My suspicion is you have the Katana cranked really high and are using the small potentiometers in your guitar to then control that enormous gain and volume.
That may leave you with much less control than desired.
Depending on the potentiometer it may be logarithmic scaled (vs linear) and it may be a bit rough at the ends (nearly off or all the way on).
They also can be dirty.
Before cleaning or replacing them, try backing the master knobs in the Katana off such that you can ride the guitar volume pot closer to mid range and see if that helps. It will give you more control anyway.
So for what it’s worth I would NOT have Master Volume on the Kat cranked all the way. I’d set it somewhere in the middle and then use gain and volume to adjust the tone as I want it. Then Master Volume just increases/decreases the overall volume for you. However I know there is much discussion on this in different forums and some follow your approach.
It doesn’t sound like the amp is your issue (but easy to prove if you have another guitar). It seems more likely an issue on the guitar pots particularly if you’ve got a crackle and then it suddenly kicks in. Again best way to prove is by trying with another amp.
If you can’t try with another amp I’d find your nearest guitar shop/luthier and take it to them. Far easier for them to fault find and do it quickly.
Agreed. I tried it because of all of the claims it sounded better, and I couldn’t hear it. And it was a PITA to use.
This is worth a watch:
It is probably worth getting a can of electrical contact cleaner and giving the pots a small squirt (from the rear) and a bit of a manipulation to work the contact cleaner in, before going to guitar shop.
I did this on a cheap bass I was restoring and it worked wonders.
Thanks for the tips everyone. I have dialled back the volume controls on the amp and that seems to have reduced the crackling. I also tried rolling the pots back and forth for a bit, which was a tip on google. I will also try the contact spray.
However the increase/decrease in volume is still a bit jumpy so if the contact spray suggestion doesn’t work its off to the guitar repairer.