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Tuesday, September 29, 2015

Electro Harmonix Muff Fuzzes

Around the same time that the EHX Big Muff was first released in 1969, Mike Matthews also released the Muff Fuzz. It was unrelated to the BMP other than the name, and came in the same small enclosure as the LPB-1 that plugged straight into the guitar. Later it was re-released in a floor pedal as the Little Muff Pi and more recently as the Muff Overdrive. In the mid-70s, the circuit was updated, moving away from the Fuzz Face based transistor circuit to a design based around the popular JRC4558 op-amp. I've laid out both versions below and both should fit in a 1590a.



34 comments:

  1. Transistor version not working :(
    Tested on pcb and breadboard

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    1. That would be because I had the 100k resistor that was supposed to go from the emitter of Q2 to the base of Q1 going to the collector of Q1 *facepalm*

      It's fixed now. Sorry about that!

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    2. no entendi la respuesta a mi tampoco me funciona...
      gracias por leer esto.

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  2. I built the op-amp version using the PCB. Verified. Nice little quick build, with a vintage sound that's quite close to the original.
    Thanks for another wellmade layout!

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    1. You're welcome! Thanks for verifying!

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    2. Please i built it and didnt work, any advice?
      I used 1n60 as diodes and jrc 4558 the opamp

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  3. I built the tranny version last december and it didn't work.
    I see that it has been fixed.
    Now it works perfectly.
    Thanks!

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  4. Hi, can I use 1n4148 for 1n34a? I've seen that they should be similar for these kind of application...

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    1. Yeah you can use them. The 2 don't sound the same, but you're pretty safe using them here.

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  5. hi, i try to made Hi. I'm trying to make muff fuzz transistor version. But why not work? But I've followed all you post here. help me :( thanks

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  6. Hi. I'm trying to make muff fuzz transistor version. But why not work? But I've followed all you post here. help me :( thanks

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  7. Hi. I'm trying to make muff fuzz transistor version. But why not work? But I've followed all you post here. help me :( thanks

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  8. is it correct that sounds with low volume?

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  9. I Tried the opamp version and didn´t work
    Any Advise?

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  10. I only have at the moment 46nf capacitors, what would happend if i used those instead

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    1. Might sound slightly more trebly, but should be fine. You could also put two of your caps in parallel to make a (almost) 100n cap.

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    2. Hey thanks just finish mine with 47nf caps and 4148 diodes no so much fuzz but a really nice boost overdrive

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  11. I built the OP Version with 1 1n4148 and 1 1n34A, really warm sound, also by mistake i put a 120k resistor instead of a 100k.

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  12. Hi, I built the transistor version on breadboard, but with Q1 2N5089 and Q2 AC187, I like the sound but I like more with a "Gain knob", can you help me?

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    1. Easiest way would be to put a pot (100k, 250k, 500k would work) before the circuit. Run the input into lug 3, lug 1 to ground or run a 1k resistor from lug 1 to ground, and lug 2 to the In pad on the board.

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    2. Ok great, but would it be the same as the pot of the volume of the guitar, some other option that does not affect the input signal only the amount of distortion? And another question, what is better? Q1 AC187 (germanium NPN) + Q2 2N5089 (silicon NPN) or Q1 2N5089 + Q2 AC187? THANK YOU

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    3. It would be the same as lowering the volume control on your guitar, but it's an often used method with this kind of circuit. Another option would be to do the Mark Hammer mods described here: https://www.diystompboxes.com/smfforum/index.php?topic=77456.0

      As for the transistors, I think most hybrid silicon/germanium fuzz face variants I've come across use a silicon for Q1 and germ for Q2. But at the end of the day, go with what sounds best to you.

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    4. Hello, yesterday I tried to put a pot B10K in series with R5 2.7K (in the output of the Emitter of Q2) and I could lower the distortion!
      What I do not understand is what is the electrolytic capacitor shown by Mark Hammer, because seeing the scheme of the Fuzz Face there is also a 22uF electrolytic capacitor in the output of the Fuzz pot (B1K)

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  13. i have made the transistor version today by etching the pcb layout, and i use the exactly value of the all component, but Unfortunately there is no fuzz tone, its just clean fat tone :( :(

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  14. I built the opamp version and its pretty quiet. I don't hit unity volume until about 2 on the volume pot. Is this normal for this circuit? I have an original muff fuzz here and it hits unity at about 10 oclock, it seems most of the ones on youtube are the same.

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    1. The same thing. Also built opamp version, and it also sounds way too queit, I have to put the gain all the way out to have just a pretty weak fuzz tone.

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    2. From what I've seen (can't remember where sorry) most schematics for the IC version are missing a 470 K resistor in parallel to the diodes. This would massively increase the gain in this part of the circuit. Theres also a small cap in parallel, 100 pf or 47 i think.

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  15. sir can i use s9014 in this circuit??

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  16. Would the red 1n34a diode mark in the layout be the anode or the cathode?

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  17. I love this pedal!!! Nice sizzle to it. If I want to make it louder, can I change the value of a component, or do I need to add a full boost circuit?

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