thanks Erik,
just want to close with my 20 bucks 'active D.I.' (power adapter included) (box is normally used for long cables)
gave me enough level and a balanced line input.
https://www.sweetwater.com/store/detail/TeleportGLT--tc-electronic-teleport-glt-active-guitar-signal-transmitter
thanks guys, I'm ok now.
my guitar goes into a TC Electronic GLT box, then balanced into RME AD-2 converter (input level -10) and spdif into the PCIe soundcard.
now loud/noiseless enough for me.
I never used the analog input of a PciE card before, maybe noise was mostly caused by low level, then balanced signal into unbalanced breakout cable...I don't know.
thanks for your suggestions and help !
met some people that had it, would phone a specialized hearing dept at hospital.
maybe the receptionist/assistant could -by asking you questions- rule out/confirm and hopefully help.
good luck