Schaller Bow Wow / Yoy Yoy Wah Pedal - Technical Data

Created 3/14/14
Updated 3/16/14
By Paul Marossy



This is a German made wah pedal that I formerly knew very little about, and have seldom seen used by guitarists. Once in a while I see one come up for sale on ebay, and from what I can tell by researching online, there were at least three different versions (maybe four) - one being a straight wah pedal called Bow Wow / Yoy Yoy with rounded cast shell, a second version with same functions that had a square-ish cast enlcosure and a third one that was called a Bow Wow / Yoy Yoy with volume pedal function and a plastic shell. There was also a fuzz-wah pedal using the original rounded cast shell design and a second version that used the square-ish cast enclosure. I believe that the version I am showing on this webpage is the original version of the Bow Wow / Yoy Yoy, but I am not sure of the exact date of manufacture however.

I have seen some people claim that they had one of these wah pedals from as early as 1966 but I have my doubts about that. If this were the case, that would mean that they would have copied and applied their modifications to the CryBaby and/or Maestro Boomerang circuit and created their own unique shell design virtually the same day those two wah pedals were released into the world, unless all three companies were on a parallel path to create the world's first wah pedal. Or it might also mean that Schaller made the world's first wah pedal and it's the other companies that copied them and there is a cover up going on or it's simply lost to history who was really first (which I don't think is likely). I don't know but I am sure going to try and get to the bottom of this one.

In any case, below are some details about this particular example that I have.

Here is the overall pedal. The first thing that you'll notice is that there is no rubber on the treadle, the ridges are cast into it and the whole thing appears to be painted with some sort of dull silver Hammerite type paint. I'm not sure what the shell is made of, but it appears to me to be zinc or maybe a zinc alloy (if such a thing exists). Physically it is much smaller than the Maestro Boomerang and about the same size and weight as a CryBaby wah pedal. It feels much smaller under your foot than either of the aforementioned wah pedals.

On the toe end of the pedal there is a SPST toggle switch that selects between "bow wow" and "yoy yoy" modes. The switch was made by Marquardt.

Here is the inside of the pedal. The layout and design of the pedal seems to be well thought out for the conventions of the time. One quirky thing about this pedal is that it has two input jacks and the output is simply a short cord soldered directly to the bypass switch with a 1/4" male plug at the other end.

Here is top side of the PCB. The transistors used in this pedal are BC109Bs.

The two inductors are rather physically small when compared to inductors used in other types of wah pedals. Measured in place, the one on the left measures 1.69H and the one on the right measures 345mH.

Here is the underside of the PCB. Typical design for the time period it's from. Notice it simply says "Schaller Wah-Wau".

The pot, made by ESA, is mounted in an interesting way. Instead of using an intricate casting with some amount of machining like what is used in other designs, they simply used a brass mounting bracket attached to the casting with a couple of screws. There is a place in the casting where a pot could be mounted in a similar fashion to the Maestro Boomering but the toggle switch occupies the space where a pot could be mounted.

Here the pot mounting bracket has been removed. The gear on the pot is also made of brass and has a small set screw. The pinion attached to the treadle is made of plastic.

Here is an example of the type of pot used in these pedals. My understanding is that these are 100K reverse log pots.

Different view of the pot. Kind of odd construction compared to the pots used today.

Here is the bypass switch, which is a really odd design I have never seen before. It's also made by Marquardt (Italian made Vox wahs will often have switches made by this manufacturer as well). From the markings on it, it would appear to me the switch was manufactured in the fourth week of 1971. Seems about right but I need to do a little more research on when these pedals were first introduced.

Here is how the bypass switch is wired. The switch is apparently a four pole double throw oddity which is wired to be true bypass.

Since I got this pedal I have modified the output scheme. I really did not like the output cord arrangement so I rewired one of the input jacks to be an output jack instead. It can be easily reversed in five minutes to make it like original, so it's not anything I felt bad about doing.

One complaint that I have heard from people about this pedal is that the yoy yoy mode isn't that exciting, especially when you have distortion in the mix. And it's not for everyone. Where that setting really shines is with a clean sounding guitar, riding the area where you get the most treble which requires very small movements of your foot (although the lower notes on the E, A & D strings can get a cool sound also with larger movements of your foot). All it requires is learning how to work it to get those cool sounds, which is not hard at all. I really like it, it's a not so obvious wah sound that sounds a little different and does not have any harsh peaks like a regular wah pedal might. I enjoy it. If I had to compare the yoy yoy setting to something I'd say that it sounds something like a foot controlled phaser.

If you have some definitive information on the history of these pedals or corrections to the information that I have provided, please send me an email.

Original Catalog Pages

Bow Wow / Yoy Yoy Original PDF Layout

Bow Wow / Yoy Yoy Schematic

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