Sunday, 14 February 2010

Mosrite Fuzzrite



Below is a modded version as per J's comments below. Give it a try and see what you think:


24 comments:

  1. Thanks for all your generous info. I built this silicone version Fuzzrite using your layout and although it is a really good sounding square wave fuzz, I wasn't getting that synthy, compressed attack, Stephen Stills - Buffalo Springfield fuzz I was hoping for when I started this build. It comes pretty close at lower depth pot, higher volume pot settings but not quite there. I added parallel resistors across the depth and vol pots, (1M and 100k respectively) to approximate the original pot values which worked well but doesn't have a big effect on the sound - but then I stumbled upon what might be the missing ingredient in this circuit and is missing from all schematics and layouts I've seen on the internet. Upon close examination of several original silicon Fuzzrite pics, it appears there is a 22k resistor between lug 1 of the depth pot and lug 3 of the volume pot. This lowers the gain drastically but adds that character to the sound that was missing before. It might not be for everyone as you really have to crank it to get unity gain and there isn't much boost available. Could be a cool option were it wired to a toggle or a second stomp which would give a huge boost when switched out. I could be missing something here. What do you think?

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  2. Hi J and thanks for the info. None of the schematics I found for the Fuzzrite included this resistor so I've just gone off the info I had, but it certainly sounds like a worthwhile addition, particularly as a switchable option. I've added a modded version to the post which uses a 2 position DPDT to switch the resistor in and out. I'll give this a try as soon as I get a chance.

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  3. I did some more searching and I found a forum post where a guy mentions the necessity of the 22k resistor but I was mistaken about its placement as it is hard to see from the available photos. Apparently the resistor goes from lug 1 of the depth pot to lug 1(ground) of the vol pot. This makes all the difference! Now it doesn't lose so much volume and has that original character. So much for the boost switch idea! Although switching this resistor in and out might still be a useful option as it is still a higher gain pedal without it, just not quite true to the original sound. BTW I LOVE the tag board version you wired up! Being an amp guy, you gotta love the look of that! Very manly! hehe P.S. Where can you purchase tag boards like that? Gotta get some!

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  4. There you go, I've updated the layout. I'm in the UK so I get my tagboard from:

    http://www.ampmaker.com/

    But if you're in the US you could try:

    http://www.turretboards.com/

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  5. Thanks for the info! That ampmaker.com site rules!

    Check this out! Here's a pic where you can clearly see the resistor:

    http://files.effectsdatabase.com/gear/pics/mosrite_fuzzrite-germanium-2_002.jpg

    BTW, adding bias adjustment pots to germanium pedals is very popular, why not silicon versions too? I know how to do this on a Fuzz Face/Tone Bender Ge type circuit but what about this silicon Fuzz Rite circuit? If you were to add a bias adjustment pot in this circuit would you happen to know which resistor too replace with a pot? Thanks. J

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  6. That pic shows the resistor connected from lug 3 on the depth pot to ground. I'll alter the layout later. In terms of biasing it, the transistors get their supply via the two 470K resistors in the middle of the layout, going from 9V to the transistor collectors. So it may be worth trying swapping those resistors for a couple of 500K trimmers.

    I've heard people suggest that tweaking the resistor values isn't as crucial to getting the Fuzzrite sound as the transistor selection, and it's suggested that you go for something quite high gain for Q1 and quite low gain for Q2. So maybe it would be worth trying that first.

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  7. Very good sir! Sorry for my confusion about the lug numbering. I must have dyslexic vision! hehe
    I've heard conflicting info about the ideal transistor gains in Fuzzrite. On one forum some folks insist that q1 should be low gain and q2 high gain, the opposite of a Fuzz Face/Tone Bender type circuit. Guess we'll try both.
    Also, I built a little turret board circuit(found one locally which I modified to make it smaller) and I swear it sounds better than the identical circuit, same transistor pair on a pc board. I don't know why but it does...

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  8. The 22k properly connected gives a midrange character that is true to the original and not much overall volume change as opposed to where I had it before...in the wrong place! I experimented with different values and ended up with an spdt toggle switch to change between the stock 22k and a 220k which yields a nice fat low mid boost/shift. A very useful feature!
    Replaced the 470k bias resistors with a pair of 500k trims and arrived at 47k as my favorite value for each. Much better sound quality and range of fuzz than the stock value.

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    Replies
    1. Thanks for the info, guys! About the 22k resistor discussion, not truely clear for me yet!!!! (sorry) Is the properly connection from Depth (lug 3) to ground, or from Depth (lug 1) to ground?

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    2. Depth pot lug 3 is correct Gabriel. Look at the two layout pictures at the top of the page, and you will see the difference. You want to use the second layout, with the 22k resistor on a switch.
      I hope this helps.

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    3. I have done this mod on all the Fuzzrites I have built - it really is worth it.

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    4. Thanks, Beaker. I was missing that second layout! Helped a lot.

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    5. I would like to post here some clips of the one I built, with no 22k resistor at all:
      https://soundcloud.com/gargaman/fuzz-01
      https://soundcloud.com/gargaman/fuzz-02
      https://soundcloud.com/gargaman/fuzz-03
      https://www.youtube.com/watch?v=tJqhDjr7Zvg

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  9. Thought you might be interested to see a couple pics of my ptp turret board customized si FuzzRite style build which your tag-board build inspired. Additions are a Tone control(Garnet 18watt style) 22k/220k stock/fat switch and the mystery on/off switch which kicks this thing into awesome guitar synth territory that has blown everyone away who's heard it. I'll have to post some clips. Cheers!

    http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs769.snc4/66960_439345456844_615806844_5453003_7639326_n.jpg

    http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs391.ash2/66960_439345461844_615806844_5453004_3287501_n.jpg

    http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs391.ash2
    /66960_439345451844_615806844_5453002_3811139_n.jpg

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  10. Excellent job J, I love it. And yes I'd be very interested in clips.

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  11. what is the on off switch that makes guitar synth sounds? please post a final layout of your modded fuzzrite, i am interested to give this a try.

    cheers

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  12. hey guys, thanks a lot for this, I made the circuit on veroboard (after a stint on my solderless breadboard) and am very chuffed with the sound. at first it didnt sound right because I had the 2nd transistor the wrong way round! DOH! I'm pretty new to this. I have been attempting to make pedals for a year or so with little to no success however recently realised a lot of it was down to my soldering technique... anyway that's another story.

    This is the second circuit I have made successfully. first being an anderton TSF kit.

    Anyway when I had it on the solder less breadboard I discovered a neat trick, if you swap out the vertical 2nf cap (excuse the laymans terms, as I said I'm new) for a larger cap you get a nice bass boost. I set mine up on a DPDT switch with the 2nf cap on one side and 22nf cap on the other. big jump I know but I think it makes the pedal sound AWESOME. (I'am in a sludge/doom band so would say that)

    anyway I have also noticed that the drive/gain knob on the amp makes a lot of difference to the tone. If its too low the pedal sounds very thin but just a few notches up and it beefs out again. I'm not sure if this is just an amp specific "problem" but it doesn't bother me. I use a line 6 spider 50w 1x12 combo for circuit testing (I know I know, it sucks, don't get me started)

    anyway thanks again, just found this blog and the circuits on here are fantastic, Mastotron next :-) talking of which actually the diode I used in this is actually a 1n4148 (which is what it suggests in the mastotron circuit) I also used 2n3904 transistors.

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    Replies
    1. Excellent, glad you like it, and thanks for the info about the mods you did.

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  13. hmmm doesn't seem to be a diode in the mastotron, my bad... now why did I buy those 1n4148s....

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    Replies
    1. Don't worry you'll have plenty of things to use them in as you go through the blog! I think I must have about 1000 x 1N4148s

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  14. Hi there, newbie signing in. I LOVE this pedal - I have had to build three so far as people keep asking me for one. As far as I am concerned, this is what fuzz is all about.
    Keep up the good work guys, it is much appreciated!

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  15. Hey folks,

    I built this successfully, however there is an outrageous amount of high end noise. Any suggestion on how I could curb this nonsense?

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  16. I'll start the new year with this fuzz today.
    :-D

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  17. I just finished it.
    I'm totally in love with this fuzz!!!!

    Thank you!

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