What does this MOD knob do on this amplifier?

Question

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.

Question

What does mod stand for and what does it do? Is it a common feature?

Answer 1

Modulate something, and it changes a bit. Mod is short for modulation.

Modulation in guitar etc. effects include chorus, flange, vibrato and phase. All of which adapt the original sound, with delay and pitch changes, usually working in tandem, to produce those various effects. Distortion, overdrive, et al, are not included in 'modulation'. Neither are the effects known as reverb, echo or delay.

Answer 2

It's for modulation effects.

From the Spark User Manual, page 3:

(H) Effects Control Adjusts the amount of Modulation, Delay, and Reverb in the current preset. Use the SPARK app to change the effects type and detailed effects settings.

This is consistent with other amps.

On Fender's Mustang V.2, the MOD knob is for setting modulation effects levels.

There are two effect selection knobs on the Mustang:
• MOD — selects Modulation type effects
• DLY/REV — selects Delay and Reverb type effects (Source)

The Boss Katana series user manual indicates that the MOD knob corresponds to Chorus, Flanger, and Phaser effects.