Stalking the Wild Mouse

Copyright 1999 R.G. Keen All Rights Reserved. Permission refused for local copies or posting from sites other than without written permission.

The Kit
Building the board
Building the box
How does it sound?
Overall Impressions

I saw the article on building "The Wild Mouse" by Steve Daniels in the September issue of Electronics Now, and it looked very interesting. I've been a sucker for wah and phase related effects for a long time, and this was an interesting variant on wahs in general, so I thought I'd build one.

My life is full enough of building circuit boards and too full of perfboarding circuits when there's a kit available, so it was the kit for me. The kit from Small Bear Electronics was shipped and arrived promptly.

Kit, cat and Kaboodle

When I opened the shipping box, I was pleased to see that the kit was quite professionally done. The parts were all contained in the heavy-duty cast aluminum box that was included as part of the kit. The circuit board was commercially produced, with silk-screened legends, solder mask and tin-lead plating for easy solderability. All the parts were first class items, no scrimping on component quality. A quick check on the worst bugaboo of effects kits showed that all the parts fit perfectly mechanically, just dropping into the holes on the board. Very neat job of doing the board layout - and I'm not that easy to impress in that area.

The kit also included a complete reprint of the magazine article and a sheet of additional instructions pertinent to the kit itself, very complete and useful documentation.

Building the Board

Putting it together was a snap. When I do a kit, I always take a while to look things over for mechanical fit before I start soldering. It's hard to keep from plopping parts into the board and soldering away, but I followed my usual rules:

The board went together with not a single hitch. The only difficulty I had was that stripping the included hookup wires was a bit tricky, as they were fairly small. On the other hand, the kit *did* include hookup wire, already cut to appropriate lengths, which is a nice touch you don't always see. Overall, I spent maybe 15 minutes installing parts into the board. The board worked perfectly the first time I powered it up. On the bench, the Wild Mouse performed exactly like its description in the article.

Building the Box

Now the hard part - completing the box. The box included with the kit is a rugged die cast aluminum unit, and is exactly the kind of thing you need for on-stage use. The aluminum is easy to work (for a metal, anyway) and should produce good results. Since I had drawn my tracing of the PCB, I could decide ahead of time where things went and do the cutting and drilling to get it all correct.

I'm going to spend more time on how to drill and fit the box on this one, not because the box was hard to fit, but because this particular effect requires more thinking ahead about cutting and drilling than some other effects. It mounts one control and both of the footswitches on the board itself, which makes for a vastly easier wiring setup, but does require that the machining of the box itself match the board very closely.

In deciding how I should drill the box, I wanted to get the buttons for the footswitch as close to centered on the long axis of the box as possible, and as nearly equidistant from the center of the box as possible, very much like the illustrations in the article. I had marked the locations of the centers of the two footswitch modules on the board tracing, so I could use the tracing as a "test board". I drew the outline of the deep part of the box on to another sheet of typing paper, and then checked to see that the lid had the same outline, which it did, very closely. Onto this box outline, I drew centerlines of both the long and short dimensions.

Then I marked off the distances inside the outline that the board would have to fit from the ends and sides because of interior ribs and screw mounting inclusions. With that done, I adjusted the two switch centers to be where I wanted them. With the board in this position, it was too close to one side, but was almost centered. I decided that I would just center the board on the box centerline; the switches came out a bit to one side of center, but close enough. With the board tracing positioned for the footswitches to be correct, I then traced the mounting hole outlines and footswitch centers onto the box tracing, and now had a drilling guide.

I marked the centerlines on the box lid (which is where the board mounting screws go, and cut small holes in the box tracing/drilling guide on the centerlines near the box edges. These let me align the tracing centerlines with the centerlines marked on the box lid, carefully making sure that the tracing was flipped the right way to be drilling from the outside of the lid. I could then centerpunch directly through the tracing to locate the mounting hole locations.

Similarly, I drew centerlines on the top of the box itself, and aligned the tracing through the holes so I could centerpunch locations for drilling the footswitch holes. Drill the footswitch holes then line up and mark the location of R10's shaft, transferring the location down the side of the box with a mechanic's square. Locate the height of the hole by measurement, as this does not have to be as precise as the footswitches. Drill a slightly larger hole than needed and just let the shaft protrude through the side, not bothering to screw down the bushing to the box. The shaft just sticks through, and the knob covers up the fact that the pot isn't tied to the box. Once you have the board mounted in the box, mark R10's shaft at a length that lets you cut the shaft off at a length proper for mounting the knob. I find that chucking up shafts in a vice and using a hacksaw is the easiest way to cut them to length. The stresses are all on the part that is cut away.

All this mechanical alignment makes sure that the board, lid, and box are lined up correctly and that the footswitches wind up where you want them. The instructions for how to make the actuators for the footswitches are very clear in the article, and I don't think any reasonably handy DIY'er would have a lot of trouble with it. Just take your time and get it all fitting right before using epoxy.

The footswitches are a novel way around the cost of stomp switches. This box needs two, and that could be very expensive. Of course, if you prefer the standard stomp switches to the mechanical alignment, you can use the standard DPDT switches as well.

The finished mechanical arrangement for the Wild Mouse looks to be very stage-worthy.

But- how does it SOUND?

It's an interesting effect. The author, Steve Daniels, is right on the money about the possibilities. With just the "resonance" control, R10, it makes for a very flexible tone control, and you can dead-on nail some sounds that are usually difficult to find. I found myself plucking out the riff to the Beatles' "Day Tripper" within a few seconds of hooking it up. In that respect, it's a lot like an updated and more flexible version of the old Vox Mid Range Boost effect on some Vox Amps. The frequency select switch works the same way as the MRB 1, 2, 3 settings on old Super Beatle amplifiers, but is has more flexibility in both frequency and resonance.

If you give it enough output level, enough internal resonance (R2), or put a distortion after it, you get some neat resonant distortion sounds as the resonant frequency and its harmonics distort long before the rest of the notes, and you get a Hendrix-ey or Billy Gibbons-esque (yeah, yeah, I know they're different, it's hard to describe) effect where certain notes or their harmonics bang the distortion harder than the rest, and stand out from the rest as more distorted. Playing technique counts for a lot here, as you can get some really sweet sounds if you have a good hand on the distortion level and are hitting notes in the resonances for emphasis in playing.

The "wah" sound is not the same as the standard old Crybaby-style wah, but is a kind of variable resonance sound that is close. By bench testing, the resonant peak does not move up or down in frequency as you change the resonance knob setting, but it sounds like it does. It includes some gnarly phase shifting as sounds go through the resonance. It's a distinctive effect, and one that does not duplicate things already out there. I liked it!

I didn't have a good way to exercise the more esoteric ways of using the pedal that Steve mentions in the article, such as driving the resonance with a rocker pedal or an LDR from a function generator, so I had to simulate these by hitting a note and then using one hand to diddle the R10 resonance knob. This worked well enough for me to hope that Steve comes through with some of the promised extensions and additions for the Wild Mouse he mentions in the article. An envelope controlled resonance, a LFO driven resonance, and maybe a linkup between two or three of these things would be a really kinky sound.

I discovered an undocumented feature of the pedal. The kit comes with a six position switch and only needs four of the six. When I turned it past the four active positions, it became a flat boost pedal. The boost was at a lower level than the signal at resonance, but could be set to be any level compared to the bypassed signal level. Neat freebee!

Overall Impressions

So - overall, is it worth the money and time? YES! It's a neat effect, not a duplicate of anything, but closest to a sweepable version of the old Vox Midrange Booster. It nails some vintage sounds, and lets you tinker others unlike you've probably heard. The board at $6.00 is a great deal - he must have bought a zillion to get the price down that low - and the whole kit, which includes a die cast box and true bypass footswitching circuitry inside it is only $31.25. I think it's a great value for some good sound.

If you missed the September issue of Electronics Now and are interested, you can contact Small Bear Electronics at

Small Bear Electronics LLC
123 Seventh Ave, Suite 156
Brooklyn NY 11215

or you can reach the author Steve Daniels by email at