Connect with UCX...

Hi there , I was posting this on the RME website but for some reason their forum hasn’t been working properly for the last few days that’s why I have posted this here ……… so if there is any RME users who could help me out PLEASE!
I have 3 key boards, 2 mics and I want to connect with UCX so how can I do this? Please see attached pic.
Previously in UCX I connected 1 keyboard L/R output in the front 3, 4 input and second 2 keyboards L/R outputs went in to back panel of UCX 5, 6 & 7,8 inputs but I was having low volume problems and just recently I was told “the back inputs are not for instruments that’s why I am getting low volume the back inputs are just for compressor and effects processors” He also told me that I need to get
Audient ASP880 or Focusrite OctoPre MK2 to connect everything properly!- is this all true do I need to do all this, its not worth buying such an expensive interface just to find out it doesn’t do what it should do I really need to spend more $$$$$$$$$$$!

Should be fine into line inputs as you had it…assuming you used TS/TS cables only.

Are you sure what you think is low volume is a problem and not just normal level you’d expect from a synth into a line in.

Can you give a metered level (RMS rather than peak)

From the manual:
The Fireface UCX uses the following level references:
Low gain

So you can set 3 different levels in totalmix, low gain, +4dB, -10dB
For keyboards it should be set to -10dB, well most of the time some have more output than others.
-10dB is the most sensitive.

I understand what you are saying, but when I use the front panel UCX 3,4L/R inputs it gives me normal volume but when I use the back inputs it starts giving me low volume!
I plugged in each keyboard individually in the front panel of UCX 3,4 input (I even tried the keyboard main volume at 50% and it gave me normal volume in total mix the graph bar was at 0db )
But when I plug in at the back panel 5,6 or 7,8 inputs of UCX even if I have the keyboard main vol at 100% it still give me low vol in total mix!
Anyhow coming to the point please just tell me do I need to get Audient ASP880 or Focusrite OctoPre MK2 to use with my UCX for recording my Keyboards or not???

No as I said change the input sensitivity on the line inputs to -10 dB, they are probably set to +4dB.
You do that in totalmix, there isn’t a knob or button on the UCX to change the input sensitivity of the line inputs.
No need to go out and buy preamps.

Right, in TotalMix, on the input channels, click the wrench icon and check the input setting(s)…

Thanks to Peakae and Sid Chigger, now I found the level input gain which was on -10db that’s why there was such a problem.

Now my second problem please tell me can I connect 3 keyboards at one time into my UCX? Because I have been told by a sale advisor that ONLY THE FRONT PANEL INPUTS 1,2,3,4, ARE FOR INSTRUMENTS AND BACK PANEL INPUTS ARE FOR COMPRESSOR & EFFECT PROCESSOR! – Is this true ???..I don’t think so, please tell me if it’s true or not !

Depends on the keyboard, a original Fender Rhodes would have to go through a line-driver to have the right impedance for the line inputs. Just like a guitar, as it has pickups much like an electric guitar has. Your Yamaha and Kong keyboards have a normal line outs and can be connected without anything in between.
Instrument inputs are often referred to as hi impedance or Hi-Z inputs, these have a built-in line-driver that matches the impedance of electric guitars and bass to the input. Modern keyboards usually don’t need that and can be connected directly to a line input.