I've been looking at adverts for this practice amp and also YouTube reviews. They all mention the mod facility but no-one actually says what it does.
Here's what the blurb says:
With bass, mid and treble tone stack controls, plus handy mod, delay and reverb effects, tone starter preset programs, a built-in tuner, tap tempo and more.
And here's what it looks like.
The only thing I can think of is that it means modulation, however there are several meanings for that word. For example it can refer to changing key.
What does mod stand for and what does it do? Is it a common feature?