Turnabout from AT to Charlie Brown?

[morbidalex666]

The subject pretty much sums it all.
I don't even know if the CB is based around the same schem, cause I can't seem to find one.
So, is it possible to base a Charlie Brown around the Turnabout layout?
Values to be changed?
Thanks and Cheers!

[Boba7]

Nope, the Charlie Brown appears to be a slightly modded boc of rock with added contour pot.

[Boba7]

End of page1 and page2, I'm trying to guess the best I can, though no one seems very interested...
http://www.freestompboxes.org/viewtopic.php?f=7&t=14501

[morbidalex666]

Thanks for that!
Pity no one seems to care for such a nice sounding JTM45 in a box pedal...
Oh well...

[Boba7]

If you build the dirt side of the Box of Rock and add a contour pot and replace the 100nf in the tone section by a 10nf, you'll most likely build a very very similar sounding circuit!

[thesmokingman]

there's a reason nobody cares about it and that is because it's a JHS design ... as a company they're not exactly known for coming up with their own mods/designs.

[Boba7]

Yeah you're absolutely right.
Especially cloning a runoffgroove design wasn't a particularly good idea...

But I feel that a LOT of boutique companies do exactly the same and no one complains about them. Some of them even seem to be quite respected.

Anyways, from the demos I heard the Charlie Brown seems to sound really good, like a less bassy and more flexible Distortron, which is already a really nice circuit. The modified tone section makes it less bassy than the Distortron (so no need for the sub switches) and the contour pot adds flexibility.

And let's not forget the Distortron is basically a Mosfet BSIAB2!

[Boba7]

If I were to build a Charlie Brown like, I'd build the dirt part of the Box of Rock (aka Distortron with no switches) and add that tone control :


Could be a really great circuit...

[thesmokingman]

having had a box of rock in the past and using it quite a lot I have some thoughts on your plans. I'd build out the box of rock, add the gain and subs toggle from the distortron and if you feel it necessary to have a contour knob I would use the one from the pinnacle instead of the one you showed which I believe came from the bsiabii mods on ggg. if I recall correctly, the pinnacle contour alters the second order filter on the output of the pedal rather than the tone control.

[Boba7]

I should have a look at the pinnacle, thanks!

The contour circuit I posted isn't the GGG one, it's from AMZ, and it looks interesting cause it allows a very flat curve as well as a more or less pronounced medium cut. The contour is basically a medium control. And the bass response isn't as exaggerated as the original Box of Rock schem.

Don't know when I'll build one but it's nice to get new info about it!