Please forgive the shaky cellphone footage!!
1. create a preset with no pedals or amps.
This should give you a completely dry tone
2. connect spark 40 to computer via USB
You may have to wait for your computer to finish setting up the amplifier as a sound device
3. open Bias FX 2
4. Click on settings in the top right, then click audio settings
5. select positive grid USB Audio Device as the output device. You may need to select it as the input device as well, however mine selected it automatically.
6. control volume with the tiny knob labeled "music volume" next to the headphone jack. I also use the input and output volume controls within bias FX2 to help get the right volume.
I also uploaded a preset to the tone cloud called "interface" with these instructions in the tags.
![](https://s2.save4k.ru/pic/iffT4yMsWH4/maxresdefault.jpg)