Digitech Whammy Modification
HAVE A WH-4 AND WANT YOUR TONE BACK?
THEN THIS IS THE PAGE FOR YOU!
It appears digitech is finally making a new whammy pedal that’s true-bypass, as well as having mono (ie: glitchy) and polyphonic (like the EHX POG) modes. That coupled with the fact that some people have experienced problems with this mod (I never did), I recommend just buying one of the new ones when they come out.
I’m leaving this page up as it’s still a fun mod to do, and you can do things with the momentary switch that you can’t do with any other whammy.
Here is a demo of what a modified whammy can do (in addition to having crystal clear bypassed tone).
BELOW IS A COMPLETE WALK-THROUGH ON HOW TO TAKE YOUR WHAMMY PEDAL FROM ZERO TO HERO IN JUST 10 EASY STEPS.
Like everyone else, your whammy starts off like this:
BEFORE WE START, GATHER UP THE FOLLOWING SUPPLIES:
-Phillips Head Screwdriver
-7/64″ Allen Key
-Few feet of hook-up cable
-Drill with a unibit, or appropriately sized bits
-3PDT switch of your choice (I used a blue one from Pedal Parts Plus)
-SPST micro momentary switch (part# 275-1571 from Radio Shack)
-2PDT momentary (only if your doing the momentary mod).
-LED/Bezel of your choice
-1k Resistor for the LED
Removing the allen screws. You’ll need a 7/64″ key, or a plier (if you don’t mind scratching the screws up).
Remove the phillips screws holding the MIDI jack in place.
Opening it up. Be careful not to force anything during this step as you could damage the pedal.
The enclosure is in two parts, the baseplate, and the faceplate. You want to gently move the faceplate towards the right (the side with the MIDI jack), and it should push back away from the faceplate. Then push the baseplate towards the left (sliding it off the output jacks) and it should come clean off.
Here is a video showing you how to open the pedal up:
Remove the momentary switch that serves as the current bypass. We will be moving it to the back of the enclosure (using a smaller switch). Also unsolder the cables leading to it, to make the rest of the modification easier (no momentary switch flopping around everywhere).
Put the 3PDT in its place.
Cut the output trace. There’s a tiny, thin trace between the two little blobs of solder that you need to cut. Use an X-acto, or utility knife. If you have a Multi-Meter, test for continuity. You can do it without it, but it would be harder to trouble-shoot if not working right.
Cut the input trace. This one is easier to cut.
Wire it up! Standard true-bypass wiring. To solder to the tiny blobs, I loaded the blobs with some extra solder before trying to solder the wire to it.
Powering the LED. Since the WH-4 runs off AC power, we can’t just tap into the power where it comes into the board. After some poking around, I found some 5V DC power where marked on the board. The negative can be taken from a variety of places. I used the one marked on the board. I found a 1k resistor in series with the LED worked perfectly.
We still nee to be able to access the original momentary switch to calibrate the pedal. Solder the black/white cables to a momentary SPST switch of your choice. I used a Radioshack 275-1571 for mine. You can mount this switch anywhere you want. I mounted mine on the rear of the unit so it’s not visually distracting. I reinforced the soldered joints with duct tape as the black/white cables are rather delicate and felt like they would break if bent too much.
Everything mounted and ready to close. Notice the paper, to prevent shorting out with the new, fatter, circuit board area.
To put it back together, follow steps 1-3 in reverse. Here it is all put back together.
Mine has the extra 2PDT momentary, for quick stabs. The wiring is identical to the 3PDT, and you just wire them in series (one after the other). Although there is circuit board under the word ‘Whammy’ on the front, there is a small spot where there is enough clearance for a switch.
An added perk of the momentary switch, is when you have the effect engaged via the 3DPT, if you press the momentary switch you get a 50/50 blend of dry/wet in certain settings! So you can get some sounds this way that you can’t get normally.
The instructions on this page serve only as a guide. I take no responsibility if you break your pedal, or hurt yourself. SO BE CAREFUL!!
I found my modded WH-4 sounded excellent. Clean bypassed tone, and no noise or anything. This has been the case for people I have modded the pedal for, and many people who have contacted me after modding the pedal.
There have been a small amount of people that have experienced some slight noise problems after modification. This may be due to their setup, or any of other reasons.
I no longer own a WH-4 after finding a WH-1 (click here for comparison between the two!), so I can’t further test/troubleshoot things other than what I already know.
If you are hesitant to take on the mod yourself, you can contact Molten Voltage as they do this (and many other mods).