Question: Problem or Confusion?

In expert mode with volume pedal in feedback jack.

Example situation: I would record a 1 second loop of an 'A'

Then I would overdub a C# preparing to solo over this.

The book says that the pedal controls feedback of playing

while the knob controls feedback of overdub.

I take this to mean that if I 'Toe-up' some on the pedal,

that my playing licks will fade/decay while the overdub material

keeps going at 100%.

But what happens is that the looped stuff fades away.

Is this problem or just confusion.

What I want is to have static layers going contiuously

while my playing licks repeat a few times then fade.

Do I need a 2nd EDP ?

Other modes have their weirdness with pedal in feedback jack.