JFET overdrive schematic and vero

Stompboxes circuits published in magazines, books or on DIY electronics websites.
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Nocentelli
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Post by Nocentelli »

I found a bag of J201 JFETs recently and thought I'd try out an overdrive. I came across the ramble fx marvel drive and had a play with it on the breadboard. The normal channel on it's own sounded very nice, with a great range of gain but was a little bright for my taste, so i turned the filtering at the end of the circuit into treble roll-off pot.
JFET drive_schem_nocentelli.jpg
Incidentally, after I'd done the layout below and was just about to strip the breadboard to solder the bits together, I tried out some 2N5457s from a bag of discards, just randomly plugging a few different ones into Q1 and 4, and they all sounded pretty ok without even checking the voltage.
JFETdrive_vero_nocentelli.gif
JFETdrive_vero cuts.gif
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vanessa wrote: 20 Aug 2007, 17:51 You can't arrest someone for reverse engineering something.

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storyboardist
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Post by storyboardist »

Here's a perf board/PCB layout if anyone wants it. I laid it out so folks can just use 50k trimmers to bias Q1 and Q4.

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Frank_NH
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Post by Frank_NH »

Thanks for the vero layout - very nice. So, I've built the Marvel drive already - is this enough different to be worth a build in its own right? How does it sound? Thanks!

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Nocentelli
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Post by Nocentelli »

It's very close to the Marvel drive in terms of the schematic, just a couple of changes noted in my post. I made it to save one jfet, and to tame the brightness a little.
vanessa wrote: 20 Aug 2007, 17:51 You can't arrest someone for reverse engineering something.

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