Polecat Dragonforce Overdrive Thingy - Wimpy Laser Etch

[culturejam]

Got my low-power laser etch test boxed up. My dimensioning was slightly off in the artwork, but close enough that it worked. Forgot to move the TONE text over when I moved the drill mark, but it's close enough for rock n roll. Accidentally shot clear *satin* over the etching, so it's sort of a semi-flat look. But it's sturdy enough for stepping on.

Got the knobs a long time ago from BLMS. Enclosure is from there as well. It looks rough around the edges because I've dropped it a few times and smudged it up, etc.

The circuit is one I've been diddling with for years. It's a two-transistor overdrive with Volume and Tone pots and a switch that engages/defeats some clipping LEDs. It started life as my first-ever original circuit and then was sold by Rej as the Temple of Giants. Since then, I've added some major tweaks. It's got the same basic vibe, but it plays a lot better with different guitars and pickups now and is a lot more flexible (previously just had Volume control). I also added a couple of ferrite beads for noise suppression (stole this idea from Spaceman) at the audio input and power input. I went SMT to save space.

It's quite possibly the most controllable gain-wise with guitar volume that I've ever played. It can go from spanky to stanky with just a change to the guitar's volume. I actually can't believe it works so well at that, especially since that was never a design goal for me. 

I had originally called this one "Bad Hombre" as a poke at our fearless leader. Then I decided to make a few minor layout changes and rename it "Polecat". But then I wanted some dragon art on this first build, so it's a whole mish-mash of ideas. 

Anyway, here are some pics. The damn 9V jack is janky, so I'll have to pull all the jacks out and replace it, but it was good enough for a quick test.

Also, I have like 100 of those footswitch PCBs, so if anybody wants a couple let me know.



Ran out of room at the top (placed the art too close to the top and the footswitch too close to the bottom) so I had to get creative on the wiring, but it works. Learned for next time.

[matmosphere]

Nice! Great build and great write up. The pedal is impeccable. And I learned something from your write up. The whole Ferrite bead thing is interesting.

Where do you get the ribbon wire btw? Looks like it would be easier to work or at the very least easier to strip.

[jubal81]

Polecat is genius. Wish I'd thought of that. Looks like fun. They BJTs?


Also, mind sharing which ferrite bead you used? I'd like to look into trying that idea.

[culturejam]

Where do you get the ribbon wire btw? Looks like it would be easier to work or at the very least easier to strip.

I think Smallbear used to have the 1.5" or 2" version, but I thought those were too long. But Mouser has 1" and they are pre-stripped: https://www.mouser.com/ProductDetail/538-25001-0601

They BJTs?

Good old 2N3904. I try to use garden-variety parts when possible.

Also, mind sharing which ferrite bead you used? I'd like to look into trying that idea.

Seriously, I have no idea if I chose the right beads. Here's the link to what I'm using: https://www.mouser.com/ProductDetail/623-2512065007Y6

As I recall, I sort of just copied the resistance value of what Spaceman was using. I did some reading on how they work and how to choose them, and then just did the best I could in picking one. I can't quite recall all the details of how I arrived at this particular bead, but there was at least *some* thought put into it.

Do they work? Well, the circuit isn't noisy. But I'm not 100% sure it would be just as quiet without them. 

[cajone5]

Any extra boards? The temple of giants was a shockingly awesome one knob fuzz. I'd love to pick up a couple of the tweaked update if you have them available.

[culturejam]

Any extra boards?

I hadn't thought of selling any, but I guess I could as there are a few extras. I have the footswitch boards, ribbon cable, and SMT parts as well. I could do a package of all that, I suppose. Send me a PM.

[cooder]

Very cool! Would you share the schematic of the circuit, I'm pretty curious about touch sensitive circuits and what you describe going from to spanky to stanky with vol pot.
If it's a commercial sensitive schematic for a product to come I totally understand if you don't want to share.
Cheers

[cajone5]

Any extra boards?

I hadn't thought of selling any, but I guess I could as there are a few extras. I have the footswitch boards, ribbon cable, and SMT parts as well. I could do a package of all that, I suppose. Send me a PM.

Email sent. Accidentally clicked the wrong link and didn't realize it until after it fired off.

[alanp]

I built a Temple of Giants, it's a pretty nice circuit already, this one must be bloody nice!

[culturejam]

Very cool! Would you share the schematic of the circuit, I'm pretty curious about touch sensitive circuits and what you describe going from to spanky to stanky with vol pot.
If it's a commercial sensitive schematic for a product to come I totally understand if you don't want to share.
Cheers

I don't see any reason to keep it a secret. I'll post it up later on today. But frankly, I'm not entirely sure why it works the way it does (the original circuit, that is). I literally sat down with a breadboard and start subbing in/out parts until it sounded "cool". This was almost 10 years ago, haha. I mean, the bias resistors make no sense to me, but I've not actually sat down and done any math to figure it all out. Maybe somebody else will take a crack.

[nzCdog]

That etch is fantastic... you gots all the toys bruh!
You had me guessing what the circuit name would be as I read on... Almost bet on Stank Spanker but Polecat is a great name.  I want to build this!

[culturejam]

Schematic and notes are posted here: http://www.madbeanpedals.com/forum/index.php?topic=28212.0

[pickdropper]

I'd actually like a board, too.

Btw, awesome name.  Destined for greatness, I suspect.

[studiodunn]

That ribbon cable hook up is epic.
And I need to up my knob game, starting with anodized aluminum. Well done.

i was actually in a band called Polecat..............flash back

[stringsthings]

I missed this when it was first posted.

Great build!  I'll check out the schematic in the the other thread.  Sounds to be worth building.