Here is a preset to test. Hook up output 2 only. Turn up the output one knob on the unit. you will hear feedback/squealing. Turn down output 1 or bypass the output one block. the feedback/squealing will stop.
Thanks for helping!
i loaded the preset and saved.
i disconnected XLR from Out 1.
i connected 2x 1/4" cables from Out 2 to my mixer 1/4" input.
i have both Out 1 and Out 2 knobs down.
i have a guitar plugged in to Input 1.
i turn up Out 2 all the way - i have a high gain guitar sound.
i mute my guitar strings.
i turn up Out 1 all the way - no change in sound, no squeal or any noise at all. Playing guitar has the same sound as before, no squealing.
is that the right reproduction procedure?
also, Out 1's level on the VU meters in the Layout>Zoom Out view is much louder than Out 2, and Out 1 is clipping when using this preset if Out 2 I/O Menu "Boost/Pad" is set to 0. if i change Out 2 Boost/Pad to 18dB, the level is just about at the Level Set line. the CPU of this preset is also pretty high, in the 85% range, and this can lead to CPU and slowness issues.
other than Out 1 clipping and high CPU, i don't see an issue with this preset, and don't hear any squealing.
i agree with Yek, that if you are using a power amp and real cab with Out 2, you generally don't send a Cab block through Out 2 to a real cab.