Switchable TS mods

[MikeH]

I was going to add a couple of switchable mods to my 808 clone, but after a little research I got excited (over excited probably) and decided to put it in a D sized enclosure (I just scored a bunch really cheap) and build in as many switchable mods as possible.  I want to be able to make it stock or mod, at the flip of a few switches.

Here's what I've got in mind thus far

-High gain mode
-Fat switch
-rotary diode selection
-TS9/808 mode

I was also going to try some opamp switching, a la beavis audio opamp stacking style:  http://beavisaudio.com/Projects/ScreamerLab/index.htm

Anyone have any other ideas for for mods that can be switched on and off?  Keeley mods require too many components to be switched to use a single switch.  I had also thought of things like input cap swtching, but I don't think thats a little reduntant along with the "Fat" mod switch.  Any suggestions?

[ubersam]

You could also make the caps in the negative feedback loop, parallel to the clipping diodes, switchable. I used three different values in one of my builds, 100pf, 220pf & 330pf. You could also make the caps in the lowpass filter, after the first opamp stage, swithable to vary the corner freq. In my previous build I used 0.22uf (723hz), 0.27uf (589Hz), 0.33uf (482Hz). Another thought, how about a switch to turn the buffers (input, output, or both) into boosters?

EDIT: here is a pic of the build (my first build) I was talking about - http://i112.photobucket.com/albums/n188/ubersam/DSCF0117.jpg

[MikeH]

That's a really cool build, it's quite similar to what I'm goin for.

You could also make the caps in the negative feedback loop, parallel to the clipping diodes, switchable.

What exactly would this do?

[ubersam]

That's a really cool build, it's quite similar to what I'm goin for.

You could also make the caps in the negative feedback loop, parallel to the clipping diodes, switchable.

What exactly would this do?

Thanks. In the negative feedback loop, with the clipping diodes, the caps round out the corners of the clipped wave form so that they are not so square. Another thing the caps do is limit the harsh ultra high freqs. In short, in that position, caps that are larger than the stock 51pF will result in a rounder clipped wave form and smoother highs. There is a detailed explanation of this in a thread from a few days ago. I'll see if I can find it and post a link.

EDIT: here it is - http://www.diystompboxes.com/smfforum/index.php?topic=52242.msg394265#msg394265 -- see MarkHammer's explanation below my post.

[Danny G]

Sounds cool.  Be sure to file detailed reports to us with as many pictures as possible, heh!  \m/,