I have a Focusrite solo hooked up to my guitar. I managed to get sound from it in my headphones. However It sounds like some weird reverb. The sound get a bit louder and then goes completely away and then louder and then completely away, ... I have now idea where this behavior comes from.
I am using Jack and guitarix. The reverb is not an effect! If I am not providing enough information, please ask. Also note pulseaudio is killed and I get no sound other then my guitar.
Focusrite Solo Interface has a direct monitor switch. When switch is set to 'on' audio inputs to interface are connected direct to interface outputs. This allows input to be heard with no additional delay due to interface/pc
suspect you have monitor switch 'on' so guitar with no effects or delay plus the delayed audio from guitarix, both connected to headphones. the two audio streams combined can create the same effect as a flanger/phaser/reverb/echo (depending on amount of system latency)
set monitor switch to 'Off' and only the one correct audio stream from guitarix should ba audible