Tuesday, 20 March 2012

Mad Professor Stone Grey Distortion

Info about the original:

BJF design distortion pedal for guitar

The new Mad Professor - Stone Grey Distortion (SGD) is a modern high-gain distortion pedal with unparallelled clarity and definition.

This pedal was developed for high gain applications and specifically for clarity at heavy distortion levels.

The Stone Grey Distortion is unique in that it has razor sharp dynamics and high gain intensity. It's ready for drop tuning, 7 string, and modern rock players who are seeking extreme gain with intense "string to string definition".

Play a chord and hear each note distinctly, instead of it turning to "mush" like many other high gain pedals.

With the gain turned down, the Stone Grey Distortion approaches overdrive-like textures and responds to the player's touch and dynamics like our other Mad Professor pedals do.

Build the Mad Professor way: small footprint and big tone.

Controls

VOLUME: sets the output level of the distorted signal

DISTORTION: sets the level of distortion - lower levels more overdrive-like textures - higher with heavier distortion.

TONE: sets the critical treble response for use with various amplifiers.





Here's an alternative layout for those who want to use mosfets instead of JFETs:




Now verified and here's Milkit's pics showing the double links, just as an added visual guide:




and Geiri's demo of his build:



119 comments:

  1. Aces, get some new IC's & 'll build this mofo. Anyone that uses Mastodon riffs to demo a pedal has me hook, line & sinker! ;0)

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    1. I thought you might like this one! :o)

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  2. Yup, you thought correct good sir! :0P

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  3. I was checking out the FSB thread on this one re: a sub for the 2N3819, some posts seem to suggest that either a J201 or 2N7000 will work, is that the case? Someone said that they were used for the clipping, could a diode be used also? :0)

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    1. Any JFET could be substituted, but watch the pinouts because the J201 is DSG not DGS so you'd need to alter the layout or twist a couple of pins. Yes they are just being used as diodes so I suppose you could also use the 2N7000 or BS170 mosfets, or of course a conventional diode, but don't know how they might affect the sound. Remember if you use mosfets though, the gate and source need connecting instead of drain and source with JFETs.

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  4. Awesome, thank you matey!!

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  5. I know this probably common sense but,

    In general, you know when it says 'Vol 1 & Tone 2&3 to ground, Can I just run a wire from Vol 1 to tone 2 then a link to tone 3 and then wire from tone 3 to ground.. i.e, link them all then ground?

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    1. Yes mate, daisy chained like that is fine. Just make sure you don't create a potential ground loop.

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  6. Work cancelled, check.
    Parts sourced, check.

    Now to convince the wife that NOT spending friday night with me is a good thing! Fuck, I got my work cut out!!

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    1. Ha ha, I hope it works if you're giving up a Friday night session for it! :o)

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  7. Ha-ha, rude boy! Well mate it was worth it, this thing is awesome! I had a feeling that it wasn't going to go so well, but it worked straight off the bat. I took photos of my link placements too just in case (oh me of little faith). If anyone is unsure about how to apply the links & would like to see a photo, just holler! It's not the neatest work, but at least it shows how it all goes together.

    It sounds the tits & is effin loud! Mint ;0)

    Thanks Mark, great work again matey.

    VERIFIED 2N7000 VERSION ONLY

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    1. Awesome, I love it when they work first time with no headaches! :o) Send me the photo of the links and I'll put it in the main thread, it will definitely be helpful to some.

      And if the 2N7000 version is ok then the other version must be as well so thanks for verifying matey. How does it sound on the Mastodon riff? :o)

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  8. I'll email the photos to you mate. I'll send all I took & you can decide which ones are appropriate. It's a really nice sounding distortion with very good roll off for o/d sounds. It's perfect for those Mastodon riffs, thick & heavy but quite articulate. It's description is quite apt! This bitch is going straight in my board! ;0)

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  9. I build the 2N3819 version *verified*! Thanks Mark for your wonderful work, i really like your "flat" layouts;-)!

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  10. Just a little question. The little orange cap under the 200k resistor is marked "100n", is this correct? The other orange painted caps are 100p or 15p, so I'm not surre if 100n is the real value.

    Best regards.

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    1. Yes 100nF. I use that symbol when the cap is on consecutive rows because if you use one of the 5mm pitch cap symbols all the value text is obscured.

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  11. Built this effect yesterday late evening. Only difference is that i used a TL081 instead of a TL051 (no tl051 at local store). It did work at first but with extremely low output.

    I changed the 2N7000 an resoldered all suspicious components, checked continuity, triple checked if there were unwanted bridges and so on.

    When connected again, I could hear a great CRACK on the amp, and stopped working, even at low level.

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    1. Any hint? Maybe the IC's could have been blown? Not sure as everything seems ok.

      Best regards.

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    2. Well, 10uF cap with cold solder.

      Now it sounds..... like a very smooth overdrive. Trannies ok. Think i'm going to park this effect for a fortnight.

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  12. Ohhhh yeahhhh! Don't know what the f**k happened before with this effect, but sometimes let it parked a couple of days ("ponerlo en barbecho" as we say in Spain) works fine :P

    This evening just did pass a razor on every inter strip space in order to break any unwanted micro bridge, resoldered the board to volume 3 wire that had become loose and did solder again the 1MA pot (I used it this weekend in some other circuit's test and had no more 1m log available)

    Plugged guitar, circuit and amp, expecting again a low and mild output....and the walls of my room nearly explode! Surely tomorrow will get some killing looks on the neighbourhood besides my wife's "QUIERES DEJAR LA PUTA GUITARRA DE UNA VEZ????????" (Will you stop playin' the fu**ing guitar NOW?") XDDDDDDDD

    Mosfet version by the way. Tomorrow, to paint a new box in grey.

    Thanks once more for such a great veros, Mark!

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  13. Well, pedal finished:

    http://guitarrasimportacion.foroactivo.com/t449-capinc-effects-9-mad-bastard-mad-professor-stone-grey-distortion#6545

    (for your collection again)

    Next station: Keeley Compressor 4 Knobs, let's hope in the next week i get all the components from Tayda

    Have a good evening!

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    1. Excellent job Javi, thanks for the pics

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    2. Thank you Mark. Just one question. I really love the sound of this pedal, maybe in these few days y becoming my high gain favourite, but I find it TOO noisy. All high gain pedals get noise, but it think this one is too much. Not sure is using a TL081 instead of a TL051 may be the root cause, or should try with other inverter (4096) trying to get a quieter one.

      Any hint?

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  14. I have just built the 2n3819 version and it is not working properly. When you turn it on you only get a LOUD high pitched squeal. When you turn the pots it tunes the pitch of the squeal. I have checked the board, layout, and solders 3x. I have even tried to test this with an audio probe and the squealing starts immediately at the input on the board. I have tore the board and pots out of the enclosure and hard wired a battery snap and jacks to the board with the same results. Could the ICs be bad, can I test them? Thanks J

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    1. What voltages you have on the IC pins? That could tell something...
      +m

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    2. high pitched squeal sounds like a solder bridge. i get them all the time when i'm trying to find circuit bends on my builds.

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    3. TL051CP....
      Pin#1=0.19 #2=3.77 #3=3.46 #4=0 #5=0.19 #6=3.77 #7=7.56 #8=0

      CD4069ube..... Pin#1=3.71 #2=3.7 #3=7.61 #4=0 #5=3.59 #6=3.66 #7=0 #8=0 #9=7.59 #10=0 #11=7.56 #12=0 #13=7.6 #14=7.6

      Also, I have checked for cold solders and solder bridges 3x. I have done everything from reflow solder, examine under a magnifying glass and run a razor between all the tracks. It still squeals like a stuck pig. I can send pics if people are interested. This has me stumped. Thanks again for all the help.

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    4. I don't notice anything completely off in those readings.. Grounds are where they should be as well as + voltages. Bad component comes to mind?

      Anyone else have any insight?
      +m

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    5. This comment has been removed by the author.

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    6. Not sure if this would help, but this is the only high gain effect that I did really need to get input grounded, to avoid oscillation on bypass mode and tame feedback / pops and so on when activated.

      Anyway, this is a ver high gain and impedance pedal, so, at high gain / volume stages will squeal. You have to play with volume / distort knobs to avoid high squeals or feedback.

      (This is at least, the way that my unit works)

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    7. I reflowed all of the solder again as a last ditch effort and grounded both input/output jacks instead of just the input. It works perfectly now....so idk, the main thing is that it works great and is so fn loud and high gain its epic!!! I need to order some audio taper pots as I only had linear on hand and as soon as you turn the knobs to 9 O'clock its almost full bore.

      I have also played with the input cap to get a little more fullness and have settled on 22n. It thickens it up a bit without losing the clarity. I went all the way up to a 33n but felt that it was starting to get a little fuzzy.

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    8. Nice one, glad you got it going. I'd always take a ground wire to both input and output socket. They SHOULD ground through contact with the case but you don't really want to rely on that because a poor or intermittent contact can cause problems.

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  15. I always ground inmput and output socket, What I meant was that in this effect, besides the in/out sockets, I had to ground the board imput, as I had oscillation on bypass mode.

    Never use to do this, even in high gain effects like the Distortus Maximus, but with the Stone Grey was mandatory and was the only way to tame the beast and get rid of the switching pops.

    Best regards

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  16. Really love this effect, but as stated before, it seemed to me too noisy and uncontrolable.

    The only difference between this pedal and my usual ones, were the pots. These ones were purchased at my local store. Not just were way more expensive than Tayda ones, about 2 euros each, but the 50k ones, 47k to be more exact, were plastic made. A conductive plastic anyway but when operated, their behaviour were not exactly linear but not what I can call log. So in one Tayda order I added 2 50k log and one 1Mlog. Today i installed'em.... and holy shit, it seems not the same effect!. Its sound and effect is nearly the same, but noise has vanished, and the control of the unit is fine and smooth now. With the former ones, couldn't get the volume beyond 11 o'clock, and the distortion one was very moisy. Now I can use the pots in their whole extension, without noise from the unit. It seems incredible how a 0.50$ can beat a "heavy duty high design panel pot" 4 times expensiver.

    BR

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  17. This comment has been removed by the author.

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    1. 6 CMOS inverters

      http://www.ti.com/lit/ds/symlink/cd4069ub.pdf

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  18. Hello! Tell, please, CD4069ube is а logic chip? Thanks!

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  19. I want to know the replacement for TL051?

    thanks

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    1. Try any single opamp like TL071, TL081, TL061, LM741, NE5534, OP07...
      +m

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    2. honestly I've build Stone Grey using another stripboard layout (not from this site), its alive BUT there's no distortion at all...I am using 4069 with different letter code not CD nor UBE,

      I am lazy to do debugging, I will try to build again using layout from this site and using your Opamp suggestion.

      thankyou for the great site

      greeting from Indonesia

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    3. I built it per this site layout using CD4069UBE, TL071 (will likely swap for a TL051, supposed to have better specs) and 2N7000x2. No issues, just make sure you get all the links where they double up five places (blue circle holes). This is an amazing sounding pedal.

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  20. and here goes my version of this, stacked with a sweet honey pre the grey distortion, demo as well! went on with NE5534 instead of the TL051.
    http://www.youtube.com/watch?v=YZqQLVe8gsQ
    http://instagram.com/p/Xns2-AxWIy/

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  21. What is the importance of the CD4069 being a 'UBE'? My favorite parts suppliers do not specify any suffix :S

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    Replies
    1. It's unbuffered, as opposed to the BE which is buffered. The supplier will need to confirm which they are.

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  22. got mine completed today (2N3819 version). built stock, it sounds great. I then modded mine for more low end for use with a bass, and it sounds great with a bass now too.

    pic:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/BJFE/SGD-01.jpg

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    1. Thanks for the pic John. But I need your gutshots, they're my favourite pics because your builds are so immaculate :o)

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    2. here you go ;-) :

      http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/BJFE/SGD-02.jpg

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    3. Could you tell me something about your Bass mods?
      I also play bass so i'm interrested in making this pedal work for bass as well.


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  23. just experiment with changing the 2n2, the 10n and the upper 47n cap with higher values. I went with 100n's in all three positions.

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  24. BTW, I didn't have any TL051's when I first built mine so I used TL061's. my TL051's arrived Saturday, so I tried one in it and there's almost no difference between the two. I might even actually prefer the 61 since it has a little more mids and a slightly smoother distortion to it.

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  25. I've built both the JFET and MOSFET versions of this. The MOSFET is much harsher than the JFET one. I don't like it to be honest. The JFET is so much smoother and in my opinion the best distortion that I've built so far. It's so tight but still so open and clear. Proper video coming soon!

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  26. Hi mates,

    Just a quick question, mainly for the ones that have built this effect recently. I've just built two new ones for a client, and both work ok, and get a really high gain distortion but the tone control is subtle, really subtle, just to not simply say that is useless.

    I remember that the first I built, the tone was not very sensitive, but in these ones is really useless. I've been checking the schematics and there's nothing wrong.

    Do your tone controls feel sensitive or are subtle to say the least?

    BR

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  27. I've got the JFET version on breadboard now. I like this one very much. And they are not lying about the good string definition.
    Only thing is that it is a bit noisy on the higher gain/volume settings.
    I believe the many "antennas" on my breadboard might have something to do with that.
    But i also used a TL071 instead of a TL051. Can this also be a reason it's noisy?

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  28. Still got a sort of noisy "hum" on higher gain and volume settings after soldering. Anyone else has the same experience?

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  29. I've read that the noise issue might be a common thing with the CD4069 IC's (CMOS)
    Does anyone have any suggestions for some hum suppression?

    (honestly, i still have to box it)

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  30. Yeeehhh....
    Boxed it and most of the noise is gone. Just a little on highest distortion settings.
    It even makes difference when the bottom of the enclosure is open or not.
    Now a nice graphic and add to the board :)

    up next... Deep blue delay and snow white auto wah

    Thnx for the layout!

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  31. Hmmm. Just built one of these boards and the input impedance is an issue. Wonder if the original has a buffer before the input? Squeels like a pig on my test rig, but once i place TU-2 in front of it - all the squeeling is gone.
    +m

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    1. Nope, the original doesn't have any buffer before the input. I made one of these using this vero layout and had no problem with squealing!

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    2. It tamed down a lot when i boxed it, but with hot enough pickups the squeel is there. When all the pots are maxed. I think it's ok, but still made me wonder.
      +m

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  32. cd4069 replacement?can't find it here...any options?

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  33. build it with the 2n3829 and i found it really great! i only used lin pot cause that's what i have for now. i also tried to mod it so i can have both layouts in one with a switch but my plans didn't work out. i made a daughter bord 4*5 and mound it before the 2n3819s so i cound chose between two types but the signal was still running through 2n3819.
    Mark do you know if there is a way to do this? thanks anyway

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  34. Hi,

    Can you explain what I can do about the pop I get when switchin on and off? I ground the input when the effect is off so that should not be the problem.

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  35. Ok, I've built this one up carefully over the last few days. Clearly not carefully enough, I was so confident of it working on first test. No such luck.
    I've got no output at all.

    Here are the pin reading from both chips.

    1. 3.15
    2. 3.05
    3. 7.40
    4. 0.00
    5. 3.93
    6. 7.38
    7. 0.00
    8. 7.44
    9. 7.48
    10. 0.00
    11. 7.50
    12. 0.00
    13. 7.49
    14. 0.00


    and

    1. 0.00
    2. 6.47
    3. 6.86
    4. 0.00
    5. 2.04
    6. 7.49
    7. 6.86
    8. 0.00

    I've just built up an audio probe but have no idea what I should be expecting to get anywhere. If anyone has any ideas as to what I can test to try and get this working it'd be most appreciated.

    Cheers

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    Replies
    1. I think you've either got an issue with the position of the links or your soldering. Pins 9, 11, 13 and 14 of IC1 are all linked and yet 14 is showing 0V. Likewise, pin 7 of IC2 is also connected to those other points by a solid connection, and yet that is only showing 6.86V. You definitely need to critically look around there to see what the problem could be.

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    2. Thanks for the quick reply. I listed the Pins in the wrong order. Pins 8 -14 I showed in reverse. Sorry. That will also be the case for the IC2 . (5-8 will be reversed). For some reason I thought that they were counted down from the top on the second side. With this in mind does that suggest I've got my links correct? I must say, I triple checked these links when soldering and was very confident they were good. I'm getting a lot of humming when I touch the pins on the pots and I do get a very low signal when I touch the veroboard. Would that suggest a grounding issue? Thanks again

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    3. perhaps I should'nt have taken this on as I don't really understand how the circuit works. Can anyone offer a brief explanation oh how this works (signal flow etc)? I've used an audio probe and can hear two weak/filtered signals at the inverrting and non-inverting inputs of the op-amp, and and also at the output pin (a weak signal). I guess this is because there isn't much difference between the 2 inputs.
      I have a signal on pins 2 ( out 1) and 5 ( in 3 ) on the hex inverter. Nothing on any of the other pins. I just need a pointer or two to help me find the point in the circuit where I'm losing signal/ have a bad component or a bad solder joint ( although I have already reflowed everything once). Cheers

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    4. Noooo, you've never taken on too much! The signal flow is:

      Input
      2n2
      14k7
      IC2 pin 3
      IC2 pin 6
      200K
      10n
      IC1 pin 1
      IC1 pin 2
      47n
      IC1 pin 5
      IC1 pin 6
      4u7
      10K
      Volume 3
      Volume 2
      Output

      Check each side of each component and see exactly where you lose signal.

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    5. Ace, I'll check that now. Thanks

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    6. Ok, turns out I wasn't getting far at all. This is where I got to before the signal just became inaudible.


      Input ( we can reference this as 10/10 for signal volume)
      2n2 (filtered)
      14k7 (I've used a 15k here as I didn't have the 14k7. I suspect this is the problem. There is a huge drop in signal. 3/10)
      IC2 pin 3 (3/10)
      IC2 pin 6 (3/10. Surely this should be louder than the input?)
      200K ( Absolutely no signal on the other side of this resistor).

      Could the 15k resistor be the issue?

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    7. It's more likely to be the voltage you're getting on pin 3 that is causing the problem. The voltage is too high, it should never be that high. What voltage are you getting on row 9 where the 2 x 1M and 470K meet? The two 1M resistors are a voltage divider which should be half the supply voltage and so around 3.75V. This is the reference voltage for pin 3 via the 470K resistor and so shouldn't be anything close to 6.8V.

      Are you sure they are both 1M resistors?

      Delete
  36. Ok, so from the voltage divider I have have 4.46v on the lower side of the 470k resistor, but on the the top side that connect to row 4/ pin 3 of IC2, is 5. Definately both 1M resistors for the voltage divider.

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    Replies
    1. Even 4.46 is too high at the junction of the voltage divider. If after the protection diode and 100R resistor your supply is 7.5V, then the voltage at the divider should be exactly half that (assuming you're using a metal film resistor with probably a 1% tolerance). It will swing a little one way or the other if the resistors deviate slightly in value, but it should be very close. I wouldn't expect you to be getting 4.46V there unless your supply reading (at IC2 pin 7, row 6, IC1 pins 9, 11, 13 & 14) was 9V.

      One thing I do note is that you're showing 6.86V on pin 3 AND pin 6 which is next to it, so I would be immediately suspicious that the cut underneath the IC isn't clean, or there is a microscopic solder bridge under there somewhere which is connecting pins 3 and 6.

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  37. Ok. I recut underneath the IC2 and now have 2.77v at pin 3 and 2.91 at pin 6. I'm getting a way better output now. Infact I have a good signal up until pin 6 on IC1. The signal at 5 is fine. I assummed the 100pf cap links pin five to six. I've tried three caps in here with no luck. No output any further than pin 5

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    Replies
    1. IC1 could possibly be faulty then. Did you socket or solder? I'd also check the 4u7 which is also on the pin 6 row

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    2. I used a socket, for the first time ever! I will replace IC1 and the 4u7 cap tonight and see where that gets me.

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  38. Ok, I'm getting somewhere. In fact I believe I'm very nearly there. I took both chips off, rechecked links and fully drilled out some cuts. I've ditched the IC sockets and soldered the chips straight to the board. I replaced the IC2 chip with one that works!! Now I'm getting a decent signal all the way up to Pin 5 on IC1.
    So at this point the distortion knob is working and I am getting an amplified signal out of IC2.
    I cannot figure out why I'm not getting a signal from pin 5 on IC1 to the pin 6 row. I have replaced both the 100p cap across pin 5 and 6 of IC1, I have also changed the 4u7 ( just to clarify this a 4.7uf?) and check for unwanted bridges as well as cutting between strips.

    From what I can see its just this output stage that isn't working. Does the 22n cap do the tone filtering? Thanks again.

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  39. Still no luck, I'm going to buy a new hex inverter. Its the only thing I can think of that I haven't already replaced.

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    Replies
    1. It may just be a single channel that is damaged, in which case you could use pins 3 and 4 instead of 5 and 6 (you'll have to re-jig things so you can use those pins, like move the 470K, 2 x links and fill in the cut). You also have the other channels on the opposite side but it would be a lot of messing about because some of the links would need to be removed which would mean desoldering the IC which runs the risk of damaging it more.

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  40. Good idea, I'm just not confident enough to deviate from the original layout. I'm going to order another hex inverter, but before I do I just want to be sure that I should be receiving a high signal at pin 5 ( which I am ). I thought that the inverters output the opposite of its input, in which case pin 6 would be outputting nothing/ very little (which it is). Should it be that pin 5 needs to be low so you get a high output to pin 6 and therefore high to the output of the whole circuit?
    If so, it could be that I have a problem further back in the circuit which is making pin five high?
    Just a thought.....

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    Replies
    1. No, it's acting as an amplifier. 5 is the input, 6 is the output.

      Delete
  41. Ah ok. I wish I understood a bit more of how the circuit worked. I am learning more everyday and definitely have more patience than I did! I'll make the order then.

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  42. The only reason I suggested it it is because pin 2 is high and pin 3 is low. I just figured that 5 and 6 would behave the same way.

    ReplyDelete
    Replies
    1. 1 & 2, 3 & 4 and 5 & 6 are all separate channels.

      So 3 is low simply because it's not being used, which is why I suggested moving all the connections to 5 to pin 3, and all the connections from 6 to pin 4.

      Delete
  43. Sorry, yeah, in my last post I meant "because pin 2 is high and pin 1 is low"

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    Replies
    1. I wouldn't expect any DC voltage on pin 1 because it had a cap before it which blocks DC

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    2. Try this fix before putting a new IC in. It uses the 3 & 4 channel instead of the 5 & 6
      http://i62.tinypic.com/2rh8xfs.png

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  44. Ok. I've clearly misunderstood how this is meant to work. So are you saying that I should be getting a signal on pin 5 ( when probing I am getting a good signal that I would consider to be a high/ acceptable output level) and a higher/ amplified signal on pin 6?

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    Replies
    1. Are you talking about DC voltage measured by a multimeter, or audio signal using the probe? The path of the audio signal is as above, ie for that IC:

      10n
      IC1 pin 1 ) Amplifying channel A input
      IC1 pin 2 ) Amplifying channel A output
      47n
      IC1 pin 5 ) Amplifying channel B input
      IC1 pin 6 ) Amplifying channel B output
      4u7

      So you should get an audio signal all the way along that chain. When you said high and low I thought you were talking about the DC voltages on the pins.

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  45. Sorry, that was really misleading. Yes, I am talking about using an audio probe. So I am receiving a small/ low signal at pin 1 on IC1 after it has passed through the 10n cap, then a high/loud signal on pin 2, a signal of equal volume, and sound, on pin 5 then nothing on pin 6 and beyond.

    ReplyDelete
    Replies
    1. Is the signal on pin 1 similar to the signal before it, like at IC2 pin 6? If so then yes that is perfectly normal. The signal at pin 2 has been amplified by the stage, and likewise the signal at pin 6 should be higher than pin 5 because it's the output of another stage of amplification.

      Delete
  46. Yes it is. Ok. Hex inverter ordered. Hopefully that'll sort it. Thanks again for all your help, I'll let you know how it goes.

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    Replies
    1. Try the fix I posted the layout for above first. The cmos ICs are as susceptible to static as mosfets are so you may have a faulty channel

      Delete
  47. Ok so a new hex inverter arrived today, As I feared, I still have the same problem :( Positive side is I now have a spare hex inverter for a future project. Apologies Mark, I hadn't noticed the link you posted the other night with the alternative layout. This is my next move to try and rule out anything to do with that strip on the veroboard that pin 6 sits on.

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  48. I've made up the alternative layout and have a similar problem to before. I have a good signal up to pin 1 on IC1 but barely any signal on pin 2 or onwards. I've tried three different hex inverters now. I've tried the hex inverter soldered straight to the board. I've replaced the 100pf caps over pins 1 and 2 and 3 and 4. Still no luck with this one. Please check the pics out I've taken, just to make sure I'm not going mad and have done something ridiculous. Admittedly the underside is looking a bit uglier than it had done.

    https://www.dropbox.com/sh/013agdcjoayf9zx/AACuWIyYWPf-g1Sybsnikyz6a

    Thanks

    ReplyDelete
  49. would a 4049ube work instead? I have a couple left over

    ReplyDelete
    Replies
    1. No. The chips have different pinouts.
      http://www.ti.com/lit/ds/symlink/cd4049ub.pdf
      http://www.ti.com/lit/ds/symlink/cd4069ub.pdf
      +m

      Delete
  50. Hi, I've made the vero for this circuit but does anyone know where I can find some TL051 chips for a reasonable price in the UK. Also I noticed the TL051 comes in different flavours TL051ACP etc. does it matter much which one I use. Cheers

    ReplyDelete
    Replies
    1. I don't know any sources in the UK, I tend to buy all my ICs from various sellers on eBay. Don't worry about the suffix as long as the one you're ordering is DIP8. Those digits normally denotes type (DIP SOIC etc), temperature range and packaging method and so it's really only the type that matters to us because all the other variations will be suitable.

      If you can't get one then try a TL071 which I'm sure will work perfectly well.

      Delete
    2. Thanks Mark, I've heard the TL071 doesn't give quite the same sound so i'll socket and try both when i get some, cheers for clearing up the suffix thing :)

      Delete
  51. Hey guys, I'm hoping somebody will lurk here and help me out

    I have just built the SGD (fet version/TL071) and here's what I notice: once I take out the transistors from their sockets, there's no change in sound - I still get nice distorion - as if they were not supposed to have anything to do with the audio path. The distortion pot works OK with or without the transistors in their sockets. Is this natural for this circuit or have I done something wrong (I obviously did the regular things - checked cuts, links, ran a knife in between the strips, etc)

    Any thoughts anyone?

    thanks in advance
    Bart

    ReplyDelete
  52. Hello guys! I built this effect, versione 2n3819, and works great, Thanks and Thanks forma all the work you do! With this share to 38-40 effects are built from tour site...:D

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  53. Hello guys! I found the IC CD4069UB and not the CD4069UBE. Are they the same thing?

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  54. Hopefully someone's still watching this post and can help me out.

    Tried my hand at this build, but I can't get it to work.
    There's distortion, but the signal is almost only low and mid, no highs - tone all the way help's somewhat, but I guess that's not how it's supposed to work. Also, when distortion is past 3 o'clock, there's a loud, low pitched squeal.

    I get the "full" signal up until IC2 Pin 6. It's good going in (pin 3), but not going out. It used to be a muddy signal, but after reflowing there's only a super quiet signal.
    I've tried reflowing the ic sockets, reflowing everything, making sure there's no unwanted connections, tried another chip (both TL051 and TL071). Probably gonna try switching out the socket itself, but then I'm all out of ideas.

    I'm afraid I don't have a multimeter at this time, so I can't check any voltage.

    Any help/ideas at all is appreciated.

    ReplyDelete
    Replies
    1. Nevermind this! Turns out I was counting the pins wrong... followed the signal and a resistor was badly soldered, all good now!
      Thanks for a great layout, Mark!

      Delete
  55. hello, have I constructed the version 2N7000 with tl051 and it sounds very well, but the potenciometro of volume makes something strange, to the maximum the whole sign goes away and nothing sounds, also he does not start dreaming even spent the half more or less, much does not matter for me because I always put the volume in a position compared with the clean sound and do not touch it, but can this be affecting the sound of the pedal? thank you

    ReplyDelete
  56. Hi, I just built it and it sounds as it should......all pots work as expected, but I am getting little distortion at max (like when on "9:00"). Only sub part is a TL071 for IC2........... voltages as follows

    Pin 1: 0,17
    Pin 2: 3,92
    Pin 3: 3,58
    Pin 4: 0
    Pin 5: 0,17
    Pin 6: 3,92
    Pin 7: 7,85
    Pin 8: 0

    Voltage is 9,19

    Any idea why I am not getting enough gain ?

    Thanks in advance !!

    ReplyDelete
  57. BTW I think I spotted a potential mistake.......C8 is 100 nF in all the available schematics I am finding such as this (http://3.bp.blogspot.com/-P2RCqMsl__A/TxLM0MEtCJI/AAAAAAAAAio/rVtTwB3v83g/s1600/Mad+Prof+stone+grey+schem.gif) .......the layout calls for a 10n cap ?

    ReplyDelete
  58. Both layouts have a 100nf cap as per the schematics. Not sure what discrepancy you're seeing. I built mine off this layout (2N3819), many months ago and I just opened it up to check the value and it's 100nf as it should be. Double check and make sure you have updated layouts.

    ReplyDelete
  59. Just FYI - I tried all three versions of this - the two included here and the one in the forums, and all of them were just incredibly bright (trebly) and there was nothing I could do to tame it down. If that is what you want this is the build for you.

    ReplyDelete