Bad Horsie Contour Mods Now Available

[Transmogrifox]

I posted a schematic that details the mods pretty well for adding the contour option to the standard bad horsie:

www.geocities.com/transmogrifox/badhorsie

You must remove C14 from the circuit board and use its pads as shown on the schematic.  You put C14 in your perf board circuit. There's lots of room inside to add the circuit.

I also put a pinout of the TL074 on there for those using the quad chip.  I think since the contour circuit only uses one op amp, it is just as well to use a TL081 or at least a dual op amp.

If you have unused op amps in a package, just short the output to the (-) terminal, then connect the (+) terminal to V/2 so the chip doesn't go unstable.

If you use a TL081, this will not be a problem.  Do a google search for "TL081 datasheet".  Click on the link and follow it to the datasheet and you should be able to find the pinouts of all the single, dual, and quad packages.

[jimmy]

just out of curiosity, isnt the contour switch just a switch to add another way (twin-t style) in series, and you adjust the sweep with the 'contour' pot?

cheers
Jim

[cd]

just out of curiosity, isnt the contour switch just a switch to add another way (twin-t style) in series, and you adjust the sweep with the 'contour' pot?

Yup.  It's basically Morley's Classic Wah circuit that follows the BH circuit (which is a Vox-alike circuit).