Your Katana MKI or MKII has a built-in graphic EQ and parametric EQ, available in the BTS for KATANA MKI/MKII software editor. This enables you to shape the overall tone of an individual patch toward the end of the signal chain. This is a very useful tool to use if you find that you have a significant inconsistency between patch levels.
Once you have shaped your tone for a specific patch to your liking, using the LEVEL adjust will raise or lower the volume of your patch without affecting the tone. Once you've customized your user Channel/patch, then make sure to WRITE/save your settings to the Channel.
BOSS Tone Studio for KATANA MKII - PARAMETRIC EQ
BOSS Tone Studio for KATANA MKII - GRAPHIC EQ
BOSS Tone Studio for KATANA - PARAMETRIC EQ
BOSS Tone Studio for KATANA - GRAPHIC EQ
These parameters are available per patch and can help ensure patches are consistent in regard to their levels from patch to patch, or Channel to Channel.
Note: The MKII range has access to two separate EQs per patch, which offers further functionality and tone sculpting.