Friday, 23 May 2014

X Fuzz by deadastronaut

I listened to the clip of this last night and thought it sounded awesome for such a small circuit, so had to do the layout.  Another bonus is that it uses common transistors so no searching for unobtainium, or having to get something in specially.






66 comments:

  1. Might sound good with a big muff tonestack!

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    1. Yes I was thinking exactly the same thing. My only concern would be if the losses are too much which may then need a recovery stage, but it seems loud to me so I think it should handle that passive tone control quite well.

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  2. Nice fuzz. Quick and easy build too. Verified mate!

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  3. wheres the in and out on the board?

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    1. Input to PreGain 3, Volume 2 to output. It's in the notes underneath the layout.

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  4. Out of curiosity regarding the diodes, is darkened side the flat side of the diode?

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  5. Darkened side is the cathode ( - ) if I am not mistaken...
    Really nice sounding fuzz there.
    I am going to have to get on this one too... (another fuzz . . . sigh)
    :)

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  6. Thanks for providing this! I've had my eye on this X Fuzz, very simple but what a ton of cool usable fuzz! (Some, if not most, fuzzes are simply unusable IMHO)...

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  7. Thanks for providing this!

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  8. devi's hyperion comes to mind :)

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  9. Well that's a little insane. Love it though

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  10. Does it matter what colour of led you use.

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    1. Yes because different colour LEDs have different forward voltages. Other colours will still sound good, but more than likely somewhat different because more or less of the signal will be clipped depending on the colour used.

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    2. So i take it yellow gives best results.That's the one color i don't have.I used red and it still sounded great but i'll get yellow so i can compare them.

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    3. I'm assuming deadastronaut will have tried other LEDs because he had it on a breadboard, and he must have thought the yellow ones sounded best as they're the ones he ended up with. But you may prefer something else, it all depends on the gear you're using and your tastes

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    4. Is it the forward voltage that's different or the forward current?

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  11. Built and tested. Creamy sticky fuzz. And super harmonics. Great job peeps! I am goin to build another for a friend. Sounds as it should... Thanks loads guys :)
    Vince

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  12. BTW i used a 1 Meg Lin reverse pot for the Pre-gain. Works very well. But the 500K Vol log pot could be looked over and maybe changed to a 250k Lin pot? Not enough variance for the 500k Log pot for my tastes. I'll try it.....? ....
    Vince

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  13. I'm questioning the 500k log pot as well. Mine seems to go too far, in respect to gain. If i turn it all the way up it begins to squeal and makes me think my amp is about to blow up ;-)
    What would u do to prevent this from happening?
    Otherwise this thing is amazing! Every metalhead on earth should have one of these!

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  14. hi guys...deadastronaut here , nice to see you guys are enjoying it, as for the bias pot i would go with 250k, stick with yellow standard diffused leds, and kick ass...cheers rob.

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    1. Hi Rob, thanks for the circuit. I did one for the X Rock as well but then reading a bit further in the thread, I noticed you changed it. So I'll add that layout when I've checked back on the latest version.

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    2. okey dokey.. yeah you know how it is with breadboarding....lots of coffee, whiskey, and late nights...:)

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  15. Maybe you could do a layout for the combined X-Fuzz/X-Rock with clipping switching between the 2? I think it was WhiskeyMadeMeDoIt posted the schematic towards the end of that thread? Anyway great work you do here, Ivlark! Thanks!

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    1. Yep I did! I like it. The 1uf cap between first and second stage should be changed to 470nf to get the synthy sounds to work better for both clipping types. I added a Big Muff Pi tone style stack to mine but I noticed that the bias pot ( synth/jazz ) changed the filter after it was adjusted. To combat that I used a emitter follower after the second stage. It works for my purposes but ymmv. Lastly the final stage switching I have on the schematic is also completely optional. I like the ability to switch the end stage it goes from cool solid state to warm tubey sound. If you build it adjust the drain resistor on the bottom JFET a little higher. It has a bit to much gain. I will probably update my schematic when I finish tweaking my build. Have fun!

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    2. Oh yeah forgot to mention use YELLOW leds for the FUZZ and RED for the ROCK clipper.

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    3. Thank you, Whiskey! I hope you can post your updated schematic soon. Thanks for your work on this too. I am a bit of a noob but really wanna get stuck into this, this sorta fuzz is right up my alley.

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    4. Posted my updated schematic. I will have to post a demo soon. If you wait I'll have the PCB posted.

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  16. Hi all, could you please tell me if the darkened mark on the LEDs represent negative like an electrolytic or do they denote the positive side. Thanks for the help and all of the good work.

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    1. Yes with LEDs and electrolytic cap symbols the little mark is a "-" symbol

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  17. Hi,

    I am getting a lot of noise when the wires of pregain 2 and 3 are near each other. Do these have to be shielded?

    Many thanks

    Iain

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  18. Replies
    1. it shouldn't matter in this effect. just grab 2 2n5088's, put them in, and you should be good to go.

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  19. Finished my 1st tagboard pedal today, the X Fuzz. Sounds great but I have a couple of issues. Like a few others I get micro phonics in the upper 25% of the vol knobs throw. I saw a suggestion that it should be changed to an A250K, is that the consensus? Also the lower 10% of the throw of the pre gain cuts out the signal. Any suggestions for components to swap out to fix these issues.

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    1. Try a 4k7 resistor between pregain one and the vero and use a 500k linear pot.

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    2. Thanks Whiskey, I assume you mean the B500k for the Vol. Wouldn't that just change where the micro phonics started and not the sweep range of the Vol? Any info is greatly appreciated. I am a quick learner, just trying to get a grasp.

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  20. About that 1u is there +/- ? I have these tantalum parts and they seem to have + & -.

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    1. There is voltage on both leads of the 1µ, so non-polar would be best fot it. If you want to try the tantalum for it, positive to LEDs and negative to Q2 base. It may or may not work.
      +m

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    2. Thanks. And yes it didn't work. Both LEDs were alive but sound was weak.

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    3. Tantalums are not crazy about having voltage on both sides.. Try the highest value of non-polar cap you have in that position instead. Even 100n may sound right.
      +m

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    4. Do you reckon 4.7nF would do the job?

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    5. That may cut too much of lows.
      +m

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  21. Nice compact layout. I used BC549s and red LEDs and the sound isn't too far off the vid clip above, probably not quite as fuzzy/gainy but I think I'll try the yellow LEDs.

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    1. Put the yellows in and it sounds much better imo.

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  22. It doesn't work well on my circuit, i only have a weak overdrive. I use yellow LED low current (1.7V operating voltage), is it the source of my problem? Do you have any idea?

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    1. Hey, I'm having the same issue. Have you found a fix for that at all?

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  23. Is it OK to use a polarised cap for the 1uF? If so, which way round should it go?

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    1. Most likely, no. If you want to try it out, i said above: positive to LEDs and negative to Q2 base.There is voltage on both ends, so non-polar is the way to go.
      +m

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  24. I've made this and it appears to be working but I only get a tiny bit of gain out of it, sounding nothing like the demo. Has anyone else encountered this problem or does anyone know how to solve it?

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    1. What voltages are you getting at the transistor pins?

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    2. Do I test that by holding the negative and positive to each pin? (This is when there is a battery connected, right?)

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    3. Hey IvIark, just tested the transistors and I'm getting 1.64 and 2.72. Also, having redone the offboard wiring, the minimal gain is no longer a problem but another has come up, the fuzz works but at an extremely low volume. Any idea about how to fix that?

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    4. Another question- does the fact that it's not in an enclosure yet make a difference?

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  25. Hey dude

    With the pedal powered on, connect your negative probe to ground and connect the positive probe to the test point(s)

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  26. Has anybody tried other transistors? I seem to be out of those :)

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    1. Just try any other NPN transistor (check the pinout) and give it a go! Get some SIP sockets for your stash.

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  27. Built this just because I am on the quest to build every single fuzz thats been to find my ultimate favourite. Was pleasently surprised although there is a bit of background character and the pregain pot isn't correct. I always read the comments before i decide wether to build or not and did see the pot issue before building but thought what the hell its easy to swap a pot if necessary. Anway enough ramblings and to say this is an awesome sounding pedal and even though its not quite perfect i have decided i like it a lot and i would encourage others to build it as its a small box of joy. A massive thank you to |^|ark and Miro for this amazing site that fuels my evergrowing obsession.

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  28. Hi! First thanks for this awesome website!
    This is my first post here. I made few pedals already but I have a problem with this one. I guess it's a ground issue because there is a buzz going very loud when I touch the pregain pot. I checked for short circuit on the veroboard but it's fine. Apart from that it's working good. Any idea what could cause this issue?

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  29. precision : If I touch the metal part of the jack coming in the input, the buzz disappear.

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  30. Built it tonight. Sounds in-foo-king-credible. I added a couple rows at the bottom and used a spdt trough-hole switch I scavenged from some cheap gadget to make the diodes selectable, (would have used an enclosure mounted switch buy I wanted this to be a set-it-and-forget-it deal.

    Used some odd coloured (more of an orange-pink) leds I had around (1.6 forward voltage) and on the other side I used a couple 1n4746 (chosen simply for the fact that I had a bunch of those).

    Led side sounded great. Schottky side cutted the volume in half with no change in sound. Then I tried red leds, they made no perceptible change in the sound. Tried different led combination and finally settled with a yellow led + shottky diode that somewhat cuts the volume but gives a less harsh clipping. Cant really test it out loud since its 2:00am and my neighbours are just so much patient, but I can tell you, this circuit is LOUD.

    I get a bit of buzz (higher with the gain pot all the way up) but Im guessing it will go away after I set it in its enclosure.

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  31. Just did a build 2 days ago with red LEDs, and it sounds amazing :) Surprisingly good sounding fuzz for such a small and simple circuit!! Thanks!

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  32. Holy cow... This is awesome! Between fuzz and distortion and actually usable. Worth every bit of the space the 1590A takes on your board. :-D I used 680nF instead of 1uF. No problem.

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  33. Try Orange LEDs! Less woolly than yellow, a bit more on the Distortion side of things but less "ordinary" sounding than red ones. Love the thing...

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