Saturday 22 January 2011

Krank Distortus Maximus


One for the metal heads or those looking for a bit more gain.  The offboard wiring will be a bit of a pain though!

72 comments:

  1. This is an effin awesome sounding effect. Pot wiring was a little bit of a P.I.T.A, but it's all worth it. I had to us a 100k for the gain whilst I'm waiting for my 50k's from Banzai (they take ages to despatch) and with the gain at zero, the effect is off, so the 50k is very much needed. I used shielded in/out cable. I also managed to jig it about so you can use a 25x9 stripboard. If anyone is interested, let me know and I shall elaborate on this. Good work again dude. Milkit

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  2. Update: It was a 25k pot I used for the gain & not a 100k as stated above however, the use of the proper 50k pot does nothing to stop the effect being off at zero. Not really a problem though, why would you build this effect to use as a light distortion? But I'm going to ask anyway, have I done something wrong, or is this normal operation? Thanks, Milkit.

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    1. Hi, sorry I missed your post, but belatedly, yes that's what you should expect. If you look at the schematic:

      http://i76.photobucket.com/albums/j6/IvIark_2006/Layouts/Schematics/KrankDistortusMaximusaccurateoriginal.gif

      The Gain pot in one position will take the second stage of the circuit to ground and so nothing could come out. So no it sounds like your pedal is behaving as expected to me.

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  3. I have this one in my sights but for the life of me I cannot find any 25k pots?? The only place I found was farnel but they have a £20 minimum trade order :( any ideas mate?

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    1. Scratch that, found a couple on Ebay... cost me all my fippin ice cream money mind!

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    2. Was just going to post this:

      http://www.ebay.co.uk/itm/120756600013

      Or I just did a simulation of the tone stack and it doesn't look too much different with a 20K so you could always try that.

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    3. Hmmm I'll keep that idea in mind,
      Cheers...

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  4. When you say 'tone stack', and the pic of the 25k pot you posted. I'm starting to worry that I've bought the wrong pot?! I brought this one

    http://www.ebay.co.uk/itm/Mini-alpha-25k-volume-Tone-control-pots-18mm-shaft-/130562014900?pt=UK_Guitar_Accessories&var=&hash=item641f98120e#ht_500wt_970

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    1. Well that auctions seems to be for either a linear OR log pot. You want 25K log (A25K) to be correct to the schematic (although both will work)

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    2. I got the log, I was just concerned as yours had two layers of lugs.

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    3. Ha ha, no that's just because I posted a link to the wrong type. DOH!

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  5. lol... phew! I thought 'What the ****!' ....All good then :) thanks..

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  6. My 'Distortus Maximus'

    http://s1170.photobucket.com/albums/r534/vince371/?action=view&current=1333220995282.jpg

    This pedal made realise I have testicles! Definitely recommend for the high gainers and head bangers alike :)

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  7. Hey Vince get one 50k pot and put a 56k resistor to 1 - 3 lugs
    in this way it becomes a 25k pot.... ;)

    Also Bass 1 lug goes to Mid 3 lug and Mid 1 goes to ground.

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    Replies
    1. Hi Satch, Thanks for the info regarding the pot. I managed to get a couple of 25k so it's ok now...

      regarding your grounding comment, I wired everything to the diagram and worked straight off the bat...

      The only thing was my Mid control worked in reverse, don't know if it was my error as I just corrected it and couldn't be bothered tracking all the wires, I just sealed the box and smiled :)

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    2. Thanks for the correction satch, I'll update the layout

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    3. I'm confused as to what correction it was? I wired everything the way your layout described and it works nicely?

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    4. It was just to swap the Mid 1 and Mid 3 wires

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  8. Oh right so that would explain my mid working in reverse...

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    1. Would a B1M be ok for the master as I only have one A1M left
      Thanks

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    2. I think you may have missed this ^^ ;o)

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    3. Sorry mate, I do miss them from time to time. :o)
      Yes just give it a go, it'll do the same job but with a different taper.

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    4. No worries mate...understandable ;o) I want to another but cram it in a MXR type box.

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  9. Is there a way to increase the gain (distortion) in this? I don't really want to change the IC as the tone is perfect.. just a little push in distortion would be good for squealing lead.

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    1. Also a possible bass increase?

      Cheers.

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    2. Did you use the 2N5088 transistor? If so try something higher gain like a 2N5089 or even a BC550C or MPSA18, and unless you have something to measure them, try a few to find the one with the highest gain.

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    3. Yes I used the 2N5088... So the tranny is the gain keeper? Right I'll try a few of them :)

      Any bass increase available?

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    4. There's the mod we discussed the other day with the Purple Plexi, but let me simulate the tone stack and see what we'd need to alter in there to get more bass.

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    5. This is the default tone stack values and showing with the High and Mid pots in the centre position, and the Low control dimed.

      http://i76.photobucket.com/albums/j6/IvIark_2006/DIY/krank_ts1.png

      If you swap the 22n connected to Bass 2 & 3 with a 100n, this is the difference:

      http://i76.photobucket.com/albums/j6/IvIark_2006/DIY/krank_ts2.png

      Not dramatic maybe, but the fact that you'll get a bass boost at the lowest frequencies may make a difference. Maybe socket that cap so you can do a few swaps to experiment.

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    6. Excellent. Much appreciated Mark!

      I'll get going with this when my switches arrive.

      I could even apply your switchable transistors switch to this..
      Rhythm and lead switch... What a beast It'll be! ;o)

      Cheers mate.

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    7. Another thing, what kind of tolerance is acceptable when dealing with pots? 25k logs are a pain to get hold of, not to mention pricey.

      20k logs are readily available, would that be ok?

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    8. It all depends on what it does to the tone stack, but I checked this one in the past and 20K and 25K both give a very similar response.

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  10. Made this up again with switchable transistors... I used the 2N5088 and a MPSA18... which gives me less gain? I tried a few different ones but same results.. It just sounds like 2N5088 with gain knob on half?

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    1. Well there's always the possibility that you've used a low gain MPSA18. The 2N5088 is listed on the datasheet as having gain between 300 and 900, and the MPSA18 is listed as 500 to 1500. So you could have a 900hfe 2N5088 and a 500hfe MPSA18. You'll be able to measure these when your multimeter arrives.

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    2. Yes, it's arrived but total crap lol.. You have to wiggle them about and I get sporadic readings. I'll see how it goes trying them all.

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    3. Ok.. finally managed to measure some, 2N5088 = 531 and the MPSA18 = 680... still a big drop in gain?

      The 2N5088 sounds like the first one I made, completely normal.. flick the switch to the MPSA18 and it drops? strange eh?

      Oh well I boxed it and it's done. No patience for farting about. I'll just use the 2N5088 as normal. :o)

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    4. I'd desolder the switch and put sockets there so you can experiment. Maybe try a darlington which will be much higher gain and see how it reacts, or maybe some other higher gain silicons like the BC550C, 2N5089 etc

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  11. I've socketed the switch and tried various others but they all seem to react the same.. either reduced gain or no sound... It's like there's something just refusing to let that much gain pass through?

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    1. Yes there will be a point of too much gain for the transistor to bias properly, that's why I was interested about the darlington and whether they had too much gain.

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    2. Oh well.. at least that avenue has been explored..

      This pedal also sounds extremely similar (or vice versa) to the Dimebag distortion but a hell of a lot better.. I thought the Dimebag was weak without a booster in front of it so this is a cracker for any Pantera fans out there.

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  12. Another for you; http://imageshack.us/f/855/dsc00136ua.jpg/

    Decided to rename it the 'Hellhound' with lighty up eyes too!

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    1. :o)... I fancy messing with this again, What would control the mids? the 22nf to the far right? If so, what reaction would I get for increasing/decreasing? cheers.

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    2. Excellent, cheers mate. I'll give that a try now ;o)

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    3. To get an accurate answer and to see what the values do just go here and download the Tone Stack Calculator:

      http://www.duncanamps.com/tsc/

      After you've installed it, on the left hand side go across the tone stack options until you come to the Marshall tone stack. To edit the values just double click on the one you want to change, then put in these values:

      C1 - 470p
      C2 - 22n
      C3 - 22n

      R1 - 33K
      R2 - 250K lin
      R3 - 1M log
      R4 - 25K lin
      R5 - 1M

      Then just mess around a bit with the values, and simulate the pot rotation using the sliders on the bottom left hand side.

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    4. Weird, my comment jumped up one lol...

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    5. I put the wrong value in for R1 so because I can't edit the posts I thought it was better to delete it and repost than correct myself in a later post just in case someone took those values as correct .

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    6. What a difference! I've made a mid switch of 22n/47n which makes a massive scoop!.. takes out the 'boxyness' of the pedal. And also a bass switch of 22n/100n which when the mid switch is scooped it has very noticeable bass increase. VERY heavy!.. Think BOSS MT-2 without the nasal nastiness. Very worthwhile mod/option.

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    7. just placed ANOTHER switch for the treble, 470/200pf... This thing is an effing beast now! the 200pf slightly scoops the upper mids making appear clearer and heavier. With all switches activated this is Cannibal Corpse galore!.. Jeez I haven't listen to them for donkeys.. must be getting old!

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    8. Very cool. When you've finished with your mods I'll do a Vince Mods layout alternative.

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    9. Cool, Well I've finished and decided to leave it.

      Bass = 22/100n switch
      mid = 22/47n switch
      Treble = 470/200p switch.

      I tried a 100p in the treble but it gave a big perceived volume drop.

      I've been playing with it for a while and I've noticed that all the switch positions can have an effect on each other depending on how the bass/mid/treb controls are set. So one switch may seem like it has little effect but once you adjust a pot you'll hear a change. Basically it's a tweakers dream.. chuffed with this.

      Cheers again mate ;o)

      C.S.I pedal lol
      http://img827.imageshack.us/img827/7905/dsc001521.jpg

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    10. Scrap the bass switch. It doesn't make a big enough difference to warrant it plus the mid and upper mid (treble) scoop give the feel of a bass increase.

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  13. Just finished this as my first pedal. I included Vince's mods and my friends wife did the paint job.

    Thanks a lot guys.

    http://imgur.com/a/kTWfs

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  14. Just finished the circuit and tried. No box, nor switch nor anything but circuit, pots and jacks still but the sound......

    BRUTAL!

    Thanks again Mark :)

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  15. Pedal finished, another one for your collection:

    http://guitarrasimportacion.foroactivo.com/t447-capinc-effects-7-hell-on-earth-krank-distortus-maximus-dedicado-a-alberto#6467

    Best regards!

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    1. Great looking build, thanks Javi! guitfan hates you though! :o)

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  16. i built one of these and slightly modded it for bass use. i tried six different 386's in it (LM386N-1, LM386N-2,LM386N-3,LM386N-4, a JRC386 and an NTE823. to me, the best one out of all of them is the LM386-4 since it has the best 'non-sputtery' note decay.

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  17. BTW, here's a pic of it:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/DistortusMaximus/DistMax-01.jpg

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  18. I built this today. Was very surprised by it's sound. It rocks severely, and i can easily dial in both warm, amp-like 90's tones aswell as mid-scooped modern deathmetal sound.

    This is my second build from your designs, and now i love your website twice as much :)

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  19. Just made this one yesterday and its sound so small and awful. Even with all the pots turned up, the sound barely came up. I swap 2n5088 with bc109 and the Mid pot with 50k. And all pots i used are linear bcause i cant find any Log.

    I know something wrong with my built, but i'm sure it's not the pot. Maybe the bc109 is the problem?

    Any help would be awesome! thx!!

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  20. Well, feel so fckin stupid right now. The bc109 isnt the problem. Hard to say, but, damn i forgot those links. After putting all the links together, it sounds amazing now.

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  21. I recently built this circuit and it does work and sound good until I turn the volume or gain up and then I get a really bad, uncontrollable hum. Anyone else experience this at any point of their build. Any idea where I might of goofed?

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  22. Hey there, i'm thinking about making a guitar amp, around 90W using a TDA7294, with a 2 preamp channels, one clean, using a tl072, and one distorted using the distortus maximus, and after them, another preamp, something simple. But... i need your help with the clean preamps.. you think you have any bit of time in helping me with this? Thanks alot.

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  23. For more gain you can change the emitter resistans from 390 to 100 ohm or even put the emitter to ground. You can remove the 56k resistans before the gain pot. But when you increase the gain, the signal will be difficult to controle. I put a res from the gain pot to earth and now I can get a clean sound with the gain on minimum. I made a standard Fender tonestack and Wham!!! Big, very Big ballsy SRV sound!!

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  24. HI Mark,

    Is their any chance you could add Vince's switch Mods to the layout. I don't quite understand were he has put them.
    Thanks in advance.

    Gav

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  25. Replies
    1. if you're referring to the on/off stomp switch they're not included in any layout as it's the same for every build, with the exception of buffered effects. you will find how to do it here:

      http://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html

      i would suggest that you read the build guide first before building anything else:

      http://tagboardeffects.blogspot.com/2012/04/vero-build-guide.html

      this will explain how to build an effect from start to finish.

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  26. ivark why in the tone stack calculator are we putting lin for some of the pots when the layout says there all log, wont that make a difference. im a newbie sorry if its a stupid question lol

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