DIRTY BOOTS V6

so i finally got my buddy's dirty boots finished.  it's going to be used on guitar and organ, so i added a couple extra controls.  a pre-bass and post-treble tone control combo work great together.  this is the main recipe for filtering distortion pedals, so it's no surprise.  i plan on doing a full overhaul of this design in the future, to see if i can optimize it any further, but until then, this one sounds great.  here's the schematic i ended up with.

and some gut shots.

 unfortunately i ran out of alpha pots in the values i needed, but the ones i ended up using are of decent quality.  here's a couple clips i made of the harder fuzz that this pedal can do.  the first is the DB by itself, the second is boosted. disregard the titles. it was 5:30 am when i got this thing finished last night.

FOUR HORSEMEN OVERDRIVE

well, i came up with another dirt pedal the other day.  lately, i've been experimenting with mixing different types of transistors together to achieve new tones, and this one kind of  takes that idea to the extreme.  it's designed under the premise that the stages increase in breakup as it goes along in the circuit, but instead of using stages that increase in gain, different types of transistors are used that exceedingly distort as the the circuit progresses.  for instance, the first gain stage is a silicon BJT.  this is used to get a decent push going and a very slight amount of drive.  next, is a MOSFET transistor, which like to distort a little easier, and in a bit more pleasing and richer way than the previous Si transistor.  finally, there is a germanium stage, which of course loves to distort in a very full and heavy overdrive, especially when driven by the previous gain stages.  the result is a very clear, yet complex crunch, that has a very nice character to it.  to round things out, in the beginning of the circuit is a JFET buffer, which helps to increase the current, and gives a nice high input impedance for the guitar pickup to see.  so in the end there is a total of 4 different types of transistors, each of which i tried to use to their optimum potential.  hence the name, the Four Horsemen Overdrive.

the tone control is a variation on the SWTC, but it has an added pole for a steeper rolloff.  the frequency point where the curve begins is rather high, so it is really more like a presence control- just taming the highest of frequencies, keeping the basic tone intact.

this circuit was spawned from a simpler design called the Nice Little Overdrive.  you can see the evolution in the thread over at FSB.

http://freestompboxes.org/viewtopic.php?f=28&t=11745

here is the schematic as it is in the latest version.

here is a pic of a vero layout that i built up.

and here is a quick video i made on my iphone.  the video is of the previous version without the high end rolloff presence control, and the bypass cap on the last stage, which adds a bit more gain.  the voice of the circuit is basically the same, but there is a little bit more flexibility.   of course the quality isn't the best, but you can get the idea!  ignore the man behind the camera.

DIRTY BOOTS SOUND CLIP

someone asked for a clip of the Dirty Boots, so I dug one up. HERE is a soundclick page by danielzink where you can hear it. if you go to the second song down, it's in the micro pedal demo. you'll hear a phaser first, then the DB. I haven't listened to the clip in a while, so I'm not sure how accurate of a representation it is, but I'm sure it's close. thanks, Dan!

MILITARY DIRTY BOOTS PICS

here's a Dirty Boots I built up in an old tank communication control box. it's got some serious mojo(just for fun;))components, a switch for hi and lo gain, and a single volume knob. I like the idea of repurposing death machines for rock and roll. I should've bought more of these boxes when I had the chance! I've got one more, if anyone is interested.

MONA LISA OVERDRIVE LAYOUT

i was asked to post a layout for the MLOD, so here it is.  enjoy!  i tried this circuit out with 2n5457, j201, and j309 fets.  they all work fine..  the Q2 position is where most of the magic is.  try different transistors for different tones.  i enjoyed a 2n5210 with an Hfe of 250-300 there, myself.  it had nice midrange content without sounding muddy.  the images are at 600 dpi, a current limiting resistor for the LED has been added, and the gain pot can go up to 10k  that's all you have.  this circuit is a great sounding boost/light OD/ line driver/buffer. i hope you dig it!

take it easy!

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LAYOUT IS VERIFIED.

MONA LISA OVERDRIVE

alright, here is my latest offering to the faceless electronic gods of the global interweb.  it's called the Mona Lisa Overdrive after everyone's favorite cyberpunk masterpiece, and dystopian premonition written by William Gibson.  if you haven't heard of  it, check it out!  anyway, on to the the goods- 

i thought i would build something that would turn on the guys that were into the lighter side of things- something different than my usual wall of fuzz tones.  with the MLOD, you can get a heavy boost, or a light overdrive reminiscent of vintage microphone preamps.  the fancy thing about this circuit is the lack of coupling caps in the audio path- something usually reserved for mic pres and hifi circuits.  this lends itself to the "transparent",  uncolored sound happening here.  if you encounter any oscillation at the highest gain settings, simply raise the value of the 100 ohm resistor near the gain control to lower the amount of maximum gain. 

as always, if anyone happens to put this on the breadboard, or if it sounds like something you might want to build, let me know, and i'll whip up a layout for it.

take it easy!

DIRTY BOOTS TWEAKS

jrod over at FSB is planning on building a DIRTY BOOTS, and asked me what kind of tweaks could be made.  it's really a highly variable circuit, and can be tailored to your specific tone very easily.  here's what i wrote to him-


there is a lot of tweaking that can be done to the DB.  you might want to lower the collector resistor on Q2 as it is a bit voltage starved.  if you want less drive, increase the resistor in between stages, or take out the bypass caps on the emitters.  also, you might want to increase the collector resistor on Q2 as it is kicking out pretty much full gain, and that can make it a bit noisy.  maybe try 1K.  it all depends on what you want.  if you want it brighter, lower the value of the compensation cap from C to B on Q1 or put a 47K resistor in series with the input.  adjust the in and out caps for low end.  it's a really easy circuit to tweak, so i would just put it on the breadboard, and figure out what you like for your amp.

ELEKTRATONE'S DIRTY BOOTS

FSB forumite elektratone built up this cool rust finished version of the dirty boots a while ago.  i thought it was about time he got some fame on the blog.  it definitely looks like this thing's been through the apocalypse and back!

2, NO, 3! NEW DIRTY BOOTS VEROS!

dudes! made up a few new veros for the db. the first one is a small layout for box caps and radial electros for you guys that like those little baby boxes. the second one is for axial caps vintage style and specifies the specific type of caps that i have been using for my builds. of course, sprinkle your mojo to taste. i'm callin this on v5.2 because of the added reverse polarity protection diode as well as a limiting resistor for the pre control. haven't decided at the exact value for that one, most likely around 50-100K, or just put lug one straight to ground like before. the third one is just stupid small. i call it rev2. good luck you masochists! take er easy!

DIRTY BOOTS GERMANIUM OVERDRIVE

this little circuit is really what got me started in the whole DIY effects design process. i needed something that i could use to dirty up a loud, clean amp just enough to where it would have a touch of grit. it's a great little overdrive that can be used as a germanium booster as well as a fuzz if your pickups are hot enough.

it all started when i decided to breadboard the Trotsky Drive by Beavis Audio, which is basically a GE version of the Electra Distortion with a bias adjustment pot. using a russian GT313A transistor, i was fooling around with it, messing with values and such, when i remembered that the Bazz Fuss uses a diode in the C to B position instead of a resistor like the Trotsky/Electra. so i tried it out, and i got an excellently biased gain stage with just a bit of compression. then i realized that the circuit i was working on was PNP, where the BF is NPN. so the diode configuration is actually reversed. eventually i came to learn, with the help of many generous folks in the DIY community, that the GE diode that i was using was leaky, all of them are leaky, and it is this leakage that is actually acting as a large resistor and biasing the transistor. cool,huh? along with that, i'm sure that the diode is adding it's own little stamp on the situation with a bit of compression an break up.

after messing about with a ton of diodes this way and that, with filtering, in series, etc., i decided that i'm just not that big of a fan of diode clippers. i find them unnatural sounding, and their clipping just sound too "obvious" to me for some reason. so i ditched the clippers, added a small cap from C to B to roll off a bit of highs, and just put a whole nother stage in series with the first.

Lo! the Dirty Boots was born.

eventually i ended up trying a bias pot on the second stage and some different switching options for changing gain and tone, etc., but ended up with a normal emmitter controlled gain stage, a pregain control, and a volume pot. the latest mod was the series resistance between stages and ditching the cap from C to B on the second stage to open it up a bit.

it's really a great sounding little circuit using ge trannies which can be found on the bay for dirt cheap. the basic gain stage can be used for other things as well- it became the basis for The Toecutter.


give it a try sometime, or i'll send my band of mutated hobbit rat people to dig you out of your bomb shelter and eat you for second breakfast.

the thread at FSB about the Dirty Boots can be found HERE.

many thanks go out to Martin Chittum, Marcelo "Mac" Tripodi, and others that helped me understand along the way!



here is a layout using common sized parts. i have another for use with the extra mojo axial caps and such that i will post later.





daniel zink made this great version of the Dirty Boots in a Hammond 1590A box. a little killer!







here's another one from mr. zink- very stylish!