[sdiy] High-power Moog ladder VCF

[lanterma at ece.gatech.edu]

I asked Kevin if I could repost this, and he gave me the thumb-up...

- Aaron

On Dec 9, 2010, at 3:05 PM, Kevin Lightner wrote:

> Btw, I made a crazy thing the other day:
> 
> A discrete Moog ladder filter made from Minimoog schematics using very large and mostly high-current components.
> 2N3055 TO-3 transistors only, big orangedrop caps, big resistors, etc.
> Just a crazy idea to see if I could make one that worked and for the hell of it, could run on higher voltages and current.
> It worked the first time I powered it up. :)
> 
> Technically I didn't make a VCF tho.
> I left off a couple trannys normally used for converting voltage to current.
> Instead I added a 2w pot and control the current directly.
> I guess it's a CCF. ;-)
> 
> This thing is about a foot long or more and maybe 6 inches wide.
> Silliest thing you've ever seen, but amazed because it works and sounds great.
> I can run it as low as 4 volts and as high as what my PSU puts out, 30 volts each rail.
> Gain structure changes considerably of course, but that's kinda the fun of it all.
> 
> So I guess I made the first Moog filter that can drive a speaker directly without an amp? ;-)
> 
> Here's a pic.... http://www.synthfool.com/bigfilter.jpg
> 
> Kevin