This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, October 10, 2017

Lumpy's Tone Shop Lemon Drop/ZII/Series 7

Here's a simple little overdrive designed to emulate the old Vox 4 and 7 series amps (used by the likes of Jimmy Page and the Beatles). Pots are board mounted and it should fit in a 1590B easily. I've added a trimmer to bias the JFET at little easier. Schematic and voltages can be found here on FSB. From the manufacturer:

The 7 Series Overdrive captures the aggressive qualities of the solid state preamp found in the 4&7 series amps by using a pseudo hybrid setup consisting of a specifically selected silicon transistor for the first stage which adds a distinct bite and growl.  That pushes an FET stage into clipping adding some warmth, sustain and amp like dynamics to the tone and feel.  The end result is a highly effective emulation of the amp and a unique sonic blend that could be characterized as a "fuzzy overdrive." 



8 comments:

  1. The 220nFs in your layout are just 22nFs in the FSB schematic.

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    1. Fixed. No idea why I read them as 220n. haha

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  2. Verified! But I use 100K trim instead to get the bias of Q2 around 4.5V. Great sounding pedal, love it!

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  3. where does q1 go, and where does q2 go?

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    1. Q1 is on the left (marked by EBC) and Q2 is to the right (GSD).

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  4. how can i get cleaner sound? with the gain pot all the way down still gives me a distorted sound, already try to set the trimpot to sending less volts to the 2n5457 but doesn't work

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    Replies
    1. Try reducing the value of the 10k resistor on top left side of the board (coming off lug 1 of the gain pot to ground).

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