adding a sub-switch to a fuzz pedal

[BassVD]

Dear colleagues

A friend of mine asked me to build him a Hyperion fuzz, but he'd like to have a footswitchable sub-boost, "like in the old Ashdown amps," he said. Now, if I remember correctly, in the Ashdown amps with such a switch, it were the subharmonics that were boosted, so it was not really an octave down. Now I was wondering if it's possible to add some thing like that to a Hyperion, and how?

There is this Ashdown/Dr Green Octa Dose pedal that seems to simulate the circuit from the amps, but I can't find any schematic or even gut shots. I've also been looking into pedals such as the DOD Meatbox and Bifet; Mantic Effects makes clones of those two: the Density Hulk and the Thug. I could only find the vero layout for the bifet, so nothing for the other ones. And I'm a bit dubious about the bifet if it would be a good match to add to the fuzz in order to achieve a "sub blast".

When I asked my friend if an octave-down would also be fine, he said that that would be okay if I really, really couldn't get to boost the subs. He wants "to create sonic mayhem". He's also going to use the pedal on bass. I figured that's a useful piece of info, as subs aren't that effective on guitar, in my opinion. So I'm still looking into that. But as far as I know, that will be more difficult than the sub octave.

For the octave down, the Joe Davisson Shocktave might do the trick, as it has a fairly low parts count.

I'm hoping that one of you guys can still come up with something for the subs. So any help would be much appreciated!

[Rob Strand]

I thought some Ashdown amps use this chip:
http://www.diystompboxes.com/smfforum/index.php?topic=111960.0

Not sure if that covers "old Ashdown amps"

I'm also not across the details of the chip because the block diagram is a little high level.

[BassVD]

Seems like that chip is hard to find..
And then again, I don't have a schematic or layout for a pedal that can be used to achieve the effect my friend wants.

Anyone else got an idea?