Manual page 11.

EQ settings are intentionally not reset. But it is easy/quick to set all bands to zero in the EQ graphic screen with the parameter values highlighted. By a quick turn of volume, press vol knob, quick turn, press...

I feel there is a bug with the EQ presets or at least I can't figure out why it behaves the way it does. Its hard to explain, but I'll try.

1. press EQ button
2. press encoder 2 until "press select: XXX" shows up
3. now with rotating the encoder 2 the user can scroll though EQ presets.

if for this example presets 1-3 are set by the user (different EQ curves) and presets 4-20 are empty this happens.

4a when "quickly" or at a steady pace moving the encoder the presets manual, temp, 1-3, and the empty presets 4-20 are scrolled through - works as intended and like the user would expect

4b when rotating the encoder and stopping at preset 2 (for this example) the unit switches to preset 2, now moving over to presets 4-20 will show the preset 2 EQ curve instead of an unedited one, since these presets should be "empty" / flat EQ curve.

There is a reason that it is like it is ... It shall prevent that you can too easily delete all of your customized PEQ settings which might have taken hours of time to get them right. Do you want to risk to loose all this in seconds ?!

There is an easy way to get factory settings

1. get one PEQ Preset of the 20 into neutral position (Gain to zero in all 5 bands), i.e. the 1st one.
2. save this i.e. to PEQ Preset 1 "neutral"
3. perform factory reset of the unit
4. apply PEQ Preset 1 "neutral"
5. save these settings ("factory" and PEQ Setup "1-neutral") to i.e. Setup 1 and call it i.e. "factory settings"

If you want to "nullify" other PEQ settings, load "1-neutral" and overwrite the one which you want to nullify with it.
Alternatively simply bring the Gain in all 5 bands to zero and overwrite.

If you want to "nullify" other Setups (2..9), then load the "1-factory settings" which you saved
and write it to the one which you want to nullify (2..8).