Turkey Day SHOOTOUT Competition

[Jdansti]

Remember, there is NO deadline for submissions. Now that we know the competition is a GO, you can submit ANY TIME YOU WANT. Just be sure to post the required submission HERE FIRST. 

HERE WE GO AGAIN!!

- The DEADLINE for complete submissions will be 23:59 on Thanksgiving Day (November 22nd 2012). You can submit your entry as early as you like. Just remember to make sure it is COMPLETE and according to the rules set forth above.

I think I know what you meant, but could you splain this, Lucy?   

[Govmnt_Lacky]

OK... let me clarify....

If you are a contestant in the competition, you can enter/post your submission at ANY TIME BEFORE the end of the competition at 23:59 on November 22nd. Basically, you dont have to wait until the last day to submit your entry.

If you are done now, and you don't want to wait ...you can submit. Some other contestants have said they wont be available around the time the contest ends. I just want them to know that if they are done or will be done soon, they can submit it.

Good luck to all and remember.... there is still plenty of time to enter. 

[Govmnt_Lacky]

To FURTHER clarify...

Competition entries will be accepted up to but no later than the competition end time/date.

So if you really want to put pressure on yourself..... Pay your fee AND start a build on November 22nd as soon as you get up 

Good Luck to all who enter 

[midwayfair]

This is a story before the pictures.

A few weeks ago, I had counted up my all my pedal builds and realized that I would very soon hit #50. I knew I wanted to do something special, and the Turkey Day competition gave me added incentive to go beyond just soldering up a complicated project -- I considered doing a Deluxe Memory Man, which is my ultimate goal for the year -- and create something at least somewhat new.

The first pedal I ever tried to build was a Tremulus Lune. I'm not sure exactly why ... I knew almost nothing, though I did at least have a lead on finding parts (Smallbear!), and simply looked up a layout online. It was veroboard, and I'd never seen the stuff, so I tried faking it on perfboard. It didn't work of course (the remnants are still in my box of fail), and I also had no idea how to troubleshoot and my only tool to do so was an analog multimeter. That was in January ... I think I've learned quite a bit since then, mostly by building or breadboarding almost everything I could find and reading everything I could find about the effects as I made them. I still have a ways to go ... I haven't touched bucket brigade technology, and there are bits of filtering that are something of a mystery to me. Anyway, tremolos are still one of my favorite circuits to build. And since this was a milestone of sorts for me, I knew I wanted something with an LFO. So I started breadboarding some things, like a fuzz trem and some other weird stuff. But just making another tremolo didn't seem like anything special, especially after I realized it would be a contest entry.

Then I remembered RG Keen's "Vibromatic," which is an envelope circuit that kills the LFO of an EA Tremolo. That seemed promising. Then the next day, one of the forum members, HaveYouSeenHim, brought up the Magnavibe and sent a vero layout. I'd worked with another design descended from the Warbletron recently, Madbean's Quadrovibe, and remembered that it was easily converted to a tremolo design. I liked the sound of the Magnavibe on its own (it's a little milder than a univibe sound, really the kind of vibe I like), but there were some issues with the tremolo mode that I wanted to improve. So I decided to pair something similar to the Magnavibe with the Vibramatic.

These were my goals with what I created:
1) Since the circuit was descended from familiar DIY circuitry, I wanted it to be accessible to other DIYers. So no unobtanium parts. So no weird resistor or cap values -- just the stuff that most people will have in their bin.
2) No parts matching, biasing issues, etc. For the most part I succeeded in this one.
3) The circuit had to be as simple as possible while still sounding good.
4) Whatever I created had to be easily used in a live situation. So anything with 10 knobs and switches was out.

Here's what I ended up with:

PDF here: https://dl.dropbox.com/u/9878279/Jon%20Patton%27s%20layouts/Nonmini%20builds/Blue%20warbler%20vibe%20schematic%201.2.pdf

Here's what it sounds like:

[EDIT 10/14/12: Published the annotations to the video.]

What's going on here

The audio path
This is very, very close to the Magnavibe's dry path, with the following changes: The gain has been increased to accommodate the signal split into the envelope circuitry, and the output caps have been changed to provide a slightly different voicing. The end result is pretty similar to the original, but there's more high end content remaining in Vibe mode and the warble is just a little different. The tremolo switch moves one of the LDR's legs from the buffered output to a series resistance between the two caps. This prevents any volume change between modes (except in the furthest CCW depth settings) and also prevents a really loud POP when switching over, which is an improvement over simply grounding the LDR, which is how I've seen it done in some other circuits related to the Wobbletron.

The volume trimmer will be set near max but was included to accommodate transistor gain variances.

The LFO

The LFO is, again, lifted from the Magnavibe, but that's just basically the LFO from the EA Tremolo with a different variable resistance element. I chose a BC547B/C because it softened the wave. It still gets plenty of wobble but sounds more natural on the tremolo setting. I added a series LED, swapped out the needlessly complicated "12K" depth and rate pots (25K with a parallel resistor) for more common values (increasing the rate pot value to ensure access to some slower settings). The LFO section is also electronically isolated from the audio path.

The Envelope

Although I started with RG's envelope, I went through a few more types of envelope circuits (the Nurse Quacky's, the Meatball's, and I even tried a couple compressor envelope/rectifier circuits, but they didn't work at all) and ended up with one that uses bits of some of them but looks and behaves a little differently from all of them. Specifically, this envelope circuit solved a few issues that others had in this specific circuit, like OP amp distortion/transistor sound from the input signal and some finickyness with the envelope actually triggering and altering the LFO. Some just killed the LFO in all settings. I also note that this one is mostly backwards ... the references voltages are in weird places. The transistor is a FET and is turned around backwards. 2N3904, the transistor in RG's envelope and the Nurse Quacky, didn't work; 2N5457 had the only completely reliable results, with all 30 I had on hand working as desired. And the LEDs are asymmetrical rather than matched like in some circuits (e.g. Nurse Quacky). I guess what I'm trying to say is, this is probably the only piece of circuitry I've ever used that might actually be unique, but who knows if it can be used in anything else. In any case, I'm very grateful to the people mentioned above for sharing their ideas and providing a starting framework.

The decay control should be set between ~10K and 50k. Lower settings may provide distortion. I believe it's actually the LEDs clipping, which is weird. My stock setting is 33K, which seems to provide the best balance and variety at any given sense setting, though hotter pickups may require a lower value. The 22nF cap was a good size to avoid too much rippling. (Credit goes to Mark Hammer for making this suggestion for the Nurse Quacky, and to Runoff Groove for noting this in their build doc.)

Note that there is no minimum setting on the Sensitivity control. This was done because some cool things can happen at both extremes, like the CW extreme killing the LFO except when playing, and the CCW extreme killing both the envelope and LFO. See the video for examples.

So after that novel, here's my official contest entry, the Blue Warbler Envelope Vibrato.





IT'S NOT A 1590A! SOUND THE ALARM! CALL THE GUARDS! FIND A PSYCHIATRIST! No, actually, remember rule #1 above? Most DIYers don't want anything to do with 1590As, so I decided to make it a comfortable fit for a 1590B. Here's the layout.

PDF: https://dl.dropbox.com/u/9878279/Jon%20Patton%27s%20layouts/Nonmini%20builds/Blue%20warbler%20vibe%201.2.pdf

But, come on ... you know I had to. Here's the 1590A layout. (The only changes are no electronics isolation between the envelope, audio, and LFO circuits, but I didn't get any ticking even on the breadboard with no filtering at all.)

PDF: https://dl.dropbox.com/u/9878279/Jon%20Patton%27s%20layouts/Blue%20warbler%20mini%20layout%201.2.pdf

I was going to build this for my second entry fee (not as an extra entry, just for fun), but I got impatient. Rest assured, it will be soldered and boxed in the not too distant future.

Additional inspiration provided by: John Lyons (for his matching circuit boards). Additional thanks to Joshua McClarren (Gtr2/1776 Effects), who provided some insight and comments into curing the op-amp distortion issues. Hopefully I've provided adequate credit here, above, and in the schematic, but if anyone thinks I left out their contribution, please tell me.

And for good measure: total cost to build this was under $25.

DIYLC files are available upon request.

[haveyouseenhim]

That's great Jon.    A winner for sure. It puts my dinky lil project to shame

[Ronan]

Thats insanely good! Sounds great! I didn't know such things existed, envelope-controlled vibra magna tremolo things.
Well done, and nice simple good-sounding circuit!

[Jdansti]

Holy guacamole, Jon!  You've somehow out done yourself!  Thanks for setting the bar so high for the rest of us!!! 

[samhay]

Wow. Very nice job Jon.

[digi2t]

Nice "shot across the bow" to get things rolling Jon. That's what I call a contender. Having that well stocked liquor cabinet in the background really help hold my attention too. Nice touch.  

Might I add that all entrants might want to use this post, and your video, as a possible template. Very well executed. I came away fully content that I had a good grasp on the capabilities, as well as the sound, of this pedal. In my mind's ear, I could hear it's possible influence in my own rig. Bravo.

Well people... time for someone else to step up now, and lay one on the chin.

EDIT - That envelope effect exists in the Ring Stinger, in Octave/LFO mode. The octave comes through on the initial attack, and then the LFO comes in through the back door. Your effect has the advantage of having hands-on control of the envelope, whereas the Ring Stinger is fixed with a trimmer. Bonus points.

[tuckster]

Chapeau!
That's a very nice entry!!

[pakrat]

Wow, shakin in me boots.... beautiful entry Jon!

[midwayfair]

Thanks for all the compliments, folks. As proud as I am of my entry, this sort of contest is the kind where I will cheer for everyone else to enter something even cooler! 

[Jdansti]

You're a good guy, Jon, and I'm certain that there will be stiff competition from the others.  These contests drive us to try new and daring twists and ideas as you have already demonstrated.

[pinkjimiphoton]

WOW.
i just watched this twice.

well done, jon...and one hell of a big pair of shoes to fill already!!

[Govmnt_Lacky]

Sadly... I cannot YouTube here at work 

Gonna have to see it tomorrow.

Can't wait after seeing the thread reviews 

[deadastronaut]

@jon:  thats a cool use of an envelope....nice work man!!!..

[Vallhagen]

Thanks for all the compliments, folks. As proud as I am of my entry, this sort of contest is the kind where I will cheer for everyone else to enter something even cooler! 

A great build you have there, Jon! I'm impressed. Sounds great (useful, really), and looks beautiful.

****

Something is actually going on here too. Maybe i WILL be ready in time. To continue the theme of teeezzahs:





Cheers folks!

[pinkjimiphoton]

this is gonna be one heck of a competition, methinks...

man...breadboards.

i have one, i never use it...never seem to be able to get anything to fly on it...do it on vero, suddenly it works.
oy...

makes my head hurt!!

[midwayfair]

Something is actually going on here too. Maybe i WILL be ready in time. To continue the theme of teeezzahs:

IIIINTERESTING! I'll keep my speculation to myself, but seeing what's NOT on the breadboard had me rethinking my initial thoughts from the schematic section. Can't wait to see it!

[Vallhagen]

... but seeing what's NOT on the breadboard had me rethinking my initial thoughts from the schematic section. Can't wait to see it!

Well, as the picture was taken, the board was actually only 2/3 populated, so who knows, you maybe were right after all. Even though i cant tell;)

As i type exactly now, the board IS fully populated though ... and it is working! Heureka! And yes, i think i will box it just as it is. Back to the computer ... PCB design... Im glad there are some weeks til deadline. The circuit is (maybe too) ambitious for my EAGLE skills.

Cheers.