Saturday 4 May 2013

Skreddy Top Fuel

Another great fuzz pedal from Marc, and I felt a nice one to add to our collection.  I thought with 8 transistors this would be a bitch to get into a 1590B as a vero layout, but it turned out pretty comfortable in the end.

Info about the original:

Skreddy Pedals™ Top Fuel:
strikes a balance between high gain, sustaining distortion and articulation.

    First, I trim out the woofy, mushy, congested bass.  Then amplify (a lot) and distort using mosfet soft clipping (twice), for a fine-toothed, modern, tube-like distortion character.  Then trim out the harsh and fizzy high end and use a mid-hump tone stack that's centered around 700Hz.

    The string attack is always preserved throughout the entire range of the fretboard, regardless of the sustain level.  Tonal emphasis is placed on the midrange in order to showcase the player's technique.







10 comments:

  1. Replies
    1. Yeah it does. I didn't think I'd want to build another fuzz pedal for a LOOONG time, but this one has me seriously tempted.

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  2. It's verified!

    I don't know if a noob like me should verify, but it's done! Yay! I didn't have 620r so I used 680r. Also didn't have BC109Cs so use BC109B for Q2, BC108B for Q7, and 2N2222A for Q8.

    It sounds great and it has that distortion/fuzz hybrid sound. I love it with sustain cranked! Also it cleans up well with guitar volume control.

    I'll try with BC109Cs if I ever get hold of them.

    BTW, what is the purpose of 620R? I wonder what it would do if I use the original value.

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    Replies
    1. Excellent, thanks for verifying! The 620R is the source resistor for Q1, and the ratio between that and the drain resistor sets the gain for the first stage, there would be slightly more gain with the 620R you used. I expect any differences between the two would be minimal.

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    2. Ahh I see. Thank you for that info. I get paranoid if I don't use the actual value of the components for some reason but I would just stick with it this time. It sounds pretty good anyway :)

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  3. I get a lot of hiss with mine that increases with the sustain pot... What might cause that? Otherwise sounding good.

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  4. I randomly socketed Q1 (BS170) and tried with another one and the hiss reduced about 50%, but still some left, any quesses what would be the next one to swap?

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  5. I dont like the BS170 and replaced it with a 2SC1222.
    I also replaced Q3&4 with NTE123A transistors.
    Both are NPN silicon.

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    Replies
    1. Forget me. I tried and tried and now Q1-Q8 is BC238B NPN si (Hfe 200) to make this unit behave equal to a regular Muff.

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    2. For the same reason i used to change R56K to 44K and R33K to 11,5k.

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