Turkey Day SHOOTOUT Competition

[haveyouseenhim]

Video, docs and stuff to follow next week sometime.

But I want them NOOOOWWW

[Vallhagen]

My Contest Entry; the
BLÜE MONSTER
Dual Band FET OD
Original artwork:

I asked the 9yo kid for a two-headed monster... This is what he came up with:)


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The idea behind the box:

I have, for a few months, had two ideas ... which i thought could be combineable. 1: I got inspired by Craig Andertons Quadrafuzz; the idea of frequency splitting in a stage before the OD/distortion/fuzz circuit. 2: I have fallen in love with the overdrive capabilities in the 4049UBE IC, and i wanted to build a box that really used all of that IC-s converters.

And... as this competition was announced... i thought; why not do it now... and here it is...

So... the result is: A truly High-Gain OD, with surprisingly clear separation between Lo and Hi.

**********

Credit to:
Craig Anderton, for the quadrafuzz idea in general, and especially the swept filter stage (details further down).
The guy/guys(?) at runoffgroove.com, for the Double D.  I actually use a Double Half Double D somewhere in this one.
All the helpful guys at madbeans forum, including mr Bean himself.
All you guys right here on THIS forum. I still read a lot more than i type here, but beleive me, without the information i get from here, i wouldnt have a clue about... alot:)

*********

Link to fullsize schematic:
https://dl.dropbox.com/u/10190945/Blue%20Monster/turkey/Blue%20Monster%20SCHEMATIC.png

From input to output:
First, an input buffer which also adds some gain. Then the funny part starts: The signal is split in two matched filters, LP for lowband, and HP for highband, Linkwitz-Riley style. The crossover freq is just under 200 Hz (194 to be specific), which gives about the 5th fret on the D-string. If you play in "ground position" (or what its called... your left hand down there among the common open chords...) this means that the bass strings go through the LO band, and the three higher strings through the HI band. The rolloff is 12 dB/octave though (not THAT steep), so obviously the lower E note WILL be heard through the HI band.

The next stage is a pair of full-band, phase-correcting filters. I tried a few simpler approaches (as inverting the lower band), but found no satisfaying result.

Then; OD. I played a lot with this part. I had that "obvious" idea that the lower and higher bands should have different OD circuits. BUT, for every change I made in any of the stages, it seemed as I introduced destructive interference between hi and lo. "Funny" stuff occurred. I guess that every time I change a value of a resistor or cap, I affect some RC circuit, and I introduce unwanted phaseshift.  So, I ended up with two identical OD circuits, which are heavily inspired by the Double D from runoffgroove.com.

The two OD bands meets up in a mixer stage.

Then, as the last toneshaping thing theres an active tunable two-pole LP filter. This is straight off a Craig Anderton design. FILTER_1A and FILTER_1B is a dual-ganged pot.

**


If you feel like building your own, i would be honoured:
Board Layout:
https://dl.dropbox.com/u/10190945/Blue%20Monster/turkey/Blue%20Monster%20LAYOUT.png

Etch mask (3.35 x 2.90 in, including border):
https://dl.dropbox.com/u/10190945/Blue%20Monster/turkey/Blue%20Monster%20ETCH%203350%202900.png

****

Pics:




For the enclosure, i asked the young kid for a two-headed evil monster. His original painting is the first pic in this post^^. After some digitizing i included it in the design. A funny detail is that i "knew" from the beginning that this one should be blue. I guess i allready have a green screamer, a red llama... and some yellow and grey-metallic ones.





***

Finally, how it sounds.

SOUNDCLIP:
https://dl.dropbox.com/u/10190945/Blue%20Monster/turkey/Blue_Monster_take1.mp3

 Guitar->BLÜE MONSTER->POD 2.0 (clean setting)->soundcard->DAW
...just a few riffs and tones repeated over and over with different settings on the Blüe Monster. the first 20 seconds is BLÜE MONSTER in bypass.

VIDEO:
The video is recorded with a Sony Cybershot digital camera with built in mic placed on the floor in front of a crappy practice amp. Hehe, i can say a lot about myself, but im NOT a camera man or video producer... But as "evidence" i hope its allright, and you get a hint about how it sounds.

This time: Guitar->BLÜE MONSTER->Guitar Amp

Well... there you are, i guess:) Please tell me if i missed any required info.

Cheers all!

[oldschoolanalog]

Oh yeah! 
Great presentation. From artwork to video and everything in between. 
I told y'all. It's heating up in these parts.

[haveyouseenhim]

That's great!  It's so crystal clear between the highs and lows and they kinda tickle each other to make a cool octave sound.

I'm definitely going to build this one

[Vallhagen]

That's great!  It's so crystal clear between the highs and lows and they kinda tickle each other to make a cool octave sound.

I'm definitely going to build this one

Im glad to hear that the separation quality goes through the "recording filter". In some settings, it actually feels a bit like playing an octave effect, or on two different instruments simultanously.

Very cool if you decide to build one:)

Cheers

[pakrat]

+1 on that presentation Vallhagen. Great sounding pedal and the finish on your box is really pro looking, excellent job!

[Jdansti]

Beautiful pedal, Bengt, inside and out, and it sounds great!  I heard the octave effect as well. It sounded like two instruments playing an octave apart, or like you were plucking two strings a octave apart.  You definitely hit the nail on the head with your circuit design - Very nice!  

[Vallhagen]

Thanx. Again:).

A few more details on the design, to whoever feel like building one:) :

I guess/think it can be squeezed into a BB sized box. Mine is bigger though, 146x120x38mm ("BDDD" size, bought from Banzaimusic).

The 220nF caps (Wima MKS3, the four red boxes in the upper right quadrant) i use in the build have "unusual" leg spacing; wider than your average box cap. Also (and this count as a small design mistake) named caps are a a bit too wide to fit on their space between the IC. If you look closely at the gutshot you can see that two of them close to the IC really are squeezed in. There should be no problem to adjust this in the CAD program for a "revision B", but i leave it as it is for now.

In my box, i placed 1kOhm resistors as R16 and R17.

Cheers:)

[garcho]

Bravo Bengt! +1 @ the artwork!!

[Ronan]

Very nice entry Bengt! Love the finish of the pedal, no way can I match that! Sounds good too.

[tuckster]

Üüüüüü I like thät mönstär, really nice:icon_biggrin:
Does it live under the 9yo kids bed? 

[Vallhagen]

Üüüüüü I like thät mönstär, really nice:icon_biggrin:
Does it live under the 9yo kids bed? 

Hëhë... ï häd tö täkë ä löök. Funilly enuff, i only found düsträts

/Bëngt

[haveyouseenhim]

Üüüüüü I like thät mönstär, really nice:icon_biggrin:
Does it live under the 9yo kids bed? 

[garcho]

OK dudes, here it is!

A fellow contestant was graceful enough to put up with my bellyaching, so I'll save us all the excuse-making and indignation. That being said, I hope I'm not wasting the judges' time with my terse video, lack of fidelity-conscious recording, crappy schematic, and even worse layout.
Honestly, I enjoy using what I've built and I'm proud of it, just a little embarrassed of my presentation. This pedal can go from 'stuck wah', to pheux phasor, to Leslie rotating speaker sounds, to MFOS style ray gun weirdness, to subtle blooming. I'm looking forward to tweaking further in the future, improving the PCB, and doing a full-blown build thread. I'm also planning on doing a simple op amp HP/LP version.

Folie à Deux
Dual bandpass filters with LFO controlled modulation.



I got hopelessly hooked on filters recently after spending some time noodling with Cliff Schecht's MS-20 schematic, from a thread started by Strategy and expanded by Jordan A, along with Cliff. Being a noob to this, designing a PCB for a dual LM13700 project was a little out of my league, at least if the PCB was expected to be something that would fit in anything smaller than a suitcase. So I decided to work my way up to it by making a few simpler filter circuits. The 'tunability' of a multiple feedback BP filter with a single pot seemed like a good reason to try that out first. Because the MS-20 is actually 2 filters in series, I decided to make a circuit with 2 filters, switchable between series and parallel, thanks to Rick Holt's elegant switching schematic (posted in the MS-20 thread). Of course, BP filters in series are almost painful to listen to, at least without significant post-processing, so I ended up ditching that for hard-wired parallel filters.
Each filter has it's own standard op amp LFO, with controls for rate, ramping, and depth.
There is a 'blend' knob to mix wet and dry signals, and a 'tune' knob to adjust the resonant frequency of each filter. The tunability is limited. Also, because the LFOs are controlling LEDs affecting the LDRs in parallel with the 'tune' variable resistor, the 'depth' affects the frequency, too.



 

RANDOM NOTES:
I used white LEDs for the roll-your-own vactrol because to my ears, they worked the best, and in conjunction with the display LEDs, other types did not light up both. I know there's a smarter way to wire up the indicator LEDs, but I was been pinched for noodle time.
I messed with the final op amp stage for a while, and the component values are chosen strictly by ear. Again, I'm sure there's a better way to do it, but I'm still learning the basics, so for now all I have are my ears to guide me.
I wasn't sure how to deal with the input impedance.
The power supply took some big caps to filter: 470uF and 220uF, again, chosen by ear.
Figured it's a current hog, so I didn't bother with the battery.

I whine a little bit, only play one damn chord the whole time, and leave out a few key examples of cool sounds this pedal is capable of, but I think y'all will get the idea  :

can't believe I called it a 'bypass filter', ha! 

You can see my improvised fixes for a few basic layout mistakes if you look close, but other than those, it turned out great.



Thanks to Aron and everyone on the forum, especially the veterans throwing their wisdom around for free; you're beautiful people!!!

[tuckster]

Keep on posting guys we need more of this!!!! Very nice work dudes

[Jdansti]

Great work, Gary!  I really like the name plate and it sounds great!

It's really great how this contest has spurred so many to innovate and develop new ideas and twists on established circuits.

BTW- can't believe I called it a 'bypass filter
Easy to do on video!  On my last video I called my Fender UltraChorus amp a Twin Reverb. I wish!

[garcho]

Ha! Thanks for the encouragement J! Looking forward to seeing yours and others; list of things to build has mysteriously been elongated since this contest started

[pakrat]

That is a beautiful, clean build Gary. I love the name plate and it sounds fantastic!

[pinkjimiphoton]

well done, guys, man, this is gonna be hard to judge!!!!

[Ronan]

Good one Gary! There's a lot of hardware in that little box, done well to fit it all in.

John, I too am surprised at the inventiveness of all these entries, its really good to see.