Sometimes you get some weird stuff in. From the title I couldn’t even fathom what this pedal should be doing. Also internet isn’t finding any. Lets dig in!

The circuit
This pedal came in a HUGE box (very small PCB) with five controls and a single PSU input (DIN plug). My friend found this pedal quickly in the Elektuur (a Dutch magazine on all electronic equipment). All issues can be downloaded here. This pedal can be found under the title ‘Vervormer’ in the February edition of 1979. The print of this pedal can be found in the October edition of 1979 and is called ‘Vervormer op print’.
For the non-Dutch readers: it is a standalone dirt pedal that takes clipping to the next level. The pedal was designed to alter the clipping of the upper and lower part of the input wave independently by adjusting the character of the clipping (called ‘Attack’: hard clipping or soft clipping) and the amount of clipping (called ‘Crest level’). It is fed with a bipolar PSU but in the articles a version with is also available with only a single 9V power supply.

I traced the pedal:

The fix and the mods
This pedal came in not working correctly. The former builder mistook one potmeter for a wrong value and kinda messed up. With the original schematic and my own schematic I could easily trace the problem. In the end I replaced all potmeters as all potmeters were scratchy.

I ended up doing some mods on this unit:

• I replaced the PSU input to a single 9V input and added an 1044 IC to get 9V and -9V from a single power supply;
• I replaced the 10k ‘Gain’ resistor (R16 in my schematic) with a potmeter giving me a gain control. I used a 10k reverse log potmeter in series with a 100R resistor;
• I’ve added a TPDT switch and a LED.

The sound
The sound before the ‘Gain’ mod was tame and dull. All I got was a velcro like fuzz sound in the most extreme settings and anything lower would result in a clean, loud tone; no overdrive, no distortion, no clipping. In this mode I couldn’t grasp the function of the pedal.
After the mod though the unit changed into a fire breathing MONSTER. Suddenly, as far as the ears could hear, there would be clipping. Controls would alter this clipping in a very musical way and I could get some really interested sounds from this unit. Suddenly, this unit is AMAZING! What I enjoy most is that the character of the input signal is mostly unchanged and will sound through the clipping proces. Also putting other dirt pedals in front of it adds depth and character to that sound. I love it!

A standalone clipping machine! That sounds like a Fabulous Megalonoise machine!!

Links

• First article on this unit called ‘Vervormer’ in the February issue of Elektuur 1979
• An article on the ‘Vervormer’ pedal with a PCB in the October issue of Elektuur 1979