Author Topic: Funeral Wah - A Tyco Brahe Parapedal Clone Build.  (Read 589 times)


Funeral Wah - A Tyco Brahe Parapedal Clone Build.
« on: February 08, 2020, 08:04:54 PM »
EDIT: I built this a month or two ago. I was waiting to get a better handle on it before I posted a demo. I swear it's better than the last one.

So, I built a clone of the Tycobrahe Parapedal. My first rocker-wah build.

(Un)holy Iommi, this thing is awesome!

I started by breadboarding the circuit. Just to make sure I could get the circuit to work. I changed some cap values just for fun but, really, I wanted the 'stock' sound. Or as close as possible. I'm happy with it.

I used the schematic drawn by Ciaran Haslett, a negative ground version. After reading up, I added a power filtering cap on the 9V line and a Q control (25k pot replacing the 10k in the feedback path from the output of the 4th stage to the inverting input of the 2nd stage). I can tune in oscillation with the pot and control the pitch with the rocker. More noise. Cool.

I made my layout in DIYLC ( ). Turned out nice and compact. Wasn't sure how much room I would have.

It's a relatively simple build. Not many components. Spent an evening on the board. It fired up once I reflowed some joints. Assembled the rest of the hardware the next day.

I got the dual-gang 10k pot from Tayda. I got both log and linear. 16mm, knurled shaft. The kind that only has one 'barrel' for two wafers. Only comes in PCB mount type from them.
The shell and pinion, I got from Small Bear. The shell is heavy and feels and looks very solid.
The pot, on the other hand, feels like it's not gonna stand up to heavy use (it's not made for this application, I guess) and I should order a couple more (until I find a heavy duty one). Maybe find some small connectors that would fit the pins for easy, solderless, replacement... Any ideas?

I used a log taper pot in the circuit, for a slower rise of the sweep at the start. This is the part I like most. Just after the brunt of the volume swell, when it goes "bwow!" I had some work to do to get the pot fitted. The space is more than large enough for this pot size, but the thread of the pot is short and small. As I read in posts on here, I filed down the part that holds the pot so I could slip two washers on each side and still have enough thread available for the nut. I used washers I hapenned to have. About 1.5mm thick. Feels stable. The rest is simple to mount, with Steve's assembly instructions. No problems. Except for the bearing pin. It just wouldn't go in at first. Thought I'd dent the pedal, hitting it so hard... My center-punch did dig into the pin head... Wasn't going in. So, I enlarged the hole with a round file until the pin would go in but still need to be hammered in hard. I flared the hole a tiny bit. Worked well. I also had to enlarge the hole for the DC jack. I use the big plastic ones with an off-center 2.1mm hole. Or was that a hole for a stereo or expression out? Heh, you're a DC jack now.

I sprayed it a medium blue. I had a choice between that and orange. And the original is blue, so... I thought about making the rocker orange and base blue, but it looked kinda toy-ish after I mocked it up. I sprayed the coats of clear from far away so it would create a rough finish -- sort of matte. I put my blue LED under the rocker. Looks cool. I think I'm gonna make a bottom plate out of plexi-glass. Less subtle.

One last question: what is that bolt I installed under the bracket of the tension adjustment assembly? For the battery clip?

Audi Clip:

Some pictures:

"Displaying my ignorance for the whole world to teach".

"Taste can be acquired, like knowledge. What you find bitter, or can't understand, now, you might appreciate later. If you keep trying".