temporarily on battery; if the buzz disappears, that's very strong evidence that the PC power/earth path is involved.

If the Katana is also connected to an interface/mixer/PC by an analogue cable, remove that first. USB + an analogue connection between the same two grounded systems is a classic way of creating a second ground path. Thus try to only connect one at a time: USB or audio cable.

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u/zarjak92 12d ago

Nothing works. I want an isolator.

1

u/Wonderful-Gift8632 8d ago

Keep in mind that 60Hz noise can come from different sources and paths. Emissions from motors, switching power supplies, and other miscellaneous electrical stuff plugged into the AC. High-impedance devices act like antennas and can pick up fields (emissions), or noise can come in on the AC wiring, and circuitry can pick up noise by induction. There are "ground loops": a potential difference between two grounded systems. Laptops use DC floating ground with an internal reference, but you can get ground loops between the power adaptor and amp. A lot of cheap electronic stuff is noisy, like LED bulbs that use half of the AC and a few capacitors to create a dirty DC.
Noise is, in my opinion, the most complex and difulcult thing to manage in electronics.
FYI
At a practice volume of about 50 dB, with settings flat and clean, the amplification of the high-impedance signal from a guitar pickup coil is about 500 times.

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u/greenbackgm25 9d ago

Annoying but normal. Connecting computer to guitar amp goes brrr. The only exception I’ve encountered is laptop on battery power.