Can anyone verify this Top Fuel circuit?

[benallison]

http://supervelcroboy.wordpress.com/2008/08/20/skreddy-top-fuel/

Looks good! I really want a Top Fuel, and was wondering if this circuit is indeed accurate.

Anyone built/compared it?

[sean k]

Well, I've looked at it and copied it and it looks like the breadboard might be comming out because I've got all that stuff on hand. The Mosfets and germanium diodes as clippers looks really interesting.

[benallison]

Yeah! It's designed to nail the lead tone from the second solo in Comfortably Numb. From what I can tell it really is the perfect smooth lead pedal.

It's been discontinued so the choices are either pay crazy "collector" prices or diy!

But before I try this build, I just wanted to see if it is, in fact, accurate.

[benallison]

Monday afternoon bump.

[WGTP]

WTF?  Oh, I get it.  Nitro Methane  Interesting.  Mosfet clippers replacing the standard ones in a BMP.  (LED's could be used for similar effect and simplicity).  Also 1st mosfet stage could be used thur out for all mosfet.  Yep, worth a breadboard trial...  The BS170's and 2N7000's are interchangeable, but the pin out has to be flopped...   Thanks for sharing.       

[Ben N]

Uh, maybe I'm not supposed to say this, but they did a whole thread on the Top Fuel... um, elsewhere  ... WITH participation by Marc Alfs, "skreddy" hisself, so you might want to check... elsewhere. He's a great guy, confirmed the schem, offered mods, part substitutions, etc., and totally does not endorse the nutty secondary market.

BTW, the number of booteekers who participate over there is quite interesting, at last count including, besides Marc, Nic from Catalinbread and Paul Cochrane. I guess this is in the spirit of "if you can't lick 'em, might as well join 'em." While I understand the impulse to prevent dissemination of one's design, these guys seem to have figured out that the professional cloners will get them anyway, whereas a fair presentation of a good design in the DIY world will only enhance their reputations, which will outweigh any lost incremental sales in the long run. OTOH, if the booteek pedal is just a clone with goop or an appnote circuit, I guess there is every reason to keep on fighting.

[benallison]

TGP? HC? Freestompboxes?

You tease you!

[Skreddy]

I don't like the way that schematic is drawn all crazy, but it looks right.  I haven't verified the components or their values, though; so it's possible SVB got a few things wrong.  If you re-draw it or just annotate a standard BMP drawing, it'll be easier to follow.

BTW, I'm still offering the Top Fuel for sale; there's still a shopping cart on its page.  I just don't want to keep it in my main lineup anymore, and I want to put something more of a standard BMP in its place instead.

But do build one if you have the time.  It is a bit different, and you might like it.

[benallison]

umm... you're the absolute coolest dude in the world.

thanks for being cool with us diy'ers (i'd barely call myself a diy'er though... useless hack is more like it).

all the best marc!