Topic: Question re: line level into UFX mic/line inputs

Hi there

I'm wondering how to get a line level signal into the mic/line inputs (inputs 9-12) of my Fireface UFX.

I have tried feeding a 1kHz -20DBFS signal at mic level and it registers at -27DBFS when connected with a TRS jack and the input set to Instrument in TotalMix.

I've read through the manual but can't find an accurate answer. It seems to imply just setting the input to Instrument should be sufficient for a line level signal but I'm losing some level and wonder if there might also be an impedance issue?

Can any UFX users shed some light on this please?

Thanks in advance.

Re: Question re: line level into UFX mic/line inputs

There are a number of items to consider.

When you switch the UFX to 'Inst' you are going to unbalanced  input which means you may lose 6dB, (UFX manual, pg 104).
'Inst' inputs are unbalanced because that's the mode used by instrument pick-ups (TS) as opposed to TRS.

Much better to use a rear TRS input for 'line' input levels, Z is 10kO balanced.

Not knowing the source Z of your signal, there may be mismatch with the 800kO 'Inst' input.

If you need more level turn up the gain on the channel, that is its purpose.

Re: Question re: line level into UFX mic/line inputs

Thanks for your reply.

I didn't realise the front line inputs were unbalanced only.

I'm already using all the rear line inputs. I have a few more preamps I want to connect.

The source impedance of the test signal was 100ohms so yes they did not match.

Re: Question re: line level into UFX mic/line inputs

No problem using the 'inst' inputs with balanced signals, just make sure your UFX and preamps share the same AC power circuit.  You do lose 6dB but one can just add some make-up gain.

I've used my UFX 9-12 inputs for all sorts of unbalanced signals, no problems.  (hifi cassette decks, ISA428, etc.  Sometimes I even use them for mics and instruments!)