SCHMORG Double Helix Parallel Drive

dawson

Well-known member
Hello!
I'm really excited to share this one with you fellow effect enthusiasts- born from four great ideas from actual circuit designers, hacked together at SCHMORG Laboratory with bubble-gum and tape, I present to you: the Double Helix

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So WTF is this big guy all about?

TLDR: It's my favorite fuzz in parallel next to my favorite overdrive- the Pedal PCB Persica and Tommy II, respectively.
Switches between:
Fuzz ON
Overdrive ON
Both ON in parallel
Buffered bypass

The little toggle on the red side allows for an external effect to be switched ON/OFF with the fuzz- or simply just hang out in front of both effects like normal.

This sort of thing has been going on in different forms without my knowledge for decades, but came to my attention recently when I saw an awesome parallel fuzz pedal over on MadBean called the Peacock, designed by forum member Aleph Null. The designer was rad enough to post a schematic of his circuit, which included a switching system that I never would have thought of. I built the Peacock, which rules, but I also built-out just the switching system so that I could audition different circuit combinations to create my own parallel drive. It looked like this:

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I found great results with all sorts of combinations of my favorite circuits, but right away, the combination of the Persica + Tommy II was on my short-list.
In a moment of greed and overambition, I built this doo-dad that would allow for any two parallel permutations between the choice of four different circuits:

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I tried all sorts of things over 10 days or so, but kept coming back to the original pair. They just sound really great together with all of my other stuff, so I sidestepped the 4-in-1 idea and committed to the Persica + Tommy II.

In my tests, I realized that the input/output buffers from the Peacock were limiting the amount of tonal range I was getting from messing with the TONE and BASS knobs on my guitar- possibly due to them being tuned to completely different circuits, I imagine.
I had another parallel circuit handy, the JMK Paralyzer, which worked great to solve the issue.
I sent the prototype GERBER to JLC..

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There were many issues to debug.
I had the power pins 4 and 7 in the wrong spots, which didn't end well for that soldier..
I swapped a TL071 for a TL072 on that strip-board to add an extra buffer because the silly effects-loop switch was making noise.
The footswitch daughter boards were goofy.. other dumb stuff too, but I got it going and was super happy with the sounds!
Back to JLC:

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So there you have it, the Double Helix!
What's so great about Parallel stacking are the transitions you get.
My main trick is to start with the thick fuzz sitting back in the mix for a verse, then adding the overdrive in, loud and clear when guitar needs to be heard for an instrumental bit.
I get the clarity of the overdrive without losing the underlying character of the fuzz that I started with.

The opposite trick of adding fuzz in beside the overdrive works really well also.

It can be heard in context by listening to this tune my bandmates and I released today:
Link: BUSTARD- Recycled Air
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Reverend Descent> Double Helix> Deflector Reverb> JMK Paralyzer (Wavelord+PhaserII)> VOX AC30

The faceplate can mount into my SCHMORG pedalboard/rack build, or all alone in a big ol' 'dummy' 1590XXX or something:
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More on that here: SCHMORG
 
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Wow dude, you nailed it with the board! I mean really everything in this build report stands out but that board is stunning!

Your track is gnar-bar 🙌
 
UNBELIEVABLE.

HE’S OUTDONE HIMSELF!

EDIT: Just now noticing the two resistors next to the ‘double helix’ text. Awesome design choice! I think I’m going to need re-read this a few more times to take it all in.

Thanks a lot @benny_profane!
I'm glad you saw those resistors 😎
I couldn't quite get the layout to be symmetrical so I did that instead.

This post is overwhelming. Why you gotta put that much cool ass shit all in one place? Save some schmọrg for the rest of us.

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Seriously though, 👏👏👏👏👏

Thanks @Mentaltossflycoon-
I know you've been dealing with a case of the parallel fever recently as well!

Damn! I like that cover art even more now.

The scanning square!

Thanks for listening @Erik S- I'm glad you dig the artwork!

Wow dude, you nailed it with the board! I mean really everything in this build report stands out but that board is stunning!

Your track is gnar-bar 🙌
That parallel drive is the coolest thing ever…

Thanks for listening @steviejr92- I'm glad you like the track and the pedal!
I'm super glad I got turned onto the whole parallel thing- sets with the band sound more balanced and I do way less footwork than before going parallel.
 
I know we keep saying MOAR SCHMORG, but I didn’t think you could. Awesome job, dude!

Thanks a lot @BuddytheReow!
*This project is super special to me, and it was only made possible due to the vast oceans of knowledge that exist on these forums- including many technical threads that you've started over the years- thank you for being an awesome resource!

What an evolution. Bravo!

Thank you @szukalski!
Some of those silk-screen patterns on the prototype may look familiar to you 😎
Thanks again for sharing all the work that went into your DipTrace library- that's another thing that this project wouldn't have been possible without!

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Very cool man! Looks killer And the song sounds great! Nicely done.

Awesome!
Thanks so much for listening to our song, @Paradox916- we really appreciate it!
 
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