Sunday 21 April 2013

Mojo Hand Iron Bell Fuzz

Info about the original:

David Gilmour’s lead guitar tone throughout the years has consistently been as varied as it is sought after. Numerous different fuzzes, overdrives, and boosters coupled with various amps and guitars have created some of the most gloriously rich and vibrant tones in the history of rock. While it’s clear that no sole effect can alone duplicate the “Gilmour Sound”, when it comes to fuzz…his go to unit for the majority of his career has been the legendary Big Muff, and with so many different incarnations and variants being employed at different time periods, his tone has remained extremely difficult and elusive to pin down.
The Iron Bell isn’t based on any particular Muff circuit. Instead, we’ve tweaked it to be a platform that is wide, yet focused.  Unlike the Colossus Fuzz which is based on the Sovtek/Civil War era Muff, the Iron Bell is voiced to be very open and rich, with an almost 3D like harmonic quality. Alongside the standard Gain and Volume controls, the Tone and Colour knobs allow you to sculpt the overall spectrum of the EQ. That Iron Bell is tweakable enough that combining it with various set ups and effect combinations will allow an ample array of colors and shades.
The Iron Bell’s main focus isn’t meant to be “David Gilmour in a box”, it’s more a tonal tool that can be used in countless ways to get the type of epically soaring, yet manageable quality of sound that has become the signature calling card of one of music’s most legendary players.  The Iron Bell can be much more, and can serve as a tool to take your tone as far as your imagination will allow.






61 comments:

  1. Can you confirm if there is really 17 cuts, I can only see 16 :-)

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    1. lol, I just didn't want to go mad searching for another cut, if it wasn't there.

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  2. Mm, I definitely gonna build this one !

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  3. A Muff with a contour pot. It sounds like every other muff.

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  4. Basically...it's a muff....probably a good one, too. Gilmour started using muffs around 1975. If you are more into older sounds, go to the fuzz faces. His main amp was a Hi-Watt.

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  5. That video makes me want to build this right now. Sounds fantastic, especially on the bass. :)

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  6. waiting on a few parts.. I will compare to my Iron Bell...ended up getting one for Christmas from my fiancé. I will admit it is my favorite pedal I own. Tons of usable tones and sustain is amazing!

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  7. What does the contour knob do?

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    1. It works hand in hand with the tone control and will be fairly flat counter clockwise with quite a large mid boost clockwise. Then the tone control will affect the overall bass/treble content as per usual with the muff tone control.

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  8. General,comment . When using fuzz circuits built here and commercial,ones , I get a lot of noise when powered by my soundlab 450 pedal psu . No problems with battery's. Weirdly some pedals including my joyo ultimate distortion hum uncomtrolably when the guitar volume is down to zero . It must be the psu right ? . It has been reported as a noisy psu on other sites mind . Any idea of adding some power filtering to some of the fuzz circuits like this one and others posted here ?

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    1. The power supply may not be noisy for other people, because they don't have your main supply. If they're quiet with battery but noisy with this PSU then it gives a clear indication of what is to blame. DO you have a mate with another type of power supply that you can test it with? If you have a noisy mains supply then others types may be noisy for you too in which case you may require some sort of power conditioner to keep things quiet.

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    2. Thanks mate . I agree , I think I'll have to do some experimenting . Strange effect though when turning guitar volume to zero gives a loud in controllable hum , I imagine it's something to do with the grounding and power issues . Could I use a capacitor across the supply to the pedals to filter out some noise ? I think however I'll try another psu . Many recommend a 1 spot

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  9. THE BELL TOLLS!! If not already you can 100% verify this one. It bloody outstanding. Very easy to dial in some sweet tones. I ended up using mpsa18 trannies at around 630 hfe because I'm really struggling to get any more than mid to high 500 hfe from my batch of 2n5089, bc550c etc.
    The pF caps are working well with no fizz at all.
    Thanks guys, this has made my day, cheers!

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  10. No worries mate, it's a pleasure. Rock on maties!

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  11. Finished one.
    But the volume is way to high compare to the bypass volume.
    Any ideas?

    Thanks

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    Replies
    1. The volume pot attenuates the signal and will take it down to nothing. If it isn't doing that then you either have a faulty pot, or maybe forget to make the Volume 1 connection?

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  12. Hi folks. Long time creeper, first time poster. I've been successful first time every build (6) and must have gotten cocky cos for the life of me i cant figure this one out! Board built and jacks wired up (not in box yet so no switch).

    Volume works, tone works and contour works (i think) Sustain/gain seems to work too but greatly shows up my problem...and that is...

    Its very gated sounding (fuzz factory gated!). With sustain full up it sounds nice and fuzzy but theres this weird envelope that ramps up about 1 second after i play a note then falls down again. It also sounds stuttery for the first second before smoothing out but by that stage the gating effect kicks in. Rolling the sustain back does reduce gain a bit but the gating effect becomes worse. Rolling back guitar volume is just as bad.

    Substitutions ... 30k at input swapped for 33k and 56n at Q1 swapped for 47n

    Cheers for any suggestions and apologies for the novel.

    Keep up the great work!

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    1. sounds nice and fuzzy + weird envelope + stuttery = I want that pedal :)

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    2. Haha...if I can't get it sorted you're welcome to it!

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  13. Just built this one, sounds great!

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  14. I'm building this pedal as a gift for my girlfriend's birthday. When the pedal is bypassed, the signal passes through. When the 3PDT switch is clicked, the LED turns on, but no signal passes through. Can anyone help me debug a defective build? I don't know too much about soldering, but my joints don't look like what I think a cold solder joint looks like. I double checked the transistor pinouts, diode direction, and the electrolytic capacitor. They seem to be oriented in the right direction. Do these photos shed any light on the situation? Is there more information I should provide?

    http://i1277.photobucket.com/albums/y495/tominjapanman/topview_zpsbf2dd463.jpg
    http://i1277.photobucket.com/albums/y495/tominjapanman/circuit_zps00a668d4.jpg
    http://i1277.photobucket.com/albums/y495/tominjapanman/topview1_zpsed6cbc90.jpg
    http://i1277.photobucket.com/albums/y495/tominjapanman/withpedal_zpsdbe05398.jpg

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  15. I'm still trying to figure out where the signal is getting lost in the circuit. Can anyone provide me with a schematic? I'm rather new to this sort of thing, and it's easy for me to lose where the circuit goes on the stripboard. If I had a schematic I might be more clearly able to follow the circuit from start to finish.

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  16. I'm still trying to figure out where I went wrong. Since I don't know too much about using a multimeter to see where the signal is lost, I did a second build with extra parts I had. I was extra careful to make sure the diodes, electrolytic capacitors, and transistor pinouts were correct. However, on my second build, the same problem happens: Signal travels through on bypass, no signal when effect is engaged. Can anyone take a look at the pictures I posted above? Are there any really obvious mistakes I've made?

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    1. Are those meant to be cuts? you may of missed?

      http://i1086.photobucket.com/albums/j441/music_vinny/cuts/Cuts.jpg

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    2. They aren't meant to be cuts. I marked about four holes on the copper side before realizing the vero layout supplied was oriented to be marked on the other side.

      I actually gave up on this circuit and just built a Fuzz Face. Maybe this had been a little ambitious for my first build, but it sounded so cool!

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  17. Anyone got transistor voltages? Pretty sure mine are wrong. Probing seems sputtery at Q1
    Q1 Q2 Q3 Q4

    C - 4.3V 6.25V 3.9V 1.5V
    B - 0.66V 0.63V 0.64V 2V
    E - 58mV 54mV 68mV 1.47V

    Cheers

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  18. I just built this one today and it sounds great!

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  19. Done!

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/IronBell/Ironbell-01.jpg

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/IronBell/Ironbell-02.jpg

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  20. Just finished this one Last night.
    Sounds great and it has lot's of variety but I was wondering if there's a way I can add more "Fuzz".

    http://i.imgur.com/JWtBEhp.jpg

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    1. I must have done something wrong, it sounds more like an overdrive than the Video and other reviews I watched.

      http://i.imgur.com/HzQJOjS.jpg

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  21. Hey all, got a weird problem with this build and was hoping someone could help me out. Everything works, apart from the volume control, i hear only a vary slight difference in the volume. So i replaced the pot, same thing. I checked the wiring to the pot and re-soldered same thing. Then i changed the 330uf cap near the volume control pot, no joy. What else do i need to be looking at that might cause this? Thanks!

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  22. The demo sounds amazing, gonna try this one out.

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  23. What a nice pedal. A LOT clearer and articulate when compared to a muff.

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  24. Remade this one over the weekend.
    I got fristrated while making the first one and y looking at my prevouse post it's no wonder why it didnt work. SO MESSY.

    I really like this pedal and it fired up on the first shot.

    http://i.imgur.com/EM0ezB4.jpg

    http://youtu.be/9P2ycsqEERY

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  25. This comment has been removed by the author.

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    1. NO. it should have a lot of effect. you have an error in your build somewhere.

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  27. I read through the comments and I wonder how weird this circuit is. many people had strange problems. in my build the tone knob acts like a gain in reversed. fully clockwise there is no sound. I must have an error in my build.

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    1. hey man. there's definitely a build error causing your problem. besides building this myself and it working first go, all this circuit is, is a big muff with a mids control. if you can't figure out what's going on in your build, post up the problem and some pics of your build in the debugging section of the forum and i'm sure a few people can help take a look and figure out the problem. i know i'll be happy to look.

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    2. there was a short. it's behaving a lot better now.but to have the unity gain I must keep the volume almost at zero point. Is it normal for any pedal? if not I will post up the problem in debugging section as you said. thanks

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    3. hey Zach . I read trough the comments in green russian big muff. and learned that your muff unity gain is at 9 o' clock. but when I say almost zero I mean it. anyway it's probably normal. but is the sustain a kind of gain control ? I mean is it normal for it to affect the volume?

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    4. well,That is normal too. I should have read more carefully .IvIark had answered this question too. Ok , so another one ,I hope I won't find the answer by myself :). as another one mentioned in this tread, when I hold the note for too long the sound breaks at the end. Is it normal too? And I found that when I touch the ground rail (right side of the 100u cap) and above row (Which has the diodes on it) at the same time, the effect becomes dead silent noise wise . the sustain and tone is slightly affected though. of course I could not play at the same time.to examine the side effects .What is it? can you explain it to me?

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    5. every muff is a little different. my iron bell is very very very loud as well, i'll have to check to see where unity is. my russian green muff really has unity lower then 9 o'clock, probably more like between 7 & 8 o'clock, i just drive my amp a little with the muff.

      if i understand what you're saying about touching the two rails you're grounding the effect and you won't get any sound out of it.

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    6. no there is sound. but the noise is all gone. what about the breaking down of the hold notes is it normal. thanks

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  28. Hey.
    I built this schem and when engaged, my sound is 100% clean. Tone knob seems to do nothing, volume is active and sustain is at least partially active but doesn't do much.

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    1. Hi,

      You've made a mistake somewhere. I've built 3 pcs and they all sound great and are fully operational, except the contour knob, which is still kind of mystery for me.

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  29. Hi, works great but volume pot is way to high. Impossible de clockwise it more than 12h00 without I lose my ears.... is it normal ?
    Thank you

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  30. Sucess build, such a nice sound fuzz..
    great thanks for the layout again,
    sharing some shots here: https://goo.gl/photos/W5q8UC1bticxdTjZA

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  31. this was my 5th pedal build,all worked good but this one. no sound at all, reflowed all joints and cleaned between strips, could someone give me a starting point or some voltages to test it with, never had to do this, I built an audio probe but not sure where to start with it as I dont have a schematic.

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    1. Can you provide some voltages? Post them and some hi res pics to the forum Debugging section and we'll have a look.

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  32. ok q1-c.72,b.72,e.10 q2 c.80, b.79, e.18 q3 c.74, b.73, e.14 q4 c6.88, b7.62, e6.87 will try to get pictures my phone is not very clear

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    1. thanks to the guys on the forum the iron bell is now tolling!!! I had 470r's in place of 470k's and had the input in the wrong strip! Oh well no more late night building and beer!!!! Thanks to all helpers!!!!!

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  33. for anyone who want more gain, easy to down the Q2 & Q3 emitter resistor 'Q2=270r Q3=390r' to 120r or your taste.. enjoy!

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  36. Very nice and versatile take on the big muff.
    Powered up right away and I think even my neighbours like it.

    I think there's nothing I'd like to change except a log pot for volume but that's just my preference.

    Thanks for the layout!

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