madbeanpedals::forum

Projects => General Questions => Mods => Topic started by: lespauldoc on December 26, 2014, 07:17:56 PM

Title: Sparkplug v1 mods: Opamp, transistors, clipping
Post by: lespauldoc on December 26, 2014, 07:17:56 PM
Greetings,
I'm curious to whom has experimented with the Sparkplug and some of its easily tweaked values. I've built 2 now, and have them before me to mess with this weekend. One has 2n7000s which sound a bit more biting/aggressive and the IRs are a bit more spongy/greasy to me. They have the stock opamp in them, but I think a mosfet opamp would match this better, or even a BurrBrown. I'm going to check these out in the morning as the kids are asleep---

Has anyone messed with these yet?

Title: Re: Sparkplug v1 mods: Opamp, transistors, clipping
Post by: lespauldoc on December 29, 2014, 08:50:06 PM
Ok: The 2n7000 is more aggressive/biting, but less overal gain and drive. SOUNDS FANTASTIC with a typical 4558 opamp though. Best choice IMHO.
As for the IRs, it sounds best with the stock chip and the 2272. The 2272 is a bit more hi-fi and clear, but the sag with the 2262 really makes it work.
Title: Re: Sparkplug v1 mods: Opamp, transistors, clipping
Post by: mandrewbot3k on January 08, 2015, 07:52:16 PM
thanks for the post.
Title: Re: Sparkplug v1 mods: Opamp, transistors, clipping
Post by: felipesareas on April 28, 2017, 12:39:56 AM
Please somebody help me:

I want to build it using the 2N7000. The Datasheets and the madbean PDF doc. sugest that the pinout for the IRF510 is Gate-Drain-Source. The same PDF says that in order to use the 2N7000, I should flip it 180ยบ. But the Datasheet for it displayed Drain-Gate-Source.

If that was right, shuldn't I swap legs 1 and 2 in order to use it? Sorry if my question is too dumb