Question about TS808 boost capture volume knob

How do I know how much volume i need to dial in theTS capture to boost a preamp capture (JCM800)?
The volume knob on the TS capture makes a lot of diference when turned up or down in the overall tone.

I downloaded the TS808 captures from Tone Junkie. There are 4 different captures at different gain stages. Try those and see which works best. I had pretty good luck with those.

Just like a physical pedal, you should just tweak the knob and listen, as with most things. If you want more gain, turn the volume up, if there’s too much gain turn it down. The louder the signal going into the amp, the more distortion you will have.