Thursday 15 July 2021

Fuzzhead Fx AN-602 O.D.

Just is a variation of a russian big muff. The base eq of the circuit is preserved i. e. dark, bassy and heavy but there is much more gain and volume on tap. There is also an old school inductor based Mid Boost circuit at the recovery stage that boost and saturate frequencies at 800Hz.



 
 

 


29 comments:

  1. Congrats on 1000 layouts - super impressive!

    After you posted some layouts based on proaudio gear (the tape saturation and the disruption). Have you thought about doing layouts for more proaudio stuff? I think it's uncharted territory for a lot of guitarists... but there's tons of potential there like Origin Effects having a 1176 rack compressor made into a pedal, the BJFE Sea Blue EQ being based on a Neve EQ and the Colour box from JHS which is basically a Neve Preamp. The Hudson Broadcast is also based on an RCA mic preamp, if I'm not mistaken.

    But there's so many unexplored circuits with schematics and info out there - like the Grampian 636 spring reverb that is supposed to saturate deliciously with germanium transistors (Arturia made a plugin emulating it... it was also used by Pete Townshend as a distortion unit.. oh and it's vintage gear experts Soundgas' favorite spring reverb unit). I've also heard a video of the Telefunken Echo Mixer crunching heavenly. Stuff like that. It might require some experimentation and breadboarding, though, I realize. (Perhaps I should get into the game myself instead of cupping my hands)

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    1. Love those old school discrete circuits!
      Downloaded the schematics for Grampian 636 (sounds great in the soundclips !) and Telefunken Echo Mixer. I guess it is doable make pre amps out of them but as you said, it will require some breadboard time.

      There is also Bell & Howell Filmosound 385 Film Projector Pre Amp which Walrus Audio 385 is baed on...

      So which ProAudio circuits do you have in mind?

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    2. Oh, BTW, Andy at Vero p2p Layouts is working with the Neve Pre Amp. Worth checking out!
      https://vero-p2p.blogspot.com/2021/07/neve-preamp.html

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    3. Exactly the stuff like the two units mentioned. Doesn't need to be proaudio per se, just studio units that double as guitar tone tools (like the examples mentioned and something like the Echoplex Preamp) and "saturation" for other instruments like drum machines.

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    4. There is tons of Colour "mudules" here, all really interesting stuff.
      https://www.diyrecordingequipment.com/pages/the-colour-format
      But it requires an external power and pre amp circuit called "Palette".
      You don't happen to know other DIY suppliers for studio / "proaudio" circuits?

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    5. Cool! I'll follow his site and see what he comes up with.
      It could also be something like a FET-version of the preamp in the Echolette NG51 tube-based tape delay (a favorite of Dungen's guitarist).
      The Helios passive EQ (+the small Helios amp circuit for make up gain after it) is supposed to add great color as well.. but that, too, might be too complicated for vero (and for a guitar pedal).

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    6. GroupDIY is full of 'em... My fellow dane Jakob Erland aka. Gyraf has tons of 'em on his site: https://gyraf.dk/schematics/schematics.html

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    7. ...most of them are way too complex for vero, I fear, though.

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    8. Yes, most of them is quite big....but Grampian 636 isn't!
      Would love to try to build a clone of the preamp section.
      There are two schematics avaiable:

      https://soundgas.com/wp-content/uploads/2019/01/Circuit-Diagram-Grampian-Reverberation-Unit-Type-636-DEST4328.pdf

      https://ekadek.com/grampian-636-spring-reverb-schematic/

      BUT I need to figuree out which parts of the circuit that can be omitted but is a possibility that the reverb driver part is too integrated with the preamp part...I don't know yet.

      I will create a separate post for this and redraw the schematic.

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  2. Cool! I like the idea of an inductor based mid boost. I'll definitely give this a spin sooner than later. Cheers Fuzzhead. Thank you for what you do!

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    1. Cheers! Looking forward to hear your thoughts if you build it!

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    2. Fuzzhead I have a question .. The inductor are 100mH, it’s the same value with 100uH?

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    3. Hay Marios!
      No 100uF is not the same as 100mH.
      100mH equalls 100000uH!

      I used this or similar.
      https://www.mouser.se/ProductDetail/Bourns/RLB1014-104KL?qs=AC4ivEYFOTCZeKctbbzO7g%3D%3D

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    4. F@&c… almost I finished the board and I don’t have this conductor ,, I’m waiting for 1 week to got it … but can I add something else there instead the conductor until got the 100mH?

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    5. I mean inductor … sorry :p

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    6. I'm afraid you really need a 100mH inductor to have a functioning Mid Boost control.:-/

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  3. Wow!!!! When I return from holidays .. I built it !!! Awesome 😎. Thank you fuzzhead

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  4. I finished … I put for now the 0.1 mH ( this a had ) .. and next week I receive the 100mH… I test it and the sound is soooo good ,,it’s dark heavy sound … love it ….. thanx again fuzzhead

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  5. Hi! Great layout, sounds awesome with BC550C and Kd521! Any chance to make the mid-boost switchable without big volume-difference? Cheers

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    1. Thanks!

      I have a break from building and rawing layouts at the moment but will take a look if it is doable when Im back on track.

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    2. Thanks! That´d be a blast! Looking forward to it!

      BTW: How can I send you requests or layouts I traced?
      Cheers again!

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    3. You can send your tracing fildes here:
      anders.sjodal at gmail.com

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  6. Hey Fuzzhead, i find your designs super innovative and inspiring. Especially the inductor om this one - do you have an ideal of how you could create some sort of inductor based low mods boost for a fuzz face circuit like the dunwich Cthulu Fuzz?

    Would it be possible to take the same approach like here withva trimpot to the emitter? Or any better ways for a passive low mid boost for a fuzz?

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    1. Thanks for your kind words.:-)

      It is definitely doable to convert it to a bass boost stage. However, we need to know frequency to shoot for. 80Hz, 100Hz, 120 Hz?
      At lower frequencies a higher value inductor is usually required, maybe in the 500mH 1,5H range. They are getting increasingly hard to source but I guess a wah inductor or an audio transformer can do the job as well.

      Also, I need to do some calculations of the cap and resistor that connects to the inductor.

      Very cool idea though, I very much prefer the sound of inductor tone controls over the more synthetic sounding gyrators which basically have replaced the inductors..

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    2. Here is a very useful calculator:
      https://www.calctool.org/electronics/rlc-circuit

      For a bass boost at 87Hz, you can sub the 330nF for 3,3uF and the 100mH for 1H. Keep the 82 ohm resistor. The Q is is pretty much the same as the Mid boost, a bit a above 6 Q.

      If you can't find a 1H inductor, you can use two 500mH in series.

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  7. Fuzzhead, could you do a layout of the Big muff "metal muff" please? I've built just about all the other muffs and variants thanks to you and the rest of the fellas on here. I'm missing the metal one and can't find a layout anywhere and I'm not seasoned enough to do a layout from the schematic myself. But anyways, thanks so much if you or another guru could do this to add to this great library of pedals.

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    1. Believe it or not, the Metal Muff is a clone of the Boss Metal Zone with a different mid control and a top boost. Start here and see if some of the mods on the linked schematic would get you exactly what you're looking for:

      https://dirtboxlayouts.blogspot.com/2020/11/boss-mt-2-metal-zone.html?m=1

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    2. Thanks a bunch Sebastian. The component number schematic is perfect! Should be a breeze to mod with that and the metal muff schematic I have.

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  8. Hey guys, I need some help with this. Just got my 100mh inductors in and have built this twice. It sounds great, but both times I have very low volume. Seems to be a lower volume than the amp even. I made sure to check for bridges on both builds and second time I checked each component to make sure it was working properly and that the values were correct. What am I missing here or what could the problem be? Any advice would be appreciated because I can tell this is a keeper and am itching to get it working properly.

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