• Registered: 2011-01-30
  • Posts: 66

Topic: Fireface UFX noise levels on instrument inputs are not equal?

I have turned on trs switch on mic 9,10,11,12 inputs and craked up the gain and that's what I saw:
http://img822.imageshack.us/img822/6128/trsnoise.jpg

meanwhile with trs set to off, inputs look like this:
http://img820.imageshack.us/img820/3784/micnoise.jpg

Nothing is connected to the inputs!
could somebody please explain why the instr input nose levels are 9<10<11<12 ?
different gains?
My firmware version is 342/110/336

Fireface-UFX, Mac OSX 10.6, Logic 9, BCF2000, AC-7 user, vocalist, live sound recording
  • Registered: 2011-01-30
  • Posts: 66

Re: Fireface UFX noise levels on instrument inputs are not equal?

Can anyone confirm if that's "normal" operation?

Fireface-UFX, Mac OSX 10.6, Logic 9, BCF2000, AC-7 user, vocalist, live sound recording

3 Reply by edgehill (edited by edgehill 2011-03-02 22:12:25)

  • Registered: 2011-03-01
  • Posts: 19

Re: Fireface UFX noise levels on instrument inputs are not equal?

Same here, figures fluctuate a bit but are within 1 db compared to your figures.

EDIT: plugged in a guitar with volume completely off.
Now all channels show equal noise floor (around 53dB).

  • gvr
  • ADAT user
  • Offline
  • Registered: 2012-05-19
  • Posts: 10

Re: Fireface UFX noise levels on instrument inputs are not equal?

I can't confirm whether it's normal but here's what I experienced:

1. With nothing connected and zero gain I see the channels fluctuating between -71 and -76.
2. I calibrated my setup for 94db and with the same signal (a 30mV signal from an Earthworks M30 measurement mic) I got 4.5db difference on Mic 9/10.

  • Registered: 2008-01-01
  • Posts: 3,025

Re: Fireface UFX noise levels on instrument inputs are not equal?

The interesting question is how those channels compare when something is connected?! As Edgehill already reported he gets the same noise floor once a guitar is plugged in.