Your UCX II supports two different reference levels on the analog inputs which change the input sensitivity.
This you can read from the manual.
When switching between the two reference levels, didn't you see the change in the metering?
I would 1st start setting the gain to 0 and to look what sensitivity gives you the best starting point.
You can use the Instr Gain to fine tune the level in a 2nd step.
Do not overload the inputs, you need to stay below 0dBFS.
You can also use Autoset, if enabled it automatically lowers the input gain.
But it can't change the reference level, this has to be done by you.
Line In 3-4, front
as AD, but:
Additional digital Gain stage: 0 up to +12 dB
Maximum input level, +19 dBu, Gain 0 dB: Line +19 dBu, Inst +13 dBu
Maximum input level, +13 dBu, Gain 12 dB: Line +1 dBu, Inst -5 dBu
I am very satisfied with the quality of my Instr input on the UFX III. I would expect the Instr input on the UCX II not to be worse, although it seems to be a different circuit with a different gain range.
Here a sound sample of a Gibson Archtop (L5 CES) recorded via UFX+ or UFX III (do not remember exactly) Instrument Input. Without any virtual amp, the pure Guitar signal...
From this blog article: https://www.tonstudio-forum.de/blog/Ent … CIe-EN-DE/
Direct link of the recording: https://www.tonstudio-forum.de/attachme … -320b-mp3/
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14