DigiTech Whammy Pedal Checkout

This pedal wouldn’t work regardless of how it was connected. He tried the supplied power supply and a pedal power unit in his pedal board, with no luck.  Could the Unbrokenstring Crew straighten out this mess?

We put the pedal and the power unit (wall wart) on the bench and verified that nothing worked.

Here is the clue.  The customer provided a DC 9v output wall wart, a power standard which is commonly used in the world of guitar effects pedals.  That power standard is not compatible with this unit.

Not much else to see around the rest of the pedal.  The MIDI control is a nice touch.

This is the ‘correct’ wall wart.  This one says 9vac output, which is what this pedal needs.  I love eBay!

Something is rattling inside this unit.  Removing these Allen head cap screws will allow us to open the case.

This is what is rattling.

And here is where it goes.  This hardware works well, so we can set the switch aside for now.

The electrical connection between the circuit board ground and the chassis is made via this metal stand-off.  This connection was intermittent until we took the wire brush to the end of the stand-off.

The light spot on this circuit board is called ‘measling.’  This indicates that something got very hot.

This inductor goes between the power supply and the chassis ground of something plugged into the pedal.  So, it failed.  The head of the destruction caused the measling seen above.

Here is another view.  This inductor serves as a simple noise filter when nothing is plugged into the guitar input jack.

The inductor is replaced and the unit goes back together.  Working with the correct wall wart, this pedal is fun!  It does pitch bending and chorus effects surprisingly well, considering its age and the technology used.

Thanks for reading all the way through!

CONTACT – David Latchaw EE