There may be some misunderstanding about settings here if I have read the post correctly. Usually you would record with your bass volume up full, then temper the ‘Gain’ control at the Solo’s input in order to have the halo LED only ever showing green. The hotter the output of the bass, the less gain needed on the interface for it to sit happily in the green.
With regards to output issues, it’s odd that it’s distorting, if you play any audio/music from iTunes/YouTube etc, is that also distorted?
You may want to run through some Windows optimization such as in this article:
https://support.focusrite.com/hc/en-gb/articles/207355205-Optimising-your-PC-for-Audio-on-Windows-10
If you’re continuing to experience problems, you’re best to contact our tech support teams via here:
https://support.focusrite.com/hc/en-gb/requests/new
Usually it’s a small setup issue and they’ll have you up and working straight away, however there are some rare occasions where a hardware fault is present, which will simply mean you’ll be sent a new unit.
Cheers
Si // Focusrite