Simple voltage controlled low pass filter

[markusw]

Space Drum sweep filter perhaps, my circuit is here somewhere......

Thanks for the tip! 
Is it this one?
http://img.photobucket.com/albums/v517/uncle_boko/multispacefilter1.gif
Just one of the envelope followers of course.
This would be one more quad opamp plus a couple of other parts including 5 pots...ouch...

Considering that the wolde mess now already populates nearly 5 breadboard stripes I think I have to stop adding modules soon. I don't have the faintest idea how large the PCB(s) is/are gonna be with the circuit as it is right now but I don't want to put it in a rack. 
Actually, I would like to use one of those sloped Hammond aluminium enclosures. The come in different width's. I hope it doesn't need a 20x11,3 inch....

I would love to have a cool envelope filter included because I'm currently very keen to check out a couple of VCF's like the Moog low pass.  Suppose the Space drum envelope generator in combination with the Moog would be an interesting combination. However, the whole thing is already pretty large and tone control is still missing. In total it will be around 20 chips. Therfore, I think I will include a breadboard area like Charlie did on the ADA flanger PCB and just skip the second half of the LM13700 for now.  I'm working on it for over one year now, with a couple of "distraction" projects in between  . Therefore, I would love to finish this project. Will still take a lot of time doing the layout for it.

However, the Space drum envelope with a nice VCF might easily be the next project.
BTW, what filters did you use with the Space drum follower?? 


Regards,

Markus