DEFX Atomic Duck and Q2 build questions

[itisjanuary]

Finally the last of the parts for these pedals are coming in... can't wait!

On the Atomic Duck:

1) What is the CLR connection used for?

Current limiting resistor! Duh. Only needs to be installed if I connect the LED

2) digi2t pointed out in the past that the e/o pads are for envelope out (which I plan to use), but what are the BP and GND pads below it for? Anyone know yet? If not, I'll be experimenting to find out!

For both the atomic duck and the Q2:

1) For the smaller capacitors (100n, 22n) is it ok to use box or mylar caps or do these need to be ceramic monolithic?

2) Heat sinks necessary?

Boy is my soldering rusty!! I can't wait to box these!

Thanks, all!

[digi2t]

The BP and GND pads are not used. They are vestiges of the original units. Ignore them. Or experiment. As you wish.

For the caps, use whatever you prefer (and fits).

No heatsinks required.

[itisjanuary]

Right on, and thanks! I know the BP pads aren't used, but if I can get an extra cv input or output for additional modulations, that'd be great.

I'm wondering if the BP would allow for CV control over a bandpass width or something of the sort. It may not play well.... we'll just have to see.

The envelope out will be quite useful for additional filters in chain.

[digi2t]

BP doesn't stand for bandpass. It stands for bypass.

I think there was a different scheme originally planned for the bypass, and it was changed up for the true bypass scheme you see there.

[Strategy]

Atomic Duck is awesome. One of my bandmates took off with my build of it to run his Roland TB-303 through for extra filtery "acid" basslines.
I've resigned myself to the reality that he's just appropriated it and I'll have to build another one 
This is not the first build that this has happened too either
But in this case I think it speaks to the excellence of Atomic Duck.

[ElectricDruid]

This is not the first build that this has happened too either
But in this case I think it speaks to the excellence of Atomic Duck.

While it might speak to the quality of the Atomic Duck, it doesn't say great things about the quality of your bandmates!!

[idy]

What do the 2 LEDs do? I see them close to the resonance trimmer, parallel to it.

[antonis]

What do the 2 LEDs do? I see them close to the resonance trimmer, parallel to it.

IC3_C soft clipping..
(they're placed inside NFB loop..)

Or did I miss something..??

[ElectricDruid]

What do the 2 LEDs do? I see them close to the resonance trimmer, parallel to it.

IC3_C soft clipping..
(they're placed inside NFB loop..)

Or did I miss something..??

+1 agree. I think they're feedback limiting for the resonance. You see something like this quite often on state variable filters. It helps stop the filter running away into screams when it hits oscillation.

[antonis]

It helps stop the filter running away into screams

And ruin all the fun..