Friday, 3 February 2012

ZVex Mastotron

A few people have requested a vero of the Mastotron, so here it is.  If you want to make it verbatim then you would put a 100 ohm resistor in series with the input wire before the pot, and a 100 ohm resistor in series with the 9V supply wire, but I personally wouldn't bother with either.  So enjoy your Woolly Mastotron!


Posted by at 00:14
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79 comments:

  1. Anonymous4 May 2012 at 19:12

    Well I did sit down to finally do the Orange squeezer then realized I forgot to order more 1N34A's!...So you can verify this instead :o)

    Just one thing though, the 'PW' wiring needs flipping as it worked backwards.. This is really nice, Especially for people who don't like the noises of the Fuzz Factory..

    ReplyDelete
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    1. Anonymous4 May 2012 at 19:27

      This comment has been removed by the author.

      Delete
    2. Anonymous4 May 2012 at 19:30

      Imageshack removing my pic!!

      http://imageshack.us/f/137/dsc00136yk.jpg/

      I used the case from my 'King Of The Britain's' failure....

      Delete
    3. IvIark4 May 2012 at 19:38

      Ha ha, excellent, waste not want not!

      Delete
    4. Anonymous5 May 2012 at 10:54

      This is also verified by the way :o)

      Delete
    5. IvIark5 May 2012 at 11:21

      Forgot to change the tag, cheers mate

      Delete
    6. mirosol19 September 2012 at 19:20

      Vince! Your photos are gone again.. :(
      +m

      Delete
  2. Dragon Ninja19 September 2012 at 18:42

    I have 0 pedal building/soldering or circuit board printing experience.
    How would I get the circuit board that I would need to try and build this or any pedal?

    Thanks

    ReplyDelete
    Replies
    1. mirosol19 September 2012 at 19:18

      Check out this guide:
      http://tagboardeffects.blogspot.fi/2012/04/vero-build-guide.html

      Stripboard is sold at almost every electronics component store. Taydaelectronics is pretty good shop, as you can get almost everything you need from there.

      So.. The stripboard doesn't need any printing, but just trace cuts - and those can be done with a knife, drill bit or what have you. There is a tool for that too: http://www.ebay.com/itm/220509678716

      For starting out, i would however suggest something a bit simpler, like ROG Buzz Box:
      http://tagboardeffects.blogspot.fi/2012/09/runoffgroove-buzz-box.html
      or some simple booster, like Catalinbread Naga Viper or EHX Hog's foot:
      http://tagboardeffects.blogspot.fi/2012/08/catalinbread-naga-viper.html
      http://tagboardeffects.blogspot.fi/2012/05/ehx-hogs-foot.html

      I personally started with kits from General Guitar Gadgets and Musikding. Those are good, because you don't have to know all the components when shopping..

      Anyway. Welcome :)
      +m

      Delete
  3. Strange Amps27 September 2012 at 08:54

    There's a photo of Mastotron guts on the web somewhere, and to me it looks like the Pulse Width pot say 500R and not 500K. Anyone else notice this or look into it?

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    1. IvIark27 September 2012 at 09:06

      A 500R wouldn't make much sense in the position it is in so I would doubt it. The PW pot is a modification to the 100K feedback resistor found in the Fuzz Face. In the Mastatron it has a 100K in series with it and so it means the feedback resistor is variable from 100K to 600K. If it was a 500R it would be variable from 100K to 100.5K and I doubt anyone would notice any difference.

      I'd probably experiment with the 100K series resistor and use something lower so you can make the value smaller than the 100K found in the Fuzz Face depending on the PW pot setting. Just so that you can vary it up or down.

      Delete
    2. stOOn19 October 2017 at 08:42

      That sounds true. The pot PW visible in this picture seems to be a 500R.
      https://images.talkbass.com/attachments/img_1191-jpg.1714122/

      Delete
  4. Strange Amps27 September 2012 at 09:23

    I assumed as much since the math doesn't add up, must be a bad print on the pot in the photo. Thanks for confirming.

    ReplyDelete
  5. Pedro Cardoso17 November 2012 at 18:53

    I built one pedal with this layout, and i'm having some troubles in making it work.
    I'm a bit of a newbie, as this is my third project. The other two pedals that i've built are working great, this one is completely dead when i turn it on.

    I've assembled an audio probe to help me debug the circuit (using a Wima 100nf, and a clamp for the ground), and the sound in the audio path is stopping at the first transistor. After that no sound at all. What could it be?

    It's worth noticing that i'm not using this layout literally, one of the caps that i had available for this project was a bit bigger that the space that i had for it, so i used a mini vero board to hold that capacitor in other place. I'm pretty confident that I done that modification correctly, but being a newbie that I am, I'm starting to doubt everything.

    Any hints on how to solve this would be great.
    Thanks in advance.

    ReplyDelete
  6. Pedro Cardoso18 November 2012 at 14:41

    I'm starting to think that i connected the power plug with the wrong polarity. If this assumption is correct then i might have fried the transistors right? The electrolytic caps visually seem ok (no dilation etc). And considering that the sound stops at the first transistor it might be that one that fried blocking the signal for the rest of the circuit.

    What do you think?
    And how should i connect the power socket? Negative to ground, and positive to feed the circuit?

    ReplyDelete
    Replies
    1. IvIark18 November 2012 at 17:11

      Very possibly, that's why I always socket transistors so it's a quick and easy fix if anything happens. For the supply negative goes to ground along with all other points of ground, i.e board ground, socket sleeves, stomp switch for LED circuit, pots etc.

      Delete
    2. Pedro Cardoso19 November 2012 at 15:52


      Well... it wasn't that, and it was such a simple error that i'm a bit embarrassed for not realizing it before. I had one of the pots cables misplaced on the board, creating a path that isn't supposed to happen, and was obsessed that the error was in the power supply part of the circuit.
      Once i realized what was wrong it was a quick fix.

      Well thanks anyway for the quick answer.
      The pedal is working fine and today I will try to rock it a little bit.

      Continuation of the good work on this site, I stop by every day to see the new stuff.

      Delete
    3. IvIark19 November 2012 at 16:49

      Glad you got it going Pedro. Everyone makes these errors from time to time. I spent hours fault finding a TS type pedal once before realising that I hadn't put the IC in the socket yet.

      Delete
    4. dexxyy19 November 2012 at 18:03

      Yep, done that, also spent hours debugging a build only to find I hadn`t turned my power supply on. I have numerous nominations for idiot of the year, fortunately there`s always a politician can trump me. :-)

      Delete
  7. Unknown2 December 2012 at 00:33

    Hi, what types off caps are used for the 220n, 33n, & 10n. Also are the transistors npn? Should the caps at least be 16v?

    ReplyDelete
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    1. IvIark2 December 2012 at 02:58

      Use whatever caps you have that are suitable for the 2 or 3 row spans required. I used all polyester caps when I built this, but I wouldn't worry too much about type. Some people swear by polyester, some will only use ceramic caps in fuzz pedals but the effect is so extreme in this case that any differences are subtle at best and not worth worrying about. Yes the transistors are 2N2222A which are NPN.

      Delete
  8. Unknown3 March 2013 at 17:10

    Would someone help me out by writing up a quick list of all the components used for this build? 1:1 as possible. This would be my first major build and want to double check I'm reading the schematic correctly.

    ReplyDelete
  9. Unknown7 March 2013 at 03:01

    I would also like some help putting together a parts list. I was wondering if the 220n capacitor and similar looking ones are mylar or some other type?

    ReplyDelete
  10. Unknown7 March 2013 at 04:43

    is this a correct list?

    1/4 jack (2)
    9v jack (1)
    3 pos DPDT switch (on-off-on)

    100k Lin Pot
    5k Rev Log Pot
    500k Lin Pot
    10k Lin Pot (2)

    Transistors NPN 2N2222A (2)

    -Cap-
    100u (4)
    220n (2)
    33n (1)
    10n (3 span) (1)
    10n (2 span) (1)
    68n (1)

    -Res-
    56k
    22k
    100k
    2k2
    5k1
    10k

    ReplyDelete
    Replies
    1. Unknown7 March 2013 at 04:44

      does it really matter what types of Caps i use for a one off build? (like mylar, etc..)

      Delete
  11. Unknown7 March 2013 at 21:07

    Hey Guys

    I Just got the inventobox module by Zvex and am very much looking forward to building the mastotron effect. however like Dragon Ninja, I have no experience with building a pedal effect or any experience with circuit building. I check out the tutorial given to Dragon Ninja, but it seems they are building it without a breadboard.

    The inventobox comes with a breadboard built in already and I am not sure but I think im looking for the mastotron module or at least a breadboard friendly schematic for this module. Can anyone give me some advice?

    ReplyDelete
  12. Unknown6 April 2013 at 02:09

    so i accidently ordered a 500k revese log pot for the fuzz instead of the 5k. will this make an extreme difference? can i get away with using the 500k or should i order the 5k?

    ReplyDelete
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    1. IvIark6 April 2013 at 03:05

      The 500K will be useless for this, you really need the 5K. Don't worry though, there are plenty of other things you could use the 500K for so it won't go to waste.

      Delete
  13. Unknown8 April 2013 at 01:40

    i built this and when i press the switch i dont get anything. i get the bypass signal when its off. i used a 5k linear pot for the fuzz and used the offboard wiring from this site. any ideas on what went wrong? is it a problem with my switch wiring?

    ReplyDelete
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    1. Unknown8 April 2013 at 01:42

      or maybe a jump on the veroboard that shouldnt be there?

      Delete
  14. Unknown9 April 2013 at 00:00

    now i have a very low signal. i can very faintly hear it when i crank my amp and slap the pickups but i am getting some sound now. any ideas?

    ReplyDelete
    Replies
    1. Anonymous29 October 2013 at 22:03

      i am having the same problem as Ben....did you figure it out?

      Delete
    2. Dave30 October 2013 at 10:02

      This is usually caused by either incorrect component placement, incorrect component values or solder bridges, I'd double and triple check these things before asking for more help.
      Cheers
      Dave

      Delete
    3. Anonymous3 November 2013 at 03:07

      so so i had the transistors backwards...would that damage them? after turning the around i got audio and all the knobs worked but it didn't sound as tight and huge as the stock mastotron i had with me. is that just this build (the way it sounds) or did i damage something.

      to clarify it sounds like a fuzz just not as unique as the mastotron sounds...

      Delete
    4. Dave3 November 2013 at 12:14

      Potentially, you might want to try swapping out the transistors? Did you socket th transistors?

      Delete
    5. Anonymous3 November 2013 at 17:36

      i will see if my local radio shack has some so i don't have to wait for them to ship from Thailand ;)

      no i didn't socket them...i will try that too. I'm pretty handy with a solder iron (i work for a live audio company) but I'm guessing these things are pretty fragile.

      also would the use of Film box Caps over Mylar greenies make a huge difference?

      thanks for responding so quickly!

      Delete
    6. Anonymous3 November 2013 at 17:44

      ALSO how much would this affect the sound of the build?

      "If you want to make it verbatim then you would put a 100 ohm resistor in series with the input wire before the pot, and a 100 ohm resistor in series with the 9V supply wire, but I personally wouldn't bother with either. "

      this was in the opening description....

      Delete
    7. Dave3 November 2013 at 18:06

      Yes, it's always a good idea to socket transistors as they are easily damaged by heat, and it's easier to correct orientations.
      Using film boxes will be fine and make very little difference. The 100ohm resistor just brings down the input gain slightly, but it is such a small amount that it makes hardly any difference. I built mine without it and it sounds exactly how it should.
      Cheers
      Dave

      Delete
  15. Doron Barness11 April 2013 at 22:41

    Here's my build of the Mastotron with some audio clips of guitar and bass. Doom metal and stoner rock is written all over this one.

    http://fuzzquest.blogspot.com/2013/04/fuzz-testosteron.html

    ReplyDelete
  16. Thom__stone27 April 2013 at 16:05

    right every time I build this circuit it turns out all splatty and biasy and kinda crappy. first time i have tried this layout over the other with different trans. still won't work.... wtf am i doing wrong.

    http://www.youtube.com/watch?v=SFiGVtqlnGE

    ReplyDelete
    Replies
    1. IvIark27 April 2013 at 18:31

      What voltages are you getting at the transistor pins?

      Delete
  17. Thom__stone28 April 2013 at 11:07

    how would I test this? just attach negative from my multi meter to ground and then probe the pins with positive and take a reading?

    if so

    C1 1.23v
    B1 .57v
    E1 (not sure how to measure this as its at ground... so....0?)

    c2 2.77v
    b2 1.23v
    e2 0.63v

    sorry if im totally barking up the wrong tree here. I'm pretty handy at the old soldering and boxing up of these band boys... but ask me to diagnose a circuit issue then Im stumped.

    ReplyDelete
  18. IvIark28 January 2014 at 01:38

    Well if you heard a pop on the fuzz knob it points quite strongly towards that right hand 100u cap. I'd try swapping that and see if it was the culprit. Apart from that a pop could be caused by an poor connection somewhere or maybe an intermittent unwanted bridge that is barely touching. So first port of call would be to knife the gaps, and redo all the cuts to make sure there are no unwanted burrs in any of the holes.

    ReplyDelete
  19. Unknown3 April 2014 at 19:06

    Does anyone know if it makes a difference using a 2N3904 instead of the 2N2222 for the transistor? the place I normally order from does not have the 2N2222

    ReplyDelete
    Replies
    1. IvIark3 April 2014 at 19:17

      Should be fine, they're both low to medium gain NPN silicon

      Delete
    2. Unknown3 April 2014 at 19:44

      also do you have to measure the hfe of the transistor on this one as some mentioned in the mammoth build?

      Delete
  20. atha bayu15 April 2014 at 02:00

    hey, i own a wholly mammoth with pcb clone :) and i play an active bass. so, i need a push and relax scematic, and how to solder it, can you give me dat schematic? just send to atha.bayu@gmail.com

    thanks :)

    ReplyDelete
  21. hobbiesaremyhobby23 November 2014 at 19:16

    Quick question...
    ...With the tone witch in the center position, I have no output. Any suggestions on what to look for? It is an on/off/on dpdt switch correct?

    ReplyDelete
  22. Travis23 November 2014 at 21:01

    I'd look first at that 33n in the bottom right corner. Make sure it's soldered in correctly and not defective

    ReplyDelete
    Replies
    1. hobbiesaremyhobby24 November 2014 at 01:00

      Many thanks!! I got it. I have a Woolly Mammoth too, but wanted to try this. I will A/B them soon.

      Delete
    2. Francesco2 January 2016 at 02:25

      This comment has been removed by the author.

      Delete
  23. Unknown21 December 2014 at 08:07

    This was my first build and It worked! It is a christmas present for my girlfriend, but Im ready to build mine.
    Im thinking on getting a little bit crazy and try something like the "magnavibe" circuit to add depht/rate control to modulate the pulse width in order to get modulated synthy sounds.
    http://tagboardeffects.blogspot.com.es/2012/01/bigfoot-fx-magnavibe.html
    I could wire the circuit needed , (resistors, caps, led and lcr), on a different vero, wired to the 2 extra pots, (depht/rate), and then to the PW knob.
    What do you think¿
    Best regards.

    ReplyDelete
  24. Unknown22 December 2014 at 00:43

    I forgot to say that I am just getting some gain from the fuzz pot from about 80 percent of the running in advance. Below that, nothing but nothing. I purchased a standard 5k log pot for that: May be a lower value¿
    Best regards.

    ReplyDelete
  25. The Hudsons5 February 2015 at 22:35

    This is probably really obvious but, how do I add a bypass stomp switch to this? I am guessing that it is just not shown because it is so obvious. Thanks

    ReplyDelete
  26. Ciaran Haslett5 February 2015 at 22:39

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

    ReplyDelete
  27. Unknown7 February 2015 at 15:10

    Hi there, this is my first build, I used the layout above and the off board wiring diagram from this site. I put it all together, plugged in the power supply, pressed the footswitch and I got a quick flash of the LED and then nothing at all. When I tried to switch it on again I get absolutely nothing. When I switch it off I get the dry guitar signal. Does anyone know what might have caused this? Thanks.

    ReplyDelete
    Replies
    1. Unknown7 February 2015 at 15:56

      I just used the Beavis Audio off board wiring, the LED still doesn't come on, but I'm getting some really high pitched squealing / oscillating noises that seem to change when I mess with the PW knob. There is also a loud pop between positions 1 & 2 on the toggle switch, 3 seems to be fine. Any ideas?

      Delete
    2. mirosol7 February 2015 at 16:52

      I'd bet you have a short in there somewhere that's causing a feedback loop. Possibly in the switching. This could also explain the toggle behaviour.
      +m

      Delete
    3. Unknown8 February 2015 at 12:17

      Thanks man, I checked all my wiring and I can't find any touching. Could this be caused by solder bridges / cuts not properly done?

      Delete
  28. CheapChip8 July 2015 at 09:13

    Hi,
    I have the same problem as above, but it is a loud percussion-like oscillation that varies turning pw clockwise. And frequency is doubled with 3rd position of the switch...
    Last but not least: sustain is quite short, with high notes particularly.

    ReplyDelete
  29. CheapChip8 July 2015 at 09:27

    I forgot to say that at turning the effect on , it can be quiet. But cycling pops begin after playing a note or a chord.
    Sometimes, sustain ends in a sort of tremolo way. :-S

    ReplyDelete
    Replies
    1. CheapChip16 July 2015 at 08:50

      Hi ,
      Found what was wrong with my build !
      I compared my voltages with those posted by Mark for the Wooly Mammoth build. Q1 was OK but Q2 collector was starved to 0.9v...
      Swapped 22k resistor with a trimpot and tuned it for a decent voltage.
      That could be a mod idea: replacing 22k with a external pot could be a sort of gate/glitch control.

      Delete
    2. CheapChip16 July 2015 at 08:50

      This comment has been removed by the author.

      Delete
  30. Anonymous5 August 2016 at 23:02

    Old layout i know, but i cannot get it to work.
    How would you test this before boxing it up? with all the pots etc.. i am used to all the connections are on the board but here it just goes from the input at the pot right? so that the board input is the input wire at the first pot? i tried boxing it up, but i dont even get bypass, so something it definately off.
    greetings from Denmark.

    ReplyDelete
  31. Unknown20 August 2016 at 01:20

    So I build this originally a couple months ago, and when I did, I didn't have any 2n2222a's on hand, but in the comments I saw someone asking about 2n3904's, and I did have some of those, so I built it with them and I loved the way it sounded! Super thick and farty (playing bass through it.
    Now, I just recieved some 2n2222a's and swapped them into it and tested it out, and I gotta say,I don't like the sound at all! I have to turn the fuzz all the way up to get that thick farty sound, but then it gets all choppy and cuts in and out. I swapped the 2n3904's back in and it sounds awesome again!
    I know they're not to spec with the original, but give them a try if you have some laying around! You won't be disappointed!

    ReplyDelete
    Replies
    1. Unknown6 October 2016 at 00:27

      Did you check the pinout? I also tried 2n2222a's and had the same problem. Then I realised the pinout was different and I had to flip them around :)

      Delete
    2. Unknown6 October 2016 at 00:28

      http://electro-music.com/forum/phpbb-files/figure8_1_165.gif

      Delete
    3. AlexS15 January 2017 at 05:41

      I also prefer it with 2n3904 over the pn2222a and 2n2222a's I tried.

      The 2n3904 is used in the 2 other related fuzzes, the Mammoth and Fuzzolo.

      Delete
  32. mondel plasmid23 October 2016 at 16:42

    Hi, this is my first build from this site and I've bought tantalum 220nF capacitors. I have no idea which way round to put them! Can someone advise? Thank you.

    ReplyDelete
  33. Travis23 October 2016 at 18:07

    You should use film caps instead

    The 220nf on the left will have the + side facing down, the one on the right will have the + side facing up

    ReplyDelete
  34. iiimonfire25 January 2018 at 16:22

    I don't happen to have an ON/OFF/ON switch on hand. Technically, couldn't I use the same wiring for an ON/ON/ON switch and get the same results?

    ReplyDelete
  35. befey17 May 2019 at 14:26

    Did the PW wiring get fixed in this layout, or does it still need to be reversed? Comparing to a schematic online, it looks like it still needs to be reversed.

    ReplyDelete
  36. francois Junquas12 July 2019 at 16:25

    Hi,
    i build this one and work just fine except for the tone pot.
    Not effect at all on the sound... I check and recheck and rerecheck everything and all seem to be just correct with the shematic. All conponents are check and are at the right value.I made many build with success but on this one i just cant figure whats wrong. Anyone else have this problem?

    ReplyDelete
  37. Cherepaha16 April 2020 at 10:02

    Hello!
    I build this project, but i have a problem: i have volume drop when i swithing on the pedal. All knobs are work, i have fuzzy sound, but it less loud compared clean sound. what should i check?

    ReplyDelete
  38. Paul15 February 2021 at 22:48

    Built this today for fun. Sounds great!

    I tried 2n3904s, but liked the 2n2222s better. I also tried 2n5088s, which were interesting, but the higher gain changes the character considerably.

    I don't currently have a reverse log 5k, so I went with a linear 2k pot (similar to the Woolly Mammoth) and it does the job well (most of the action seems to be between 0-2K of resistance anyway).

    ReplyDelete
  39. Chris11 August 2021 at 21:42

    Hi all,

    I'm interested in the build for the push/relaxed but already have a woolly mammoth. Would adding a 100k lin to mt input serve the same purpose on that pedals save just building a new one for it?

    ReplyDelete
  40. Le Comte de Fourques3 June 2022 at 11:57

    BC 108C are nasty in this circuit , the transistor's pinout is opposit.

    ReplyDelete

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