Re: [linux-audio-user] The famous "Jack Hum" (Can't record and desparate)

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Carlo Capocasa schrieb: I had a quite similar Problem (that ceased after i stop using a Lamp-dimmer in the room next door) and i am sure to call it "network-hum" instead of "jack-hum". Little poor innocent jack is just software - has no capabilities to fetch stuff from the real world, that is not *there* in the first place ;-) some 20 Years of fightig (unwanted) noise in audioelectronics give me the strong feel, that your problem is caused by hardware/cabeling/powersupply. You have mentioned, that you have a fw-sounddevice and that the hum unfolds, as you start up jackd. Jackd fetches the stream from the fw-device and if it causes humming jackd naively thinks, you want everything you precious soundcard generates ;-) here are some suspects: power-supply of the device: try changing its connection to the ac-net (vulgo: connect it to another powerline - preferably the same, you have your Computer connected to, rule of thumb: all devices should share the same fuse.) cabeling of the stuff, that is connected to the device: Microphone-cables should be hi-class, adapters shall be at the same fuse (see above) if you need phantom-power, fetch it from a mixer/preamp, that gets its current from the same etc... Neon-lights, dimmers, everything that needs a power-transformator. It can be the cute lights for the aquarium in the room next door... those produce electromagnetic waves that can pollute badly grounded/shielded cables, device-hulls etc etc If you play Guitars, Synths etc hardwired (eg. with an electric connection to the network/system), try to use direct-injection-boxes. network means: everything that has an electrical connection to whatever device you use, including stuff like modems, ethernet AND ac-plugs, electronical instruments, Lamps, hair-dryers, chainsaws, peripherals like printers, scanners, cameras etc. connected via USB, Firewire, ethernet, guitarcables, ac-adapters - you name it. good luck