HeadPhone HUMMMMMMMMMMMMMMMMMM

[wyr2hs]

I have this horrible hum in my head phones, can any body pin point it
heres my signal chain
Instrument to a direct box to 24in 4 out snake or mic then to snake, into a mackie mixer- channel inserts into a patch bay- depending on how many instruments im recording at a time the signal goes to a rolls tube mic pre then to a phonic PCL 3200 compressor, then into a digi 001 input, then mounitering it comes out of a digi 001 output into a mixer channel and the aux sends send it through the snake into a head phone amp via mic chords, and then in to head phones.
thank you

 

[Sennheiser]

Is the hum in your monitors too?

Bad ground on the headphones.
Ground loop problem within your system.
Gain turned up too high on something.

 

[BigEar]

wyr2hs,

It sounds odd that you would come out of the Mackie insert into a tube preamp. That signal path then has two mic preamps in it which would have enormous gain. Suggest you run the mics into the tube preamps and then to the line in on the Mackie (mixer) channels. I would not suggest running non-preamplified microphone signals through a patch bay.

Ground loops can be a real source of problems. This may be the case if the hum is perceptible when all inputs are quiet (no sound). I have a few suggestions. 1) Keep it neat. Don't use 12 foot cables where 3 foot ones will do. If you're stuck with long ones, bundle up the excess. Bundle up excess length on your power cords too. 2) Keep all audio cables away from power cables. 3) Try putting the mixer, preamp, compressor, on one plug strip. Don't plug in your equipment into various plug sockets around the room. 4) Do not run speaker wire, or power cables of any kind alongside the snake cable.

The other source of hum could be that your coming out of the mixer channel insert, which is unbalanced, and plugging that into the tube preamp. You would have to crank down the mixer channel trim gain in order to keep the tube pre from clipping. This means all the power line crap that gets into your unbalanced connection will be at the same level as your mic signal. In english, lots of loud hum. Plus, any ground looping in this path will make things much worse.

It sounds like you want a flexible system. What I would do is set up the tube pre in such a fashon that the snake XLRs could plug into it or the mixer channels. The tube preamp output goes to a dedicated mixer channel (Line in). One mixer aux channel output to the compressor input. And finally the compressor output comes back through a mixer channel or aux return. The rest you can work out according to your needs.

JJ