If you are using a Piezo/Microphone combination pickup such as the K&K Trinity Pro, L.R. Baggs LYRIC, or others, you may find yourself having some problems with High-Gain effects like Overdrive and AutoWah on your ToneWoodAmp.
This is something we are working to correct, but for now, we have a temporary workaround.
First, you will need to Set the Notch Filter using a standard effect like Reverb or Delay and take a note of the Notch Filter settings you use.
With this complete, access the Global Settings menu by combo-clicking the Effects and Parameters knobs, and turn the effects knob until you see the option for guitar.
Select one of the five guitar banks you have not used yet, and set the Notch Filter settings as you had previously.
Now that the hard part is over, slowly reduce your master gain until feedback stops.
It is important to note that you are assigning a secondary bank for one guitar. When changing back to other effects ( reverb, delay, leslie, tremolo), you will want to go back to Master Settings> Guitar and select your primary bank.