The look of it is striking and distinctive. The steeply inclined treadle returns to heel down position via a stout coil spring and switches off automatically via a very commonly used and easily obtainable microswitch.

Here is the front of it. Note that you have to manually turn off the power. It does not use the switching input jack scheme that most of us are accustomed to. Note that the input & output jacks are opposite of convention today, where the input is on the right and the output is on the left. The Maestro Boomerang is also quirky in this respect.

With the treadle removed we can see the unusual nature of this beast. Dominating the view is the part that the treadle attaches to, which doubles as an actuator for rotating the pot in a similar fashion to how Colorsound did it.

This plate has a dual function - it controls the position of the treadle and rotates the potentiometer shaft. Pretty clever. At lower right the flapper on the micro switch can be seen. When the treadle returns to heel down position it depresses the flapper and automatically "bypasses" the signal. In a certain way, I like that concept. I prefer switching a wah on/off in the heel position, so that it isn't suddenly harsh sounding.

This is the switch in its normal resting place. Here is how it appears with the treadle towards the toe down position. The switch is held in place with two screws.

The potentiometer is also very unusual. Seems to be partly made of some sort of Bakelite type plastic. The circuit board is upside down and hiding underneath the shaft for the treadle plate assembly.

Here is the circuit removed from the enclosure. Not the most fun thing to get apart... but at least it's easier to deal with than the Univox was.

The circuit is designed around vertically mounted resistors and was made to be as compact as possible. There is a pair of NPN transistors marked as CDC1300. I am unable to find any info on those or what the equivalent transistors might be. It appears that they were manufactured by Continental Device Corporation. Or it could be Control Data Corporation? In any case, I have determined that these TO-106 package silicon transistors are equivalent to a 2N2222.

The input jack is most unusual. Not sure why they chose to use it. The output jack is a much more conventional type. The on/off switch is a DPDT slide switch. It simply breaks the positive connection to the 9V battery. The potentiometer is a 10K-B "Cosmos" RV30YN-2J with a date code indicating it was manufactured in 1969. Interestingly, the range of rotation appears to be only about 90 degrees vs. the more common 270 degrees or so.

Here is the back side of the PCB. Notice the one capacitor added in. There seems have been some changes made to the circuit at one point in time as another example I have seen had only two electrolytic capacitors on it instead of the four that are present on my unit.

This is what the bare PCB looks like. It is interesting in that where the wires connect it is like a thru hole ringlet, similar to what you might see on a certain brand of classic canvas "sneakers" where the shoestrings pass thru. Never have seen that before.

Here we can see the bare enclosure. There are two stand-offs for the PCB to be mounted to. The box inside is the battery compartment. It's basically just a rather light gage steel stamping which was folded into the final shape with a few parts spot welded on.

This is the actuator which rotates the pot via a linkage that essentially creates a slot for that pin to move in. It's very similar in principle to the method Colorsound used in their wah pedals.

Here you can see the linkage in situ. It is held in place by a screw. The position of the pot in relation to the linkage can set using the small hole in the side of the enclosure.

Hiding under this nifty "door" is the compartment for the 9V battery. According to few bits of the owner's manual that I could find, the battery should last around 100 hours.